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Found 2 structures.
Displayed structures from 1 to 2
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Structure type: monomer
Trivial name: isoquercitrin
Compound class: saponin glycoside, glycoside, flavonoid glycoside, flavonol glycoside, flavone glycoside
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Flavonoids constitute a large group of polyphenolic compounds naturally found in plants, which have a wide range of biological activity. Although flavonoids are beneficial to human health, their application is limited by their low bioavailability and poor water-solubility. Therefore, recently there has been a particular interest in glycosylated forms of flavonoids, which usually are better soluble, more stable, and more functional compared to their aglycones. Microbial transformation of natural flavonoids may be an attractive way of receiving their glycosylated derivatives in amounts sufficient for the research on the effect of glycoside group on compound properties and for further application of these compounds as ingredients of dietary supplements and pharmaceuticals.
glycosides, biotransformation, microbial glycosylation, flavonoids
NCBI PubMed ID: 28517915The vacuolar flavonoid profile of Umbellularia californica consists of 3-O-mono-, di- and triglycosides of kaempferol, quercetin and isorhamnetin together with eriodictyol 7-O-glucoside. The leaf exudate contained no flavonoids but did exhibit a small amount of scopoletin. The two growth forms of this species, a shrubby form from dry habitats and a coastal forest tree, exhibited identical flavonoid profiles. These observations were taken to indicate that the flavonoid profile of this species became established before the two growth forms differentiated. The flavonol profile of Umbellularia is consistent with profiles reported for other members of the Lauraceae.
variation, flavonoids, flavonol glycosides, Umbellularia californica, Lauraceae
Publication DOI: 10.1016/S0031-9422(00)89642-9The determination of nine different flavonol glycosides from Tilia using reversed-phase high-performance liquid chromatography (HPLC) and micellar electrokinetic chromatography (MEKC) is described. The analytes were monitored by on-line diode-array UV detection to identify peaks as quercetin or kaempferol derivatives. MEKC is confirmed as a useful complementary technique to HPLC.
Publication DOI: 10.1016/0021-9673(93)83449-3This paper describes the flavonoid constituents in Agathis australis from a wide geographic range and completes a comprehensive survey of the flavonoid chemistry/chemotaxonomy of New Zealand conifers begun in 1984. Flavonol 3-O-glycosides and biflavones of the cupressuflavone and agathisflavone types are shown to be the predominant flavonoids. NMR data for these biflavones with varying degrees of methylation are presented for the first time. The flavonoid profiles of A. australis and three other species of Agathis show a high level of uniformity, and in this respect are closely related.
chemotaxonomy, flavonoids, Agathis australis, Araucariaceae, biflavonoids, cupressuflavone, agathisflavone
Publication DOI: 10.1016/0031-9422(94)00783-PFlavonols were characterized and measured in experimental (n = 46) and commercial (n = 9) red raspberry juices by HPLC/diode array spectral techniques. Samples were prepared using minicolumns, packed with Polyamide 6. A fraction eluted with methanol contained eight or fewer quercetin glycosides, quercetin, and kaempferol. A second fraction eluted subsequently with 0.5% ammonia in methanol contained three flavonol glucuronides, two flavonol forms, aglycons, ellagic acid, and its derivatives. Quercetin 3-glucuronide was the major flavonol in experimental and commercial juices, respectively (mean of 54 and 51 ppm), and a flavonol presumed to be quercetin 3-sophoroside was the second primary compound (means of 29 and 33 ppm). In addition, 36 flavonol forms were measured in trace amounts. The mean total concentrations of quercetin and kaempferol forms, respectively, in experimental juices (n = 45) were 118 and 3.6 ppm and in commercial juices (n = 7) 121 and 3.4 ppm, respectively. The mean total flavonol concentrations in experimental and commercial juices were 122 and 125 ppm, respectively. Influences of cultivar (n = l0), processing method (standard, high-speed centrifugation, depectinization, diffusion extraction, vacuum and osmotic concentration) and environmental factors (geographic origin, maturity, harvesting method, mold contamination) were evaluated.
Publication DOI: 10.1021/jf00035a025From the roots of Clematis stans three new oleanane-type triterpenoid saponins named clemastanoside A, B and C, and two new lignan glycosides named clemastanin A and B, have been isolated together with three known triterpenoid saponins, huzhangoside B, C and D, and three known lignan glycosides, (+)-lariciresinol 4-O-β-D-glucopyranoside, (+)-lariciresinol 4'-O-β-D-glucopyranoside and (+)-pinoresinol 4,4'-O-bis-β-D-glucopyranoside. In addition, from the leaves, four new oleanane-type triterpenoid saponins, named clemastanoside D, E, F and G, have been isolated together with five known triterpenoid saponins, hederasaponin B, kizutasaponin K_<12>, huzhangoside B, sieboldianoside B and huzhangoside D, and three known flavonoids, isoquercitrin, rutin and quercetin 3-O-β-D-glucuronopyranoside. The structures of the new compounds were elucidated based on chemical and physicochemical evidence as follows : clemastanoside A, 3-O-β-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl oleanolic acid 28-O-(4-O-acetyl)-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (terminal rhamnosyl 4-O-acetate of huzhangoside B); clemastanoside B and C, 3-O-β-D-xylopyranosyl- and 3-O-β-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-β-D-galactopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester, respectively; clemastanoside D, 3-O-β-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl ester; clemastanoside E, F and G, terminal rhamnosyl 4-O-, 3-O- and 2-O-acetate of 3-O-β-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamno-pyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester, respectively; clemastanin A, (7S, 8R)-3-methoxy-3', 4,9,9'-tetrahydroxy-4', 7-epoxy-5', 8-lignan 3'-O-β-D-glucopyranoside; clemastanin B, (+)-lariciresinol 4,4'-O-bis-β-D-glucopyranoside.
Ranunculaceae, lignan glycoside, Clematis stans, oleanolic acid bisdesmoside, hederagenin bisdesmoside, quercetin glycoside
NCBI PubMed ID: 8582022Two phenylpropanoid glycosides, a new one, lamalboside (2R-galactosylacteoside) and the known acteoside, the flavonol p-coumaroylglucoside, tiliroside, 5-caffeoylquinic acid (chlorogenic acid), along with rutoside and quercetin and kaempferol 3-O-glucosides were isolated from the flowers of Lamium album. Esters of glycosides were obtained as mixtures of trans/cis isomers. The presence of flavonoid p-coumaroylglucosides links Lamium to other members of the subfamily Lamioideae.
phenylpropanoid glycosides, flowers, Lamiaceae, Lamium album, acylated flavonoids, lamalboside, 2R-galactosylacteoside, trans- and cis-tiliroside, trans/cis isomers
NCBI PubMed ID: 7766391From the leaf of Rhodedrndron ellipticum β-carotene, sitosterol, uvaol, quercetin, myricetin, quercitrin, myricitrin, hyperin, quercetin 3-glucoside, and the new aglycone quercetin 5,4′-dimethyl ether were characterized by spectroscopic analysis and/or comparison with authentic samples.
quercetin, Rhododendron ellipticum, qricaceae, myricetin, quercitrin, myricitrin, hyperin, quercetin 3-glucoside, quercetin 5, 4′-dimethyl ether
Publication DOI: 10.1016/0031-9422(94)00905-9Two novel hydrolysable tannins, potassium brevifolincarboxylate and acaindinin, together with eight known tannins-1-O-galloyl-β-D-glucose, 1,2,3,6-tetra-O-galloyl-β-D-glucose, corilagin, geraniin, acetonylgeraniin A, euphormisin M-2, repandusinic acid A, and chebulagic acid, as well as two flavonoid glycosides-quercetin 3-O-β-D-glucoside and rutin, were isolated from Acalypha indica. Their structures were elucidated on the basis of chemical and spectroscopic evidence.
flavonoid, Euphorbiaceae, Acalypha indica, Phenolic;, Hydrolysable tannin, Potassium brevifolincarboxylate, Acaindinin
Publication DOI: 10.1002/jccs.199700075Chemical investigations on the roots of ricinus communis resulted in the isolation and characterization of a novel flavonol glycoside, kaempferol 3-O-β-D-[6'''-O-acetylglucopyranosyl [1→3)-β-D-galactopyranoside] for which the trivial name ricinitin is proposed. The structure of ricinitin was established on the basis of chemical and spectroscopic techniques. Other flavonoids that have been identified include: quercetin 3-O-glucoside and quercetin 3-O-rhamnosylglucoside (rutin).
Publication DOI: 10.4314/bcse.v11i1.21013From the leaves of Byrsonima crassifolia four new glycolipids, 1,2-di-O-miristoyl-3-O-(6-sulpho-α-d-quinovopyranosyl)-glycerol, 1,2-di-O-(8-hexadecenoyl)-3-O-(6-sulpho-α-d-quinovopyranosyl)-glycerol, 1,2-di-O-palmitoyl-3-O-(β-d-glucopyranosyl)- glycerol and 1,2-di-O-(8-hexadecenoyl)-3-O-(β-d-glucopyranosyl)-glycerol, have been isolated. Nine known compounds were also found. The structures of new compounds were elucidated on the basis of chemical and spectral data.
glycolipids, leaves, Byrsonima crassifolia, Malpighiaceae, ‘nanche’, sulphonoglycolipids
Publication DOI: 10.1016/S0031-9422(96)00842-4An infusion of Persea americana leaves (Lauraceae) strongly inhibited herpes simplex virus type 1 (HSV-1), Aujeszky's disease virus (ADV) and adeno virus type 3 (AD3) in cell cultures. Its fractionation, guided by anti-HSV-1 and ADV assays, allowed the isolation and identification of two new flavonol monoglycosides, kaempferol and quercetin 3-O-alpha-D-arabinopyranosides, along with the known kaempferol 3-O-alpha-L-rhamnopyranoside (afzelin), quercetin 3-O-alpha-L-rhamnopyranoside (quercitrin), quercetin 3-O-beta-glucopyranoside and quercetin, The known quercetin 3-O-beta-galactopyranoside was identified in a mixture. Afzelin and quercetin 3-O-alpha-D-arabinopyranoside showed higher activity against acyclovir-resistant HSV-I, Chlorogenic add significantly inhibited the HSV-1 replication without any cytotoxicity. However, all the substances tested were less active than the infusion or fractions. The same substances did not affect ADV replication. Chemical structures were elucidated by the analysis of UV, H-1 and C-13 NMR data, mainly by APT, homo and heteronuclear COSY experiments. The configuration of the D-arabinose unit, not usual in natural plant products, was established on the basis of the optical rotation of the free sugar obtained after acid hydrolysis.
quercetin, leaves, quercitrin, Persea americana, kaempferol 3-o-alpha-d-arabinopyranoside, quercetin 3-o-alpha-d-arabinopyranoside, afzelin, quercetin 3-o-beta-glucopyranoside, quercetin 3-o-beta-galactopyranoside, chlorogenic acid, herpes simplex virus type 1, aujeszky's disease virus, adenovirus type 3
Publication DOI: 10.1002/(SICI)1099-1573(199812)12:8<562::AID-PTR356>3.0.CO;2-6The following flavonoid compounds have been isolated and identified from flowers of Urena lobata L.: kaempferol 3-O-(6-O-trans-p-coumaroyl)-β-glucoside (tiliroside), dihydrokaempferol 4'-O-β-glucopyranoside, kaempferol and quercetin 3-O-β-glucosides and 3-O-β-rutinosides also luteolin 4'-O-β-glucopyranoside. Their structures were established by conventional (acid, enzymatic and alkaline hydrolysis) and spectral analysis (UV, 1H NMR, 13C NMR). Chromatographical investigations indicated the presence of quercetin, kaempferol and kaempferol 7-O-glucoside.
flavonoid, quercetin, kaempferol, luteolin, Malvaceae, Urena lobata L., dihydrokaempferol glycosides, tiliroside
Journal NLM ID: 2985167RThe new flavonol glycosides quercetin 3-O-β-(2-O-α-L-rhamnopyranosyl)-glucopyranoside uronic acid and kaempferol 3-O-β-(2-O-α-L-rhamnopyranosyl)-glucopyranoside uronic acid were isolated from the leaves of Alchemilla speciosa Buser together with 13 known flavonol and flavone glycosides and (+)-catechin. The structures were determined by spectroscopic methods.
flavonol glycosides, Alchemilla speciosa, spectroscopic methods
NCBI PubMed ID: 17260291compositae, flavonoids, Plummera ambigens, patuletin-3-O-rutinoside, patuletin-3-O-galactoside, quercetin-3-O-glucoside
Publication DOI: 10.1016/S0031-9422(00)88567-2(3R)-O-β-D-Glucopyranosyloxy-5-phenylvaleric acid (1), (3R)-O-β-D-glucopyranosyloxy-5-phenylvaleric acid n-butyl ester (2), and a new dihydrochalcone diglycoside 4'-O-[β-D-glucopyranosyl-(1→-6)-glucopyranosyl]-oxy-2'-hydroxy-3',6'-dimethoxydihydrochalcone (3), together with six known flavonoid glycosides [kaempferol-3-O-β-D-glucopyranoside (= astragalin) (4), kaempferol-3-O-β-D-galactopyranoside (5), quercetin-3-O-β-D-glucopyranoside (= isoquercitrin) (6), quercetin-3-O-β-D-galactopyranoside (= hyperoside) (7), quercetin-3-O-(2'-O-galloyl)-β-D-glucopyranoside (8), and quercetin-3-O-β-D-glucuronopyranoside (9)] were isolated from the aerial parts of Polygonum salicifolium. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, ESI-MS, 1D- and 2D-NMR), chemical (methylation, enzymatic hydrolysis, partial synthesis), and chromatographic methods (HPLC, Chiralcel OD). The flavonoid glycosides (4-9) demonstrated scavenging properties toward the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC autographic assays.
isoquercitrin, hyperoside, flavonoid glycoside, phenylvaleric acid glycoside, Polygonum salicifolium, astragalin
NCBI PubMed ID: 10479312The aqueous EtOH extract of aerial parts of Eschscholtzia californica Cham. yielded six flavonol 3-O-glycosides including two new compounds: quercetin 3-O-[α-rhamnopyranosyl-(1-4)-α-rhamnopyranosyl-(1-6)-β-glucopyranoside] and isorhamnetin 3-O-[α-rhamnopyranosyl-(1-4)-α-rhamnopyranosyl-(1-6)-β-glucopyranoside]. Their structures were established on the basis of spectroscopic studies.
Eschscholtzia californica, Papaveraceae, flavonol 3-O-glycosides
NCBI PubMed ID: 9933948Two new dimeric hydrolyzable tannins named eumaculin A (1) and eusupinin A (2) have been isolated from Euphorbia maculata L. and Euphorbia supina RAFIN., and their structures elucidated. Twelve other polyphenolic compounds including five hydrolyzable tannins and five flavonol glycosides have also been isolated.
tannin, Euphorbiaceae, Euphorbia maculata, geraniin, dimeric hydrolyzable tannin, eumaculin A, eusupinin A, Euphorbia supina
Publication DOI: 10.1248/CPB.39.881Apples are important dietary sources of potentially healthy phenolics. In three successive seasons, the changes in concentrations of flavonoids and chlorogenic acid in the skin of two apple cultivars ‘Jonagold’ and ‘Elstar’ during and after regular (RS) and ultra low oxygen storage (ULO) at 1°C, were quantified by reversed-phase high performance liquid chromatography (RP-HPLC) with UV-VIS detector. There were no significant differences in the concentrations of flavonoids and chlorogenic acid between fruits stored under ULO and RS conditions. During storage of both ‘Jonagold’ (3, 6 and 8 months) and of ‘Elstar’ (2, 4 and 6 months), and during 1 or 2 weeks shelf life, the concentrations of cyanidin 3-galactoside and quercetin glycosides were relatively constant, while the concentrations of catechins, phloridzin and chlorogenic acid showed only minor changes. Exposing ‘Jonagold’ and ‘Elstar apples’ to white light during shelf life following storage increased the concentration of cyanidin 3-galactoside but not any of the other flavonoid classes. An explanation for this might be that the synthesis of different flavonoid classes may have different spectral sensitivity characteristics. It is concluded that flavonoids present in apples are stable and possibly not subject to net metabolic turnover during storage and shelf life.
phenolics, flavonoids, chlorogenic acid, storage condition, storage duration, quality
Publication DOI: 10.1016/S0925-5214(00)00116-2Variations in flavonoid and chlorogenic acid levels within fruit, within tree, between orchards, between cultivars and among mutants were characterised and quantified in ‘Elstar’ and ‘Jonagold’ apples by reversed-phase high performance liquid chromatography (RP-HPLC). The sun-exposed skin of individual fruit had much higher cyanidin 3-galactoside (anthocyanin) and quercetin 3-glycoside levels than the shaded skin, while phloridzin, catechins and chlorogenic acid were similar in the skin of both sides. Individual flavonoid and chlorogenic acid levels were not equally distributed within the fruit. Quercetin 3-glycosides and anthocyanin were almost exclusively found in the skin. Catechins were mostly found in the skin but some were present in the flesh. Phloridzin was most abundant in the seeds, with intermediate levels in both the core area and the skin, and the lowest level in the flesh. Chlorogenic acid was mainly present in the core area and the seeds with an intermediate level in the flesh and a low level in the skin. The levels of anthocyanin, quercetin 3-glycosides and total flavonoids were highest in fruit borne in the top of the tree followed by fruit from the outer tree parts, whereas the lowest levels were found in fruit from the inner tree. Terminal fruit contained the highest levels of these compounds, including catechins, compared to lateral and spur fruit. Phloridzin and chlorogenic acid were not affected by the position of the fruit in the tree nor by the bearing wood type. There were large differences in flavonoid and chlorogenic acid levels in ‘Elstar’ fruit between two normally productive orchards differing mainly in growth vigour. ‘Jonagold’ and its mutants had considerably higher levels of flavonoid and chlorogenic acid than ‘Elstar’ and its mutants. The most blushed mutants of both cultivars had higher levels of anthocyanin but not of flavonoids or chlorogenic acid compared to the standard cultivar and to the less blushed mutants. The most blushed mutants had a higher number of red cells per cell layer and more cell layers containing red cells than the standard cultivar and the less blushed mutants.
variation, flavonoids, apple, anthocyanin, chlorogenic acid
Publication DOI: 10.1016/S0304-4238(99)00124-7As a part of an investigation of the content of herbal drug preparations and herbal medicinal products, we have investigated tinctures (prepared with 40:60 and 60:40 (%,v/v) ethanolwater) of calendular flower, milk-thistle fruit, and passion flower, which are, respectively, widely used for their anti-inflammatory properties, to treat hepatic injuries, and to treat tension and difficulty falling asleep. The aim of this work was to evaluate the flavonoid content, because flavonoids are the active constituents or markers of these herbal drugs, and to establish the best solvent for the extraction of the constituents. The findings reported herein both confirm the presence of several flavonoids previously identified in these herbal drugs and report the presence of others not previously described and identified here for the first time. In general the flavonol content was highest in 60% tinctures. A rapid, reversed-phase (RP) HPLC assay was developed and validated and enabled good separation of all classes of flavonoids including flavones, flavonols, flavanonols, and flavanolignans. Aglycones and mono, di, and triglycosides (bothO-andC-derivatives) of the flavonoids are also easily and satisfactorily separated. This method is thus proposed for the analysis of other herbal drugs or herbal drug preparations in which flavonoids are the active constituents or markers.
mass spectrometry, thin-layer chromatography, column liquid chromatography, flavonoids and tinctures, calendula flower, milk-thistle fruit and passion flower
Publication DOI: 10.1007/BF02491573Eight varieties of lettuce (Lactuca sativum) and three varieties of endive (Cichorium endivia) were analyzed for flavonoid composition and content. Total flavonoid contents, expressed as units of aglycon for fresh material, were in the ranges of 0.3-229 μg/g for lettuce and 44-248 μg/g for endive. Five quercetin conjugates [quercetin 3-O-galactoside, quercetin 3-O-glucoside, quercetin 3-O-glucuronide, quercetin 3-O-(6-O-malonyl)glucoside, and quercetin 3-O-rhamnoside] and luteolin 7-O-glucuronide were measured in the green-leafed lettuce and an additional two cyanidin conjugates [cyanidin 3-O-glucoside and cyanidin 3-O-[(6-O-malonyl)glucoside]] in the red-leafed varieties. Three kaempferol conjugates [kaempferol 3-O-glucoside, kaempferol 3-O-glucuronide, and kaempferol 3-O-[6-O-malonyl)glucoside]] were measured in each of the endive varieties. The presence and identity of kaempferol 3-O-(6-O-malonyl)glucoside in endive was shown for the first time. Shredding of lettuce leaf followed by exposure to light produced significant losses of the flavonoid moiety in the green oak leaf (94%), red oak leaf (43%), iceberg (36%), green batavia (25%), lollo biondo (24%), and lollo rosso (6%) samples, whereas cos and green salad bowl samples did not show an overall loss. Shredding of endive also produced loss of the flavonoid moiety in escarole (32%), fine frisee (13%), and coarse frisee (8%). Significant demalonation was observed for both the quercetin and cyanidin glucosides in lettuce, whereas a similar degradation of the kaempferol analogue was found in endive tissue. Storage of whole heads of both lettuce and endive in the dark at 1 degrees C and 98% humidity for 7 days resulted in losses of total flavonol glycosides in the range of 7-46%. The identification of the amounts, position of substitution, and nature of the sugars is important for understanding the potential bioavailability and biological activities of flavonoids in salads.
HPLC, lettuce, flavonoid, endive, flavonoid conjugates
NCBI PubMed ID: 10995297The whole plant of Cotoneaster orbicularis contains the novel di-C-glycosylflavone, 4",4"'-di-O-β-glucopyranosyl-vicenin II, or 6,8-di-C-β-Cellobiosylapigenin, as well as the hitherto unknown natural phenolic glucoside, gentisic acid 2-O-β-glucopyranoside, or orbicularin. Further phenolics are protocatechuic, anisic, caffeic, p-coumaric acids, catechin, epicatechin, 2"-O-α-rhamnopyranosylvitexin, vitexin, rutin, isoquercetrin, hyperin and naringenin. All structures were determined by routine methods of analysis and confirmed mostly by 1H- and 13C-NMR.
NMR, ESI-MS, 6, rosaceae, whole plant, Cotoneaster orbicularis, C-glycosylЇavones, 8-di-C-cellobiosylapigenin, phenolic acid-O-glucoside, gentisic acid, 2-O-glucopyranoside, orbicularin
NCBI PubMed ID: 10746883Flavonoids are polyphenolic plant secondary metabolites with antioxidant and other biological activities potentially beneficial to health. Food-borne flavonoids occur mainly as glycosides, some of which can be absorbed in the human small intestine; however, the mechanism of uptake is uncertain. We used isolated preparations of rat small intestine to compare the uptake of the quercetin aglycone with that of some quercetin glucosides commonly found in foods, and investigated interactions between quercetin-3-glucoside and the intestinal hexose transport pathway. The nature of any metabolism of quercetin and its glucosides during small intestinal transport in vitro was determined by HPLC. The presence of quercetin-3-glucoside in the mucosal medium suppressed the uptake of labeled galactose by competitive inhibition and stimulated the efflux of preloaded galactose. Quercetin-3-glucoside and quercetin-4'-glucoside, but not quercetin-3,4'-diglucoside, were transported into everted sacs significantly more quickly than quercetin aglycone. Intact quercetin glucosides were not detected in mucosal tissue or within the serosal compartment, but both free quercetin and its metabolites were present, mainly as quercetin-3-glucuronide and quercetin-7-glucuronide. Evidently, quercetin derived from quercetin-3-glucoside passes across the small intestinal epithelium more rapidly than free quercetin aglycone. Monoglucosides of quercetin interact with the sodium-dependent glucose transporter. During passage across the epithelium, quercetin-3-glucoside is rapidly deglycosylated and then glucuronidated.
deglycosylation, quercetin glycosides, rat small intestine, sodium-dependent glucose transporter 1, flavonol uptake
NCBI PubMed ID: 11053519It is necessary to determine all of the phytochemical constituents of botanical extracts in order to ensure the reliability and repeatability of pharmacological and clinical research, to understand their bioactivities and possible side effects of active compounds and to enhance product quality control. HPLC chromatographic fingerprints can be applied for this kind of documentation. Combined HPLC-diode array detection-MS techniques can provide on-line UV and MS information for each peak in a chromatogram. In most cases, direct identification of the peaks is possible, based on comparison with published data or with standard compounds. This review will primarily focus on electrospray and thermospray ionization MS and their applications for the qualitative analyses of phenolic compounds, saponins, alkaloids and other classes of natural products in botanical extracts. Twenty-one of the most commonly used herbal examples, their phytochemical analyses and characteristics of their mass spectra are described.
alkaloids, saponins, plant materials, flavonoids, phenolic compounds, reviews
NCBI PubMed ID: 10890521Total flavonol and flavone contents of foods have been determined with validated state-of-the-art methods. Quercetin dominates, and flavonol levels found in vegetables and fruits are below 10 mg kg−1. However, high concentrations are found in onions (300 mg/kg), kale (450 mg/kg), broccoli (100 mg/kg), beans (50 mg/kg), apples (50 mg/kg), blackcurrants (40 mg/kg), and tea (30 mg/l). The dietary intake of flavonols varies 10-fold between countries (6–60 mg/day). Flavones are of minor importance in the diet. Tea, wine and fruits are the most important sources of flavanols, but there are gaps in our knowledge on flavanol levels of many foods. The absorption of dietary quercetin glycosides in humans ranges from 20 to 50%. The sugar moiety is an important determinant of the bioavailability of flavonols. The presence of a glucose moiety significantly enhances absorption. The extent of absorption of flavanols in humans seems similar to that of flavonols but has been little studied. Flavonols and flavanols are extensively metabolised, as only 1–2% of them are excreted with an intact flavonoid backbone. Hepatic biotransformations include glucuronidation and sulphatation of the phenolic hydroxyls and O-methylation of catechol groups. Bacteria of the colon cleave the C-ring of the flavonoid nucleus to phenolic acids which are subsequently absorbed. Apart from conjugates, virtually no metabolites have been characterised in humans. Absorption of flavanols is rather fast, with times to reach peak values between 0.5 and 4 h. Flavanols are rapidly excreted, with elimination half-lives of 1–6 h. Quercetin glycosides show rapid to slow absorption; peak values are reached between < 0.5 and 9 h. The type of glycoside determines the rate of absorption. Excretion of quercetin glycosides is slow: elimination half-lives are 24 h, independent of the type of glycoside. Analytical data for flavanols in foods are needed. Tea, as an important dietary source, has to be studied. Research on the bioavailability of flavonols and flavanols has to be expanded. Attention is needed for the identification and quantification of their metabolites in body fluids.
glycosides, bioavailability, flavones, flavonols, catechins, flavanols, food contents, dietary intake, absorption metabolism, phenolic acids
Publication DOI: 10.1002/(SICI)1097-0010(20000515)80:7<1081::AID-JSFA566>3.0.CO;2-GThe flowers of Albizzia julibrissin are used as a sedative in oriental traditional medicine. The phytochemical study of this plant allowed the isolation of two flavonol glycosides, quercitrin (1) and isoquercitrin (2). The sedative activity of these compounds was evaluated, and both compounds 1 and 2 increased pentobarbital-induced sleeping time in dose-dependent manner in mice. These results support the use of the flowers of this plant as a sedative agent.
flavonoids, Leguminosae, Albizzia julibrissin, sedative activity
NCBI PubMed ID: 10904180Atropine, camptothecin, cocaine, digitoxin, digoxin, morphine, pilocarpine, quinine, taxol, vinblastine and vincristine, among others, are important drugs obtained from higher plants and are used clinically. They have also served as lead compounds for the synthesis and modification of more effective and safer drugs, in many cases. In this chapter, drugs used as antimalarial compounds and for the complications of diabetes (aldose reductase and α-glucosidase inhibitors) will be discussed. Natural product chemists have isolated as little as 1.0 mg of pure compounds from natural sources and have been able to determine their structures using high resolution instrumental techniques. Organic chemists have synthesized thousands of compounds to produce one new drug on the basis of natural product leads, and pharmacologists and biochemists have tested their biological activity. Recently chemists and pharmacologists have worked together to develop techniques for studying structure-activity relationships using computer graphics and have designed new drugs. Biochemists, molecular biologists and pharmacologists have identified many receptors on which drugs act. Thus, mechanisms of drug action at the molecular level are being identified. From the accumulation of these results structure-activity relationships will lead to the preparation of thousands of useful compounds. We must produce drugs in these ways, because we cannot rely on solely on the limited amount of active compounds produced naturally in plants, in many cases, for a number of reasons. However we need to employ plant extracts themselves, because there are millions of people who cannot buy expensive synthetic drugs in the world and these extracts are widely used by them.
Publication DOI: 10.1016/S1572-5995(00)80025-3Red vine leaf extract (RVLE) is a herbal medicine containing several flavonoids, with quercetin-3-O-beta-glucuronide and isoquercitrin (quercetin-3-O-beta-glycoside) as the main components. Objective is to assess the efficacy and safety of once-daily doses of 360 and 720 mg RVLE (pharmaceutical extract code AS 195; Antistax Venenkapseln) compared to placebo in patients with stage I and incipient stage II chronic venous insufficiency (CVI). A 12-week, randomized, double-blind, placebo-controlled, parallel-group, multi-center study was done. Patients is male and female outpatients aged 25 to 75 years with stage I to stage II CVI (i.e. without extensive trophic changes), not having any other significant medical conditions and not treated with compression stockings, diuretics or other drugs affecting fluid balance. Patients were randomly assigned to a double-blind treatment with placebo, 360 mg AS 195 or 720 mg AS 195 once daily for 12 weeks, preceded and followed by a single-blind 2-week placebo treatment for baseline run-in and end-of-trial washout, respectively. Study criteria were evaluated at baseline, after 6 and 12 weeks of treatment and 2 weeks after discontinuation of treatment. Of the 260 patients enrolled and randomized, 219 completed the study in accordance with the protocol. In the intention-to-treat analysis (N = 257), the mean (+/- SD) lower leg volume (measured by water displacement plethysmography) of the patients treated with placebo (N = 87) increased by 15.2 +/- 90.1 g (displaced water mass) and by 33.7 +/- 96.1 g after 6 and 12 weeks compared to baseline. In contrast, for patients treated with AS 195, lower leg volume decreased, and after 12 weeks of treatment, the difference in mean lower leg volume between the active treatment groups and the placebo group was -75.9 g (95% CI: -106.1 to -45.8 g) and -99.9 g (95% CI: -130.3 to -69.6 g) for the group treated with 360-mg AS 195 (N = 86) and 720-mg AS 195 (N = 84), respectively. The changes in calf circumference showed a similar pattern: in patients treated with AS 195, both the higher dose (720 mg) and, albeit to a lesser extent, the lower dose (360 mg) resulted in a clear reduction in circumference over time, whereas, circumference remained largely unchanged in patients treated with the placebo (95% CI of the estimated treatment effects vs. placebo after 12 weeks: -1.40 to -0.56 cm and -1.73 to -0.88 cm for 360 and 720 mg AS 195, respectively). These differences were statistically significant (p < 0.001). The reductions in ankle circumference were qualitatively similar but quantitatively less marked. Subjectively, there was an improvement in key CVI symptoms (VAS) at 6 weeks with all treatments, but a further improvement at week 12 was seen only in the active treatment groups; at 12 weeks, the changes compared to baseline were significantly greater (p < 0.001) in both active treatment groups than in the placebo group. The treatments were well tolerated; Adverse events were rare and usually mild. Two adverse events (AEs) during treatment with the placebo led to hospitalization and were hence labeled as 'serious'. Three further patients were withdrawn because of AEs which occurred during treatment with the placebo. Once-daily doses of 360 and 720 mg AS 195 were confirmed to be safe and effective in the treatment of mild CVI, reducing significantly lower leg edema and circumference whilst improving key CVI-related symptoms to a clinically relevant extent. The edema reduction is at least equivalent to that reported for compression stockings and/or other edema-reducing agents. The higher dose was as well tolerated as the lower dose but resulted in a slightly greater and more sustained improvement.
flavonoids, Vitis vinifera, chronic venous insufficiency
NCBI PubMed ID: 10719612Five controversial species of Fallopia sect. Fallopia sensu Holub were examined for leaf flavonoid constituents. Twenty-one flavonoid compounds were isolated and identified; they were glycosylated derivatives of the flavonols kaempferol, quercetin, and myricetin, and of the flavones apigenin and luteolin. Among them, quercetin 3-O-galactoside and quercetin 3-O-glucoside were major flavonoid constituents and present in all species. Although the flavonoid data for some species are lacking, those available appear to be useful for species delimitation and for recognizing species relationships in the section. The flavonoid data, in conjunction with morphological evidence, strongly suggest that F. scandens, F. dentatoalata, F. dumetorum, and F. convolvulus are closely allied but distinct species. In addition, the flavonoid data for F. cilinodis lend additional support to the segregation of sect. Parogonum from sect. Fallopia.
chemotaxonomy, Polygonaceae, Fallopia sect. Fallopia, sect. Parogonum, leaf flavonoids
NCBI PubMed ID: 10725600Two flavonoids, quercetin-3-O-β-D-glucopyranoside (1) and quercetin-3,7-di-O-β-D-glucopyranoside (2), were isolated from the leaves of Mours alba (Moraceae). These two flavonoids exerted a significant inhibitory effect on the growth of the human promyelocytic leukemia cell line (HL-60) at the concentration of 0.2 mM. Compound 2 also induced differentiation of the HL-60 cell line to express CD 66b and CD 14 antigens. These flavonoids exhibited significant free radical scavenging effects on 1, 1-diphenyl-2-picyl-hydrazyl radical.
differentiation, flavonoid, mulberry leaf
NCBI PubMed ID: 10784426In previous studies, the qualitative and quantitative variation found in defense chemistry among birch populations and even among individual clones has been considerable. However, information about variation among adult, naturally regenerated birch trees from natural populations is still lacking. In this study, the phenolic composition of leaves of 30 naturally regenerated 20-year-old birch (Betula pendula) trees was analyzed for two successive years in order to characterize the chemical composition of individual trees, analyze the annual variation, and determine chemical similarities among individual trees within a population. The main phenolic compounds were flavonoid glycosides, myricetin, and quercetin derivatives. Annual variation in concentration among leaves was large. In most trees, concentrations were markedly higher in 1998 than in 1997; for certain compounds, the detected increase was as much as a 50%. However, for some individual trees, there were no differences between years in chemical quantity. Thus, when selection or grouping of trees is based on secondary chemistry, quantitative variation should be considered carefully. With the qualitative UPGMA method of classification, four chemotypes were found. The grouping was similar for both years, and qualitatively the results of an individual tree seem to be independent of sampling year. The stability in chemical profile of individual trees suggests that quality is tightly controlled by genotype, which provides a recognition tool for chemotaxonomy. The high within-population variation found in leaf defense chemistry may provide protection against different types of insects (generalists or specialists) and, thus, have positive effects on population survival.
variation, population, chemotype, phenolic compounds, birch, Betulaceae, Betula pendula
Publication DOI: 10.1023/A:1005582611863The isolation of flavonol glycosides 1-3 from the leaves of Ipomoea fistulosa is reported.
flavonols, Ipomoea fistulosa
NCBI PubMed ID: 10727823A benzophenone glucoside and two flavonol glycosides were isolated together with 27 known polyphenols from the aerial parts of Coleogyne ramosissima, and their structures were elucidated by spectroscopic and chemical methods as iriflophenone 2-O-β-glucopyranoside, isorhamnetin 3-O-2G-rhamnopyranosylrutinoside-7-O-α-rhamnopyranoside and limocitrin 3-O-rutinoside-7-O-β-glucopyranoside, respectively.
rosaceae, Coleogyne ramosissima, iriflophenone 2-O-glucopyranoside, isorhamnetin 3-O-2G-rhamnopyranosylrutinoside-7-O-rhamnopyranoside, limocitrin 3-O-rutinoside-7-O-glucopyranoside
NCBI PubMed ID: 10975504Three new flavonoid glycosides, together with 15 known flavonoids, have been isolated from the leaves of Eriobotrya japonica, and characterized as (2S)- and (2R)-naringenin 8-C-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosides, and cinchonain Id 7-O-β-D-glucopyranoside, respectively, based on spectral analyses including two dimensional (2D) NMR techniques. Higher proanthocyanidin fraction in the water-soluble portion of the extract was characterized as a procyanidin oligomer mixture mainly composed of undecameric procyanidin. These polyphenols have also been assessed for cytotoxic activity against two human oral tumor (human squamous cell carcinoma and human salivary gland tumor) cell lines. Selective cytotoxicity of the procyanidin oligomer between tumor and normal gingival fibroblast cells, and its possible mechanism, were also described.
Eriobotrya japonica, rosaceae, cinchonain Id 7-O-β-D-glucopyranoside, naringenin 8-C-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside, undecameric procyanidin, human oral tumor cell line
NCBI PubMed ID: 10823708The flavonoids of 11 species from six sections (Geranium, Batrachioides, Lucida, Unguiculata, Robertium, Erodioideae) of the genus Geranium have been studied. Quercetin and its derivatives were the most common aglycones with lesser amounts of kaempferol, myricetin and luteolin. Glycosylation was found mainly in the 3 or 4′ positions and to a lesser extent in the 7 position. Chemosystematic relationships are discussed. The occurrence of exudate flavonoids various methyl ether of kaempferol, quercetin and myricetin has been detected in all the 11 species surveyed.
flavonoid glycosides, chemosystematics, Geranium, flavonoid aglycones
Publication DOI: 10.1016/S0305-1978(99)00060-5Sixteen compounds were isolated from the aerial parts of Solanum incanum L. These compounds included ten flavonoids (1-10), chlorogenic acid (11), adenosine (12), benzyl-O-β-D-xylopyranosyl(1→2)-β-D-glucopyranoside (13), and three phenylalkanoic acids (14-16). The structures were determined from their physical and spectral data. Among these compounds, kaempferol 3-O-(6″′-O-2,5-dihydroxycinnamoyl)-β-D-glucopyranosyl (1→2) β-D-glucopyranoside (10) was identified as a new compound.
flavonoids, aerial parts, Solanum incanum L., ch1orogenic acid, miscellaneous compounds
Publication DOI: 10.1002/jccs.200000029High-performance liquid chromatography−electrospray ionization−mass spectrometry (LC-ESI-MS) was applied to the analysis of the flavonoids and their glycoside malonates of the flowers and leaves of red clover (Trifolium pratense). Through LC-MS comparative studies on the plant extracts and their malonate-free extracts, ∼20 flavonoid glycoside malonates were detected in the flower extract. Eight were identified as genistin 6‘‘-O-malonate (39), formononetin 7-O-β-D-glucoside 6‘‘-O-malonate (40), biochanin A 7-O-β-D-glucoside 6‘‘-O-malonate (41), trifoside 6‘‘-O-malonate (42), irilone 4‘-O-β-D-glucoside 6‘‘-O-malonate (43), pratensein 7-O-β-D-glucoside 6‘‘-O-malonate (44), isoquercitrin 6‘‘-O-malonate (45), and 3-methylquercetin 7-O-β-D-glucoside 6‘‘-O-malonate (46). About 15 other flavonoids and clovamides were proved to be present in this extract. The study also found that the flowers contained flavones as the major flavonoids, whereas the leaves had isoflavones as the major flavonoids. This is the first detection of the six malonates (39 and 42−46) in the extracts of red clover, and among them, 42, 43, and 46 are new compounds.
flavonoids, Leguminosae, Trifolium pratense, red clover, flavonoid glycoside malonates, clovamides, LC-ESI-MS analysis
NCBI PubMed ID: 10691640A RP-HPLC method with photodiode array detection and LC–electrospray ionization (ESI) MS confirmation was established for the determination of major active components in St. John’s Wort dietary supplement capsules. The samples alternatively were extracted with ethanol–acetone (2:3) using a 55°C water-bath shaker or an ambient temperature ultrasonic bath. Extracts were separated by RP-C18 chromatography using a 95-min water–methanol–acetonitrile–trifluoroacetic acid gradient. The major components were identified by photodiode array detection and then confirmed by LC–ESI-MS. The quantification of components was performed using an internal standard (luteolin). This method may serve as a valuable tool for the quality evaluation of St. John’s Wort dietary supplement products.
food analysis, flavonoids, St. John’s Wort, Hypericum peforatum, naphthodianthrones, phloroglucinols
NCBI PubMed ID: 10949475Quercetin is a typical flavonoid present mostly as glycosides in plant foods; it has attracted much attention for its potential beneficial effects in disease prevention. In this study, we examined human volunteers after the short-term ingestion of onion, a vegetable rich in quercetin glucosides. The subjects were served diets containing onion slices (quercetin equivalent: 67.6–93.6 mg/day) with meals for 1 wk. Quercetin was only found in glucuronidase-sulfatase-treated plasma, and its concentration after 10 h of fasting increased from 0.04 ± 0.04 μM before the trial to 0.63 ± 0.72 μM after the 1-wk trial. The quercetin content in low-density lipoprotein (LDL) after glucuronidase-sulfatase treatment corresponded to <1% of the α-tocopherol content. Human LDL isolated from the plasma after the trial showed little improvement of its resistance to copper ion-induced oxidation. It is therefore concluded that conjugated metabolites of quercetin accumulate exclusively in human blood plasma in the concentration range of 0.1 - 1 μM after the short-term ingestion of vegetables rich in quercetin glucosides, although these metabolites are hardly incorporated into plasma LDL.
quercetin metabolites; quercetin glycosides; low-density lipoprotein oxidation; glucuronidation
NCBI PubMed ID: 10938233A large number of flavonoids, mostly O-glycosides, are found in foods of plant origin. The bound sugar moiety is known to influence their bioavailability. We examined here the effect of the nature of the sugar on the absorption of the glycosides. Four groups of rats (n=6) received a meal containing 20 mg of quercetin equivalents supplied as aglycone, quercetin 3-glucoside, quercetin 3-rhamnoside or rutin. Plasma were hydrolysed by a βglucuronidase/sulfatase and analyzed by HPLC coupled to UV detection at 370 nm. Four hours after the beginning of the meal, the quercetin metabolites present in plasma were identical in all groups but their total concentrations were quite different. With pure quercetin the circulating levels were 11.7± 1.8 μM, but this level was three fold higher when quercetin was supplied as quercetin 3-glucoside (33.2± 3.5 μM). By contrast, the plasma concentrations of quercetin metabolites was quite low with the rutin meal (about 3 μM) and undetectable after the quercetin 3-rhamnoside meal. These data suggest that the 3-O-glucosylation improves the absorption of quercetin in the small intestine, whereas the binding of a rhamnose or of a glucose-rhamnose moiety to the aglycone markedly depressed its absorption. Additionnal experiments have shown that the higher plasma levels measured after the meal containing quercetin 3-glucoside compared to quercetin were maintained throughout a 24 hour period following the meal. In conclusion, the nature of the glycosylation markedly influences the efficiency of quercetin absorption in rats. Quercetin 3-glucose can be absorbed in the small intestine and is better absorbed than quercetin itself. By contrast, glycosides containing a rhamnose moiety could not be absorbed in the small intestine.
quercetin, quercetin glycosides, intestinal absorption, plasma metabolites
NCBI PubMed ID: 11216481Tyrosinase inhibitory and anti-tumor promoting activities of 14 compounds isolated from safflower and cotton oil cakes were evaluated together with the two genins of glycosides, trachorogenin (8a) and quercetin (12a). Catechin (11) and quercetin (12a) showed moderate tyrosinase inhibitory activity. N-(p-Coumaroyl)serotonin (1) and its 5-O-glucoside (3) exhibited weak anti-tyrosinase activity, but potent inhibitory activity on melanine production in the assay. Serotonin derivatives (1-4). 2-hydroxyarctiin (8), matairesinol glycoside (9) and sesquiterpene glucosides (13, 14) exhibited potent inhibitory activity on phorbol-12-myristate-13-acetate induced Epstein-Barr virus early antigen activation, which is the short term in vitro assay for anti-tumor-promoting activity.
Antioxidant, tyrosinase inhibitor, safflower oil cake, cotton oil cake, anti-tumor-promoter
Publication DOI: 10.1080/10575630008041225Different solvents used for extraction are characterized on the basis of the Snyder theory. The individual solvent strength (si) and selectivity values (sv) of the solvents are used to formulate an extraction strategy by use of selected solvents, in a manner similar to that used for the computer-aided HPLC and TLC “PRISMA” mobile phase optimization procedures. After a pre-assay using the nine proposed solvents, twelve measurements are necessary to obtain the global optimum. The new method allows successful solid-liquid extraction of compounds from biological matrices such as medicinal and aromatic plants. Data obtained from furocoumarin isomers and flavonoid glycosides extracted from different medicinal and aromatic plants are used to demonstrate the validity of the method. The structures and properties of the compounds to be extracted do not have to be known for the procedure to be used.
solid-liquid extraction, extraction strategy, solvent characterization, "PRISMA" system, phytopharmaceuticals
Publication DOI: 10.1007/BF02492820The antimicrobial activity of extracts of Geum rivale (Rosaceae) and that of some isolated constituents, on bacteria and fungi, was evaluated. The activity was concentrated in the triterpenes fraction and, for gram+ and gram- bacteria, also in the flavonoids fraction.
Geum rivale; Rosaceae; triterpenes; flavonoids; tannins; antimicrobial activity
NCBI PubMed ID: 11054853From the methanolic extract of leaves of Apocynum venetum L. var. basikurumon HARA, eight constituents were isolated and identified with respective authentic samples as succinic acid, chlorogenic acid, isoquercitrin, hyperoside, D-(-)-bornesitol, sucrose, β-sitosterol, and β-amyrin.
NCBI PubMed ID: 745047Flavonoids of 11 samples of Cercis, comprising seven species, were isolated and identified. Only 3-O-monoglycosides of kaempferol, quercetin and myricetin were obtained. Bauhinia (the largest genus in tribe Cercideae) is akin to Cercis because flavones are rarely found in the former. On the other hand, species of Bauhinia often present glycosides of isorhamnetin and a wider diversity of glycosides, and only rarely present myricetin. The frequent occurrence of this flavonol and the simpler flavonoid profile of Cercis may reflect a greater antiquity of Cercis as compared with Bauhinia. With the exception of C. canadensis var. mexicana, Cercis taxa from xerophytic habitats did not yield kaempferol glycosides in detectable amounts, as opposed to taxa from mesophytic habitats. The results obtained are consistent with proposals of merging C. reniformis into synonymy of C. occidentalis, as well as the recognition of two North American species, C. canadensis and C. occidentalis, and the recognition of the Asian C. gigantea.
Cercis; Cercideae; flavonoids; myricetin; chemotaxonomy
NCBI PubMed ID: 10793254Hypotheses are presented on the evolution of structural patterns of secondary metabolites (flavonoids and foliar wax alkanes) and fatty acids of families of "campos rupestres". The distribution of fatty acids is given for genera of Lythraceae, with emphasis on Cuphea (supposedly more advanced) and Diplusodon. Compounds with saturated short chains represent a derived condition in Lythraceae although they are probably restricted to Cuphea. It is suggested that evolution selected for more complex flavonoid patterns in Cuphea, with the inclusion of C-glycoflavones and methoxylated flavonols (rhamnetin and isorhamnetin), which are not found in members of Diplusodon and Lafoensia. The supposedly primitive groups of Eriocaulaceae (e.g., Paepalanthus) presented more complex flavonoid patterns characterized by flavones and flavonols, the latter frequently being 6-hydroxylated or methoxylated. More advanced groups of Eriocaulaceae (e.g., Leiothrix and Syngonanthus) apparently possess only flavones, C-glycoflavones are a salient feature of species with smaller habits. In Velloziaceae, members of the primitive subfamily Vellozioideae show distribution of alkanes of foliar epicuticular wax in which C27, C29 or C31 predominate; members of the derived subfamily Barbacenioideae usually show distributions with a predominance of C33 or C35, while species of Pleurostima (Barbacenioideae) have C31 as the main homologue, thus being intermediate between the two subfamilies. It is suggested that the evolution of alkanes in Velloziaceae follows a trend toward elongation of carbon chains. The condition of advanced or primitive chemical patterns is inferred from the results of cladistic analyses based on morphological characters (Eriocaulaceae and Lythraceae), and morphological and molecular characters (Velloziaceae).
flavonoids, flavonoid glycosides, Eriocaulaceae, Lythraceae, Velloziaceae
Publication DOI: 10.1590/S1415-47572000000400038The main dietary sources of polyphenols are reviewed, and the daily intake is calculated for a given diet containing some common fruits, vegetables and beverages. Phenolic acids account for about one third of the total intake and flavonoids account for the remaining two thirds. The most abundant flavonoids in the diet are flavanols (catechins plus proanthocyanidins), anthocyanins and their oxidation products. The main polyphenol dietary sources are fruit and beverages (fruit juice, wine, tea, coffee, chocolate and beer) and, to a lesser extent vegetables, dry legumes and cereals. The total intake is ∼1 g/d. Large uncertainties remain due to the lack of comprehensive data on the content of some of the main polyphenol classes in food. Bioavailability studies in humans are discussed. The maximum concentration in plasma rarely exceeds 1 μM after the consumption of 10–100 mg of a single phenolic compound. However, the total plasma phenol concentration is probably higher due to the presence of metabolites formed in the body's tissues or by the colonic microflora. These metabolites are still largely unknown and not accounted for. Both chemical and biochemical factors that affect the absorption and metabolism of polyphenols are reviewed, with particular emphasis on flavonoid glycosides. A better understanding of these factors is essential to explain the large variations in bioavailability observed among polyphenols and among individuals.
metabolism, flavonoid, Antioxidant, bioavailability, glucosidase, flavonoid glycoside, dietary intake, polyphenol, phenolic acid, gut absorption, colonic microflora
NCBI PubMed ID: 10917926In addition to rutin, quercetin 3-O-glucoside and quercetin 3-O-glucoside-7-O-rhamnoside, the methanolic extract of the aerial parts of Capparis spinosa yielded the new flavonoid quercetin 3-O-[6′″-α-l-rhamnosyl-6″-β-d-glucosyl]-β-d-glucoside (1).
Capparis spinosa; flavonoids
NCBI PubMed ID: 11449469Two new flavonol glycosides were isolated from Morettia philaena (Cruciferae) growing in Egypt together with four known compounds (kaempferol, quercetin, kaempferol 3-O-β-D-glucopyranoside, quercetin 3-O-β-D- glucopyranoside). Their structures were determined as quercetin 3-O-{2''- (6'''-p-cumaroyl-β-D-glucopyranosyl)- α-L-arabinopyranosyl}7''-O-β-D- glucopyranoside; kaempferol 3-O-{2''(6'''p-cumaroyl-β-D-glucopyranosyl)-α- L-arabinopyranosyl}7-O-β -D-glucopyranoside by spectroscopy and chemical methods.
flavonol glycoside, kaempferol glycoside, Cruciferae, quercetin glycoside, Morettia philaeana
Journal NLM ID: 9441222The aqueous ethanolic whole plant extract of Rosa arabica was found to contain the new natural dimeric phenolic compound, ellagic acid 3,3'-dimethyl ether 4−O−α−rhamnopyranoside, 9, along with ten known phenolic metabolites (1-8, 10 and 11). Structures of all compounds (1-11) were established by routine methods of analysis and confirmed by FAB-MS, 1H and 13C NMR spectral analysis.
NMR, FAB-MS, rosaceae, Rosa arabica, dimeric phenolic glycoside, ellagic acid 3, 3'-dimethyl ether 4−O−α−rhamnopyranoside
Journal NLM ID: 9714997Grape stems contain significant amounts of polyphenolic compounds, especially phenolic acids, flavonols, and flavanonols such as astilbin. The tannin content was characterized after the depolymerization reaction thiolysis. Tannins consisted of polymeric proanthocyanidins (up to 27 units) mainly consisting of (-)-epicatechin units along with smaller amounts of (+)-catechin, (-)-epicatechin gallate, and (-)-epigallocatechin. Flavanonols (astilbin) have been identified for the first time in stem and characterized by LC/MS and NMR. All phenolic compounds in grape stems were quantified by HPLC: quercetin 3-glucuronide was the most important, followed by catechin, caffeoyltartaric acid, and dihydroquercetin 3-rhamnoside (astilbin). Comparison was made of proanthocyanidin characteristics in different white and red grape varieties and also among parts of the cluster (skin, seed, and stem). Stem-condensed tannins were qualitatively intermediate between seed and skin but could not be differentiated between red and white varieties.
grape; stems; proanthocyanidins; flavanols; flavonols; flavanonols; phenolic acids
NCBI PubMed ID: 10775352Samples of Hyperici herba were obtained by harvesting Hypericum perforatum L. in different plant development stages. The relation of flower development phases in the drug's flower fraction was examined. The HPLC method was then employed for the analysis of the content of secondary metabolites in different flower ontogenesis phases. The content of dianthrones, derivatives of quercetin and hyperforin increased from the first bud phases (0.29 %, 0.80 %, and 2.47 %, respectively) to flowers just opened (1.04 %, 4.23 % and 6.60 %, respectively). The content of dianthrones and quercetin glycosides then decreased (in unripe fruits 0.11 % and 0.08 %, respectively), whereas the amounts of hyperforin increased to 8.07 % in fruits. The content of I3,II8-biapigenin increased from 0.21 % in small buds to 1.04 % in buds just before opening and has then decreased gradually to a value of 0.02 % in fruits. Rutin was not detected in the samples.
flavonoids, different parts of plant, Hypericum perforatum var. angustifolium, dianthrones, hyperforin
NCBI PubMed ID: 11199145Flavonoids and cinnamates are widespread phenolic secondary metabolites synthesized by plants for defensive purposes. Many foods and beverages contain high levels of phenolic compounds. Certain phenolics in the diet are particularly bioactive and have pronounced effects on mammalian cells. These effects, together with epidemiological studies and animal models, have led to the hypothesis that dietary phenolics contribute to the health benefits of a diet rich in fruit and vegetables. This paper examines the biochemistry of the uptake and metabolic route of two groups of plant phenolics, the flavonols and hydroxycinnamates.
metabolism, glycosidase, phenolic, chlorogenic acid, diet
NCBI PubMed ID: 10816092The leaves of Apocynum venetum L. are used as a tea material in north China and Japan. A water extract (500 mg/kg/day, one week administration) of the leaves of A. venetum showed protective effects against carbon tetrachloride (CCl4, 30 μl/mouse) or D-galactosamine (D-GalN, 700 mg/kg)/lipopolysaccharide (LPS, 20 μg/kg)-induced liver injury in mice. Tumor necrosis factor-α (TNF-α) secreted from LPS-stimulated macrophages is the most crucial mediator in the D-GalN/LPS-induced liver injury model. The extract had no significant inhibition on the increase of serum TNF-α (1169 ± 132 pg/ml vs. 1595 ± 314 pg/ml of control), but exhibited a complete inhibition at the concentration of 100 micrograms/ml on TNF-α (100 ng/ml)-induced cell death in D-GalN (0.5 mM)-sensitized mouse hepatocytes. Further activity-guided fractionation resulted in the isolation of fifteen flavonoids viz. (-)-epicatechin (1), (-)-epigallocatechin (2), isoquercetin (3), hyperin (4), (+)-catechin (5), (+)-gallocatechin (6), kaempferol-6'-O-acetate (7), isoquercetin-6'-O-acetate (8), catechin-[8,7-e]-4 α-(3,4-dihydroxpyhenyl)-dihydro-2(3H)-pyranone (9), apocynin B (10), apocynin A (11), cinchonain Ia (12), apocynin C (13), apocynin D (14) and quercetin (15). All the compounds showed inhibitory effects on TNF-α-induced cell death with different intensities. The flavonol glycosides 3, 4, 7 and 8 and the phenylpropanoid-substituted flavan-3-ols 11 and 12 showed potent inhibitory effects on TNF-α-induced cell death with IC50 values of 37.5, 14.5, 31.2, 55.1, 71.9 and 41.2 μM, respectively. In contrast, the clinically used 5 and its analogues 1, 2 and 6 showed apparent activity only at 80 microM. These flavonoids appeared to be the hepatoprotective principles of the leaves of A. venetum. The hepatoprotective effects exhibited by the extract and its constituents suggest a validation of the leaves as a tea material.
hepatoprotective activity, liver injury, Apocynum venetum
NCBI PubMed ID: 10763585Spartium junceum L. (Fabaceae) flowers are used for the treatment of peptic ulcers in Turkish folk medicine. The possible superoxide dismutase-like activity of the extracts, fractions and constituents obtained through activity-guided fractionation were studied by using in vitro electron spin resonance spectrometry, in order to explain the role of antioxidant principles in the potent antiulcerogenic activity of the extract. Despite the fact that the triterpene, spartitrioside, which was previously reported as the active antiulcerogenic constituent of the flowers was found almost inactive, the flavonoid-rich fractions showed potent antioxidant activity. Five flavonoid glycosides bearing catechol structure in ring B were isolated from the butanol extract and their structures were elucidated using 1H- and 13C-NMR techniques as isoquercitrin (quercetin 3β-glucoside) (1,); luteolin 4’β-glucoside (2); quercetin 3, 4′-diglucoside (3); azaleatin 3β-glucoside (quercetin 5-methylether 3β-glucoside) (4), quercetin 4′β-glucoside (5). Flavonoids (2) and (4) showed the highest in vitro antioxidant activity with 22.59 and 19.08 U/ml, respectively.
electron spin resonance; Spartium junceum; antioxidant activity; superoxide dismutase-like activity; spin trapping; superoxide radical
NCBI PubMed ID: 110910013-O-Rhamnopyranosylisorhamnetin, 3-O-glucopyranosylisorhamnetin, 7-O-galactopyranosylluteolin, quercitrin, isoquercitrin, wistin, and a novel isoflavonoid, 3′-hydroxy-6,4′-dimethoxy-7-O-β-D-glucopyranosylisoflavone, were isolated from the aerial parts of Caragana alaica. Of these, the previously described compounds were identified on the basis of their physicochemical and spectral characteristics, whereas the spectral analysis and conversion to a known compound, cladrastin, allowed the structural elucidation of the novel isoflavone glycoside.
Caragana alaica, 3′-hydroxy-6, 4′-dimethoxy-7-O-β-D-glucopyranosylisoflavone, 3-O-rhamnopyranosylisorhamnetin, 3-O-glucopyranosylisorhamnetin, 7-O-galactopyranosylluteolin
NCBI PubMed ID: 11696899| b-D-Galp-(1-3)-Quercetin | Show graphically |
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Structure type: monomer
Trivial name: hyperoside, hyperin, hyperoside, hyperin, baohuoside-II, quercetin 3-galactoside, vulgarsaponin B
Compound class: saponin glycoside, glycoside, flavonoid glycoside, flavonol glycoside, flavone glycoside, flavanone glycoside
Contained glycoepitopes: IEDB_136044,IEDB_137472,IEDB_141794,IEDB_190606,SB_165,SB_166,SB_187,SB_195,SB_7,SB_88
The present investigation was carried out to know the aboriginal usage of Morchella esculenta L. as an ethnomedicinal food by tribals of Kashmir, an extreme northern state of India for curing of arthritis, osteoporosis, general bone weakness and cure child labour pain and post menopause pain of women. The average long-life expectancy (~80 years) and delayed aging ensured the abundant use of M. esculenta L. as the bases of their daily foods as well as their traditional medicine. The antioxidant character of this mushroom was carried out by chemical and electrochemical assays. The chemical assay was done by DPPH, nitric- oxide, super-oxide scavenging and reducing power while as, electrochemical assay was done by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) using multi-wall carbon nanotube paste electrode (MWCNTPE) at 0.02 M acetate buffer (pH 4.5). The phenolic profiling of the mushroom was evaluated through Folin–Ciocalteu reagent using gallic acid/ascorbic acid as standard which were qualified and quantified by HPLC-UV technique, respectively. The IC50 values found were 57.02 µg/ml, 58.02 µg/ml and 40.01 µg/ml for DPPH, nitric-oxide and superoxide. The electrochemical results have shown one oxidation potential at 1.12 V and positive potential at 1.119±0.01 V in CV and 1.19 V in DPV. DPV at superoxide radical scavenging level of mushroom at dropping mercury electrode (DME) in 0.1 M KCl, produced a reduction peak potential at −0.160 V. HPLC-UV have confirmed the presence of eight phenolic compounds namely, p-coumaric acid, tocopherol, catechol, rutin, hyperoside, quercetin, ellagic acid and cinnamic acid with quercetin at highest percentage (169.76%).
Antioxidant, Morchella esculenta, electrochemical, phenolic compounds
Publication DOI: 10.1007/s11694-019-00099-3A novel flavonol glycoside, rouhuoside [l], was isolated from aerial parts of Epimedium pubescens along with six known flavonol glycosides. Structures were established by spectroscopic and chemical methods. The structure of rouhuoside [l] was elucidated as 8-prenylkaempferol-3-O-α-L-rhamnopyranosyl-(4→1)-β-D-glucopyranosyl-7-O-β-D-glucopyranoside. The known compounds were identified as epimedoside C, icariside I, icariin, baohuoside VI, hyperin, and baohuoside I
rouhuoside, flavonol glycoside, Epimedium pubescens
Publication DOI: 10.1021/np50071a030A new 9,10-dihydrophenanthrene derivative named epimedoicarisoside A was isolated from the aerial parts of Epimedium koreanum along with ten known flavonoids. The structure of this compound was determined on the basis of spectral analysis (FAB-Mass spectrometry, 1H-1H COSY, 13C COSY, DEPT, and 13C long range COSY, etc.) as 2-hydroxy-3,4,6,7-tetramethoxy-9,10-dihydrophenanthrene-2-O-β-D-glucopyranoside. The known compounds were identified as icariin, epimedoside C, icarisid I, baohuoside I, diphylloside A, baohuoside II, 2″-O-rhamnosylicarisid II, sagittatoside A, hyperoside and icaritin-3-O-rhamnopyranoside.
flavonoids, Epimedium koreanum, Berberidaceae, 9, 10-dihydrophenanthrene derivate, epimedoicarisoside A, icariin, epimedoside C, icarisid I, baohuoside I, diphylloside A, baohuoside II, 2″-O-rhamnosylicarisid II, sagittatoside A, hyperoside, icaritin-3-O-rhamnopyranoside
Publication DOI: 10.1016/0031-9422(94)00926-KFlavonols were characterized and measured in experimental (n = 46) and commercial (n = 9) red raspberry juices by HPLC/diode array spectral techniques. Samples were prepared using minicolumns, packed with Polyamide 6. A fraction eluted with methanol contained eight or fewer quercetin glycosides, quercetin, and kaempferol. A second fraction eluted subsequently with 0.5% ammonia in methanol contained three flavonol glucuronides, two flavonol forms, aglycons, ellagic acid, and its derivatives. Quercetin 3-glucuronide was the major flavonol in experimental and commercial juices, respectively (mean of 54 and 51 ppm), and a flavonol presumed to be quercetin 3-sophoroside was the second primary compound (means of 29 and 33 ppm). In addition, 36 flavonol forms were measured in trace amounts. The mean total concentrations of quercetin and kaempferol forms, respectively, in experimental juices (n = 45) were 118 and 3.6 ppm and in commercial juices (n = 7) 121 and 3.4 ppm, respectively. The mean total flavonol concentrations in experimental and commercial juices were 122 and 125 ppm, respectively. Influences of cultivar (n = l0), processing method (standard, high-speed centrifugation, depectinization, diffusion extraction, vacuum and osmotic concentration) and environmental factors (geographic origin, maturity, harvesting method, mold contamination) were evaluated.
Publication DOI: 10.1021/jf00035a025A new flavonol glycoside, rhamnocitrin 3-O-β-D-galactopyranoside, has been isolated from aerial parts of Anthyllis onobrychioides, together with the known 3-O-β-D-galactopyranosides of quercetin, isorhamnetin and kaempferol.
structure elucidation, flavonoids, flavonol glycosides, Leguminosae, Anthyllis onobrychioides
Publication DOI: 10.1016/S0031-9422(00)83076-9A novel flavonol glycoside was isolated from the aerial parts of Epimedium wushanense along with nine known flavonols; icariin, baohuoside-VI, rouhuoside, quercetin 3-galactoside and 3-rhamnoside, epimedoside-A, icaritin, baohuoside-I and baohuoside-II. Their structures were established by spectroscopic methods. The new compound was elucidated as 8-prenylkaempferol-4′-methylether-3-[xylosyl(1→4)rhamnoside]-7-glucoside.
13C, FABMS, 5, 3, 1H NMR, Berberidaceae, Epimedium wushanense, 7-trihydroxy-4′-methoxy-8-prenylflavone-3-[xylosyl(1→4)rhamnoside]-7-glucoside, prenylated flavonol glycosides
Publication DOI: 10.1016/0031-9422(90)80206-VFrom the leaf of Rhodedrndron ellipticum β-carotene, sitosterol, uvaol, quercetin, myricetin, quercitrin, myricitrin, hyperin, quercetin 3-glucoside, and the new aglycone quercetin 5,4′-dimethyl ether were characterized by spectroscopic analysis and/or comparison with authentic samples.
quercetin, Rhododendron ellipticum, qricaceae, myricetin, quercitrin, myricitrin, hyperin, quercetin 3-glucoside, quercetin 5, 4′-dimethyl ether
Publication DOI: 10.1016/0031-9422(94)00905-9Two new flavonol glucosides, viz. quarcetin 3′,4′-dimethyl ether 7-glucoside and tamarixetin 3,7-bis-glucoside, together with hyperin, quercetin, quercitrin, foeniculin, isorhamnetin 7-glucoside, rutin, 3,5,6-trihydroxy-7,4′-dimethoxyflavone, arbutin, sitosterol β-glucoside, l-sesamin and palmitic acid were isolated from the pericarps of Zanthoxylum bungeanum. Their structures were established by spectroscopic and spectrophotometric methods.
pericarp, Zanthoxylum bungeanum, flavonol glycosides, Rutaceae, quercetin 3′, 4′-dimethyl ether 7-glucoside, tamarixetin 3, 7-bis-glucoside
Publication DOI: 10.1016/0031-9422(94)00965-VSeveral plants collected through different approaches were screened on distinct receptors using ligand-binding studies as bioassay. Extracts of Microtea debilis showed high activity on adenosine A(1) receptors. Bioassay-guided fractionation using ligand-binding studies resulted in the isolation of an adenosine A(1) active ligand, cirsimarin (cirsimaritin 4'-O-glucoside). GTP did not influence the radioligand inhibition curve of cirsimarin, indicating that this compound is acting as an antagonist at the adenosine-A(1) receptors. The use of this plant against ''proteinuria'' in traditional medicine in Suriname (South America) may be explained by the adenosine A(1) antagonistic action of cirsimarin. A series of flavonoids was tested in the same assay, but they were less active. No structure-activity relationship could be observed.
NCBI PubMed ID: 9214739Further investigation of the leaves of Acanthopanax divaricatus gave two analogues of chiisanoside, which is a lupane triterpenoid oligoglycosyl ester. The structures were established as 28-O-α-l-rhamnopyranosyl(1→4)-β-d-glucopyranosyl(1→6)β-d-glucopyranosyl esters of 1β,11α-dihydroxy-3-oxo-lup-20(29)-en-28-oic acid and 1(R),11α,22α-trihydroxy-3,4-seco-lupa-4(23),20(29)-diene-3,28-dioic acid 3,11α-lactone based on chemical and spectroscopic evidence. in biosynthetic terms, one is the precursor of chiisanoside and the other is an oxygenated derivative chiisanoside.
araliaceae, triterpenoid saponin, Acanthopanax divaricatus, lupane glycoside, chiisanoside, isochiisanoside, protochiisanoside, 22α-hydroxychiisanoside
Publication DOI: 10.1016/S0031-9422(97)00017-4From the leaves of Byrsonima crassifolia four new glycolipids, 1,2-di-O-miristoyl-3-O-(6-sulpho-α-d-quinovopyranosyl)-glycerol, 1,2-di-O-(8-hexadecenoyl)-3-O-(6-sulpho-α-d-quinovopyranosyl)-glycerol, 1,2-di-O-palmitoyl-3-O-(β-d-glucopyranosyl)- glycerol and 1,2-di-O-(8-hexadecenoyl)-3-O-(β-d-glucopyranosyl)-glycerol, have been isolated. Nine known compounds were also found. The structures of new compounds were elucidated on the basis of chemical and spectral data.
glycolipids, leaves, Byrsonima crassifolia, Malpighiaceae, ‘nanche’, sulphonoglycolipids
Publication DOI: 10.1016/S0031-9422(96)00842-4A new flavonol glycoside, quercetin 3-galactosyl(1→2)rhamnoside, has been isolated from the leaves of Embelia schimperi. The known compounds quercetin 3-rutinoside, quercetin 3-rhamnoside, quercetin 3-galactoside, myricetin and quercetin were also identified from this plant.
structural elucidation, Myrsinaceae, Embelia schimperi, quercetin 3-galactosyl(1→2)rhamnoside
Publication DOI: 10.1016/S0031-9422(96)00706-6AIM: To find the chemical constituents of Prunella vulgaris L. METHODS: To separate the constituents of Prunella vulgaris by using various kinds of chromatography and identify their structures on the basis of spectral analysis. RESULTS: Six compounds were isolated from the spikes of Prunella vulgaris L. Their structures were established as 3β,16α,24-trihydroxyoleana-12-en-28-oic acid-3-O-(6′-butyryl)-β-D-glucopyranosid (I), ursolic acid (II), 2α,3α-dihydroxyurs-12-en-28-oic acid (III), quercetin (IV), quercetin-3-O-β-D-galactoside (V) and ethyl caffeate (VI) based on the analysis of spectral data of IR, UV FAB-MS, 1D and 2D-NMR. CONCLUSION: I was a new compound, named vulgarsaponin B, III was isolated for the first time from this plant, V and VI for the first time from the Prunella genus.
triterpenoid saponin, Labiate, Prunella vulgaris, vulgarsaponin B
Journal NLM ID: 21710340RSeven compounds have been isolated from methanol extracts of whole Saxifraga stellaris (Saxifragaceae) plants. They were identified as the new compound, 6-O-galloyl fructose, together with 3-O-[2-O-(β-D-xylopyranosyl)-β-D-galactopyranosyl]-kaempferol, 3-O-[2-O-(β-D-xylopyranosyl)-β-D-galactopyranosyl]-quercetin, trifolin, hyperin, resveratrol-3-O-glucoside, triandrin, by chemical and spectroscopic methods. Their free radical scavenging properties are also described.
fructose, flavonoid glycosides, free radical scavengers, Saxifragaceae, Saxifraga stellaris, stilbene glycoside, 6-O-galloyl, triandrin
Publication DOI: 10.1016/S0031-9422(98)00496-8The new flavonol glycosides quercetin 3-O-β-(2-O-α-L-rhamnopyranosyl)-glucopyranoside uronic acid and kaempferol 3-O-β-(2-O-α-L-rhamnopyranosyl)-glucopyranoside uronic acid were isolated from the leaves of Alchemilla speciosa Buser together with 13 known flavonol and flavone glycosides and (+)-catechin. The structures were determined by spectroscopic methods.
flavonol glycosides, Alchemilla speciosa, spectroscopic methods
NCBI PubMed ID: 17260291(3R)-O-β-D-Glucopyranosyloxy-5-phenylvaleric acid (1), (3R)-O-β-D-glucopyranosyloxy-5-phenylvaleric acid n-butyl ester (2), and a new dihydrochalcone diglycoside 4'-O-[β-D-glucopyranosyl-(1→-6)-glucopyranosyl]-oxy-2'-hydroxy-3',6'-dimethoxydihydrochalcone (3), together with six known flavonoid glycosides [kaempferol-3-O-β-D-glucopyranoside (= astragalin) (4), kaempferol-3-O-β-D-galactopyranoside (5), quercetin-3-O-β-D-glucopyranoside (= isoquercitrin) (6), quercetin-3-O-β-D-galactopyranoside (= hyperoside) (7), quercetin-3-O-(2'-O-galloyl)-β-D-glucopyranoside (8), and quercetin-3-O-β-D-glucuronopyranoside (9)] were isolated from the aerial parts of Polygonum salicifolium. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, ESI-MS, 1D- and 2D-NMR), chemical (methylation, enzymatic hydrolysis, partial synthesis), and chromatographic methods (HPLC, Chiralcel OD). The flavonoid glycosides (4-9) demonstrated scavenging properties toward the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC autographic assays.
isoquercitrin, hyperoside, flavonoid glycoside, phenylvaleric acid glycoside, Polygonum salicifolium, astragalin
NCBI PubMed ID: 10479312Apples are important dietary sources of potentially healthy phenolics. In three successive seasons, the changes in concentrations of flavonoids and chlorogenic acid in the skin of two apple cultivars ‘Jonagold’ and ‘Elstar’ during and after regular (RS) and ultra low oxygen storage (ULO) at 1°C, were quantified by reversed-phase high performance liquid chromatography (RP-HPLC) with UV-VIS detector. There were no significant differences in the concentrations of flavonoids and chlorogenic acid between fruits stored under ULO and RS conditions. During storage of both ‘Jonagold’ (3, 6 and 8 months) and of ‘Elstar’ (2, 4 and 6 months), and during 1 or 2 weeks shelf life, the concentrations of cyanidin 3-galactoside and quercetin glycosides were relatively constant, while the concentrations of catechins, phloridzin and chlorogenic acid showed only minor changes. Exposing ‘Jonagold’ and ‘Elstar apples’ to white light during shelf life following storage increased the concentration of cyanidin 3-galactoside but not any of the other flavonoid classes. An explanation for this might be that the synthesis of different flavonoid classes may have different spectral sensitivity characteristics. It is concluded that flavonoids present in apples are stable and possibly not subject to net metabolic turnover during storage and shelf life.
phenolics, flavonoids, chlorogenic acid, storage condition, storage duration, quality
Publication DOI: 10.1016/S0925-5214(00)00116-2Variations in flavonoid and chlorogenic acid levels within fruit, within tree, between orchards, between cultivars and among mutants were characterised and quantified in ‘Elstar’ and ‘Jonagold’ apples by reversed-phase high performance liquid chromatography (RP-HPLC). The sun-exposed skin of individual fruit had much higher cyanidin 3-galactoside (anthocyanin) and quercetin 3-glycoside levels than the shaded skin, while phloridzin, catechins and chlorogenic acid were similar in the skin of both sides. Individual flavonoid and chlorogenic acid levels were not equally distributed within the fruit. Quercetin 3-glycosides and anthocyanin were almost exclusively found in the skin. Catechins were mostly found in the skin but some were present in the flesh. Phloridzin was most abundant in the seeds, with intermediate levels in both the core area and the skin, and the lowest level in the flesh. Chlorogenic acid was mainly present in the core area and the seeds with an intermediate level in the flesh and a low level in the skin. The levels of anthocyanin, quercetin 3-glycosides and total flavonoids were highest in fruit borne in the top of the tree followed by fruit from the outer tree parts, whereas the lowest levels were found in fruit from the inner tree. Terminal fruit contained the highest levels of these compounds, including catechins, compared to lateral and spur fruit. Phloridzin and chlorogenic acid were not affected by the position of the fruit in the tree nor by the bearing wood type. There were large differences in flavonoid and chlorogenic acid levels in ‘Elstar’ fruit between two normally productive orchards differing mainly in growth vigour. ‘Jonagold’ and its mutants had considerably higher levels of flavonoid and chlorogenic acid than ‘Elstar’ and its mutants. The most blushed mutants of both cultivars had higher levels of anthocyanin but not of flavonoids or chlorogenic acid compared to the standard cultivar and to the less blushed mutants. The most blushed mutants had a higher number of red cells per cell layer and more cell layers containing red cells than the standard cultivar and the less blushed mutants.
variation, flavonoids, apple, anthocyanin, chlorogenic acid
Publication DOI: 10.1016/S0304-4238(99)00124-7Components were separated by means of solvent extraction and chromatography on Toyopeal and Sephadex LH20, the structures were determined by spectral analysis and chemical evidences. Five compounds were obtained and elucidated as methyl-3-O-(β-D-glucopyranosyl)-gallate (I), methyl-3-O-[β-D-(6′-O-galloyl)-glucopyranosyl]-gallate (II), quercetin 3-O-β-D-galactopyranoside (III), myricetin 3-O-β-D-galactopyranoside (IV), myricetin 3-O-α-L-rhamnopyranoside (V). These compounds were separated from this plant for the first time, where I and II were new natural products.
quercetin, myricetin, Geranium dahuricum DC, methyl gallate
Journal NLM ID: 21710340REight varieties of lettuce (Lactuca sativum) and three varieties of endive (Cichorium endivia) were analyzed for flavonoid composition and content. Total flavonoid contents, expressed as units of aglycon for fresh material, were in the ranges of 0.3-229 μg/g for lettuce and 44-248 μg/g for endive. Five quercetin conjugates [quercetin 3-O-galactoside, quercetin 3-O-glucoside, quercetin 3-O-glucuronide, quercetin 3-O-(6-O-malonyl)glucoside, and quercetin 3-O-rhamnoside] and luteolin 7-O-glucuronide were measured in the green-leafed lettuce and an additional two cyanidin conjugates [cyanidin 3-O-glucoside and cyanidin 3-O-[(6-O-malonyl)glucoside]] in the red-leafed varieties. Three kaempferol conjugates [kaempferol 3-O-glucoside, kaempferol 3-O-glucuronide, and kaempferol 3-O-[6-O-malonyl)glucoside]] were measured in each of the endive varieties. The presence and identity of kaempferol 3-O-(6-O-malonyl)glucoside in endive was shown for the first time. Shredding of lettuce leaf followed by exposure to light produced significant losses of the flavonoid moiety in the green oak leaf (94%), red oak leaf (43%), iceberg (36%), green batavia (25%), lollo biondo (24%), and lollo rosso (6%) samples, whereas cos and green salad bowl samples did not show an overall loss. Shredding of endive also produced loss of the flavonoid moiety in escarole (32%), fine frisee (13%), and coarse frisee (8%). Significant demalonation was observed for both the quercetin and cyanidin glucosides in lettuce, whereas a similar degradation of the kaempferol analogue was found in endive tissue. Storage of whole heads of both lettuce and endive in the dark at 1 degrees C and 98% humidity for 7 days resulted in losses of total flavonol glycosides in the range of 7-46%. The identification of the amounts, position of substitution, and nature of the sugars is important for understanding the potential bioavailability and biological activities of flavonoids in salads.
HPLC, lettuce, flavonoid, endive, flavonoid conjugates
NCBI PubMed ID: 10995297The whole plant of Cotoneaster orbicularis contains the novel di-C-glycosylflavone, 4",4"'-di-O-β-glucopyranosyl-vicenin II, or 6,8-di-C-β-Cellobiosylapigenin, as well as the hitherto unknown natural phenolic glucoside, gentisic acid 2-O-β-glucopyranoside, or orbicularin. Further phenolics are protocatechuic, anisic, caffeic, p-coumaric acids, catechin, epicatechin, 2"-O-α-rhamnopyranosylvitexin, vitexin, rutin, isoquercetrin, hyperin and naringenin. All structures were determined by routine methods of analysis and confirmed mostly by 1H- and 13C-NMR.
NMR, ESI-MS, 6, rosaceae, whole plant, Cotoneaster orbicularis, C-glycosylЇavones, 8-di-C-cellobiosylapigenin, phenolic acid-O-glucoside, gentisic acid, 2-O-glucopyranoside, orbicularin
NCBI PubMed ID: 10746883White clover flowers (Trifolium repens L.) contain an abundance of phenolics, namely cis- and trans-p-coumaric acid 4-O-β-D-glucopyranoside, the 3-O-β-D-galactopyranosides of myricetin, quercetin and kaempferol together with two new derivatives namely myricetin 3-O-(6"-acetyl)-β-D-galactopyranoside and kaempferol 3-O-(6"-acetyl)-β-D-galactopyranoside. Gallocatechin, epigallocatechin, gallocatechin-(4α-8)-epigallocatechin and their corresponding prodelphinidin polymers were also present. The 13C-NMR spectra showed that the polymers consisted of only gallocatechin and epigallocatechin monomeric units with the latter being about twice as abundant in the extenders but only slightly more than that in the terminating units. The average degree of polymerization was estimated by 13C-NMR and ES-MS, which gave a remarkably consistent result of about 5.8 flavanol units.
phenolics, Leguminosae, flowers, Trifolium repens, prodelphinidins, molecular size
NCBI PubMed ID: 10939359It is necessary to determine all of the phytochemical constituents of botanical extracts in order to ensure the reliability and repeatability of pharmacological and clinical research, to understand their bioactivities and possible side effects of active compounds and to enhance product quality control. HPLC chromatographic fingerprints can be applied for this kind of documentation. Combined HPLC-diode array detection-MS techniques can provide on-line UV and MS information for each peak in a chromatogram. In most cases, direct identification of the peaks is possible, based on comparison with published data or with standard compounds. This review will primarily focus on electrospray and thermospray ionization MS and their applications for the qualitative analyses of phenolic compounds, saponins, alkaloids and other classes of natural products in botanical extracts. Twenty-one of the most commonly used herbal examples, their phytochemical analyses and characteristics of their mass spectra are described.
alkaloids, saponins, plant materials, flavonoids, phenolic compounds, reviews
NCBI PubMed ID: 10890521Total flavonol and flavone contents of foods have been determined with validated state-of-the-art methods. Quercetin dominates, and flavonol levels found in vegetables and fruits are below 10 mg kg−1. However, high concentrations are found in onions (300 mg/kg), kale (450 mg/kg), broccoli (100 mg/kg), beans (50 mg/kg), apples (50 mg/kg), blackcurrants (40 mg/kg), and tea (30 mg/l). The dietary intake of flavonols varies 10-fold between countries (6–60 mg/day). Flavones are of minor importance in the diet. Tea, wine and fruits are the most important sources of flavanols, but there are gaps in our knowledge on flavanol levels of many foods. The absorption of dietary quercetin glycosides in humans ranges from 20 to 50%. The sugar moiety is an important determinant of the bioavailability of flavonols. The presence of a glucose moiety significantly enhances absorption. The extent of absorption of flavanols in humans seems similar to that of flavonols but has been little studied. Flavonols and flavanols are extensively metabolised, as only 1–2% of them are excreted with an intact flavonoid backbone. Hepatic biotransformations include glucuronidation and sulphatation of the phenolic hydroxyls and O-methylation of catechol groups. Bacteria of the colon cleave the C-ring of the flavonoid nucleus to phenolic acids which are subsequently absorbed. Apart from conjugates, virtually no metabolites have been characterised in humans. Absorption of flavanols is rather fast, with times to reach peak values between 0.5 and 4 h. Flavanols are rapidly excreted, with elimination half-lives of 1–6 h. Quercetin glycosides show rapid to slow absorption; peak values are reached between < 0.5 and 9 h. The type of glycoside determines the rate of absorption. Excretion of quercetin glycosides is slow: elimination half-lives are 24 h, independent of the type of glycoside. Analytical data for flavanols in foods are needed. Tea, as an important dietary source, has to be studied. Research on the bioavailability of flavonols and flavanols has to be expanded. Attention is needed for the identification and quantification of their metabolites in body fluids.
glycosides, bioavailability, flavones, flavonols, catechins, flavanols, food contents, dietary intake, absorption metabolism, phenolic acids
Publication DOI: 10.1002/(SICI)1097-0010(20000515)80:7<1081::AID-JSFA566>3.0.CO;2-GFive controversial species of Fallopia sect. Fallopia sensu Holub were examined for leaf flavonoid constituents. Twenty-one flavonoid compounds were isolated and identified; they were glycosylated derivatives of the flavonols kaempferol, quercetin, and myricetin, and of the flavones apigenin and luteolin. Among them, quercetin 3-O-galactoside and quercetin 3-O-glucoside were major flavonoid constituents and present in all species. Although the flavonoid data for some species are lacking, those available appear to be useful for species delimitation and for recognizing species relationships in the section. The flavonoid data, in conjunction with morphological evidence, strongly suggest that F. scandens, F. dentatoalata, F. dumetorum, and F. convolvulus are closely allied but distinct species. In addition, the flavonoid data for F. cilinodis lend additional support to the segregation of sect. Parogonum from sect. Fallopia.
chemotaxonomy, Polygonaceae, Fallopia sect. Fallopia, sect. Parogonum, leaf flavonoids
NCBI PubMed ID: 10725600The extract of Crataegus, a mixture of flavonoids and procyanidins extracted from hawthorn, Crataegus oxyacantha, L. and C. monogyna Jacq., relaxed vascular tone or increased production of cyclic GMP in the rat aorta, but flavonoid components of Crataegus extract, hyperoside, rutin and vitexin, did not affect the vascular tone. The aim of the present study was to characterize the endothelium-dependent relaxation elicited by procyanidins fractionated from Crataegus extract in isolated rat aorta. Procyanidins caused endothelium-dependent relaxation which was associated with the production of cyclic GMP. Both responses to these procyanidins were inhibited by methylene blue or N(G)-nitro-L-arginine, but not by indomethacin. Relaxation in response to procyanidins was not affected by atropine, diphenhydramine, [D-Pro2,D-Trp7,9]substance P, propranolol, nifedipine, verapamil and glibenclamide, but were markedly reduced by tetraethylammonium. These findings showed that procyanidins in Crataegus extract may be responsible for the endothelium-dependent nitric oxide-mediated relaxation in isolated rat aorta, possibly via activation of tetraethylammonium-sensitive K+ channels.
nitric oxide, procyanidins, aorta, vascular relaxation, cyclic GMP, K+ channels
NCBI PubMed ID: 10901280Three bisdesmosidic saponins, 20-hydroxyecdysone, and quercetin-3-O-β-D-galactoside were isolated from the methanol extract of the aerial parts of Achyranthes aspera L. (Amaranthaceae). Their structures were established on the basis of NMR spectroscopic analysis; the complete 1H and 13C assignments of the compounds were achieved by means of 2D NMR studies.
NMR spectroscopy, structure elucidation, natural products, saponins
Publication DOI: 10.1007/PL00010306In previous studies, the qualitative and quantitative variation found in defense chemistry among birch populations and even among individual clones has been considerable. However, information about variation among adult, naturally regenerated birch trees from natural populations is still lacking. In this study, the phenolic composition of leaves of 30 naturally regenerated 20-year-old birch (Betula pendula) trees was analyzed for two successive years in order to characterize the chemical composition of individual trees, analyze the annual variation, and determine chemical similarities among individual trees within a population. The main phenolic compounds were flavonoid glycosides, myricetin, and quercetin derivatives. Annual variation in concentration among leaves was large. In most trees, concentrations were markedly higher in 1998 than in 1997; for certain compounds, the detected increase was as much as a 50%. However, for some individual trees, there were no differences between years in chemical quantity. Thus, when selection or grouping of trees is based on secondary chemistry, quantitative variation should be considered carefully. With the qualitative UPGMA method of classification, four chemotypes were found. The grouping was similar for both years, and qualitatively the results of an individual tree seem to be independent of sampling year. The stability in chemical profile of individual trees suggests that quality is tightly controlled by genotype, which provides a recognition tool for chemotaxonomy. The high within-population variation found in leaf defense chemistry may provide protection against different types of insects (generalists or specialists) and, thus, have positive effects on population survival.
variation, population, chemotype, phenolic compounds, birch, Betulaceae, Betula pendula
Publication DOI: 10.1023/A:1005582611863The isolation of flavonol glycosides 1-3 from the leaves of Ipomoea fistulosa is reported.
flavonols, Ipomoea fistulosa
NCBI PubMed ID: 10727823From the dried leaves of Alangium chinense, five novel phenolic glycosides, 6‘-O-galloylsalicin (1); 4‘,6‘-di-O-galloylsalicin (2); 4‘,6‘-O-(S)-hexahydroxydiphenoylsalicin (3); 4‘,6‘-O-(R)-hexahydroxydiphenoylsalicin (4); and pyrocatechol 1-O-β-d-xylopyranosyl(1→6)-β-d-glucopyranoside (5) were isolated. The structures of these new compounds were determined by spectroscopic methods.
phenolic glycosides, gallic acid, Alangium chinense, salicins
NCBI PubMed ID: 10650086The flavonoids of 11 species from six sections (Geranium, Batrachioides, Lucida, Unguiculata, Robertium, Erodioideae) of the genus Geranium have been studied. Quercetin and its derivatives were the most common aglycones with lesser amounts of kaempferol, myricetin and luteolin. Glycosylation was found mainly in the 3 or 4′ positions and to a lesser extent in the 7 position. Chemosystematic relationships are discussed. The occurrence of exudate flavonoids various methyl ether of kaempferol, quercetin and myricetin has been detected in all the 11 species surveyed.
flavonoid glycosides, chemosystematics, Geranium, flavonoid aglycones
Publication DOI: 10.1016/S0305-1978(99)00060-5Two chalcone glycosides were isolated, together with seven known flavonol glycosides, from the leaves of Asarum canadense. The structures of the chalcone glycosides were established as chalcononaringenin 2',4'-di-O-glucoside and chalcononaringenin 2'-O-glucoside-4'-O-gentiobioside by chemical, UV, FAB MS, 1H and 13C NMR evidence.
Aristolochiaceae, Asarum canadense, chalcononaringenin 2', 4'-di-O-glucoside, chalcononaringenin 2'-O-glucoside-4'-O-gentiobioside
NCBI PubMed ID: 11140534High-performance liquid chromatography−electrospray ionization−mass spectrometry (LC-ESI-MS) was applied to the analysis of the flavonoids and their glycoside malonates of the flowers and leaves of red clover (Trifolium pratense). Through LC-MS comparative studies on the plant extracts and their malonate-free extracts, ∼20 flavonoid glycoside malonates were detected in the flower extract. Eight were identified as genistin 6‘‘-O-malonate (39), formononetin 7-O-β-D-glucoside 6‘‘-O-malonate (40), biochanin A 7-O-β-D-glucoside 6‘‘-O-malonate (41), trifoside 6‘‘-O-malonate (42), irilone 4‘-O-β-D-glucoside 6‘‘-O-malonate (43), pratensein 7-O-β-D-glucoside 6‘‘-O-malonate (44), isoquercitrin 6‘‘-O-malonate (45), and 3-methylquercetin 7-O-β-D-glucoside 6‘‘-O-malonate (46). About 15 other flavonoids and clovamides were proved to be present in this extract. The study also found that the flowers contained flavones as the major flavonoids, whereas the leaves had isoflavones as the major flavonoids. This is the first detection of the six malonates (39 and 42−46) in the extracts of red clover, and among them, 42, 43, and 46 are new compounds.
flavonoids, Leguminosae, Trifolium pratense, red clover, flavonoid glycoside malonates, clovamides, LC-ESI-MS analysis
NCBI PubMed ID: 10691640A RP-HPLC method with photodiode array detection and LC–electrospray ionization (ESI) MS confirmation was established for the determination of major active components in St. John’s Wort dietary supplement capsules. The samples alternatively were extracted with ethanol–acetone (2:3) using a 55°C water-bath shaker or an ambient temperature ultrasonic bath. Extracts were separated by RP-C18 chromatography using a 95-min water–methanol–acetonitrile–trifluoroacetic acid gradient. The major components were identified by photodiode array detection and then confirmed by LC–ESI-MS. The quantification of components was performed using an internal standard (luteolin). This method may serve as a valuable tool for the quality evaluation of St. John’s Wort dietary supplement products.
food analysis, flavonoids, St. John’s Wort, Hypericum peforatum, naphthodianthrones, phloroglucinols
NCBI PubMed ID: 10949475The aqueous and ethanol extracts from the leaves of Gochnatia polymorpha and further fractions obtained from the latter extract using solvents with increasing polarity, including its aqueous residue and the amino acid, 4-hydroxy-N-methyl-proline were investigated by carrageenin-induced pedal oedema formation. It was shown that the aqueous and ethanol extracts and the ethyl acetate fraction demonstrated significant antiinflammatory activity. The chemical investigation of the latter fraction revealed the presence of caffeic acid, chlorogenic acid, 3-0-methylquercetin, hyperosid and rutin. The amino acid 4-hydroxy-N-methyl-proline, a nonprotein amino acid that has not been reported before in the Asteraceae was isolated as a major compound and identified by spectroscopic methods.
Gochnatia polymorpha; antiinflammatory activity; flavonoids; 4-hydroxy-N-methyl-proline
NCBI PubMed ID: 11114003Different solvents used for extraction are characterized on the basis of the Snyder theory. The individual solvent strength (si) and selectivity values (sv) of the solvents are used to formulate an extraction strategy by use of selected solvents, in a manner similar to that used for the computer-aided HPLC and TLC “PRISMA” mobile phase optimization procedures. After a pre-assay using the nine proposed solvents, twelve measurements are necessary to obtain the global optimum. The new method allows successful solid-liquid extraction of compounds from biological matrices such as medicinal and aromatic plants. Data obtained from furocoumarin isomers and flavonoid glycosides extracted from different medicinal and aromatic plants are used to demonstrate the validity of the method. The structures and properties of the compounds to be extracted do not have to be known for the procedure to be used.
solid-liquid extraction, extraction strategy, solvent characterization, "PRISMA" system, phytopharmaceuticals
Publication DOI: 10.1007/BF02492820From the methanolic extract of leaves of Apocynum venetum L. var. basikurumon HARA, eight constituents were isolated and identified with respective authentic samples as succinic acid, chlorogenic acid, isoquercitrin, hyperoside, D-(-)-bornesitol, sucrose, β-sitosterol, and β-amyrin.
NCBI PubMed ID: 745047Flavonoids of 11 samples of Cercis, comprising seven species, were isolated and identified. Only 3-O-monoglycosides of kaempferol, quercetin and myricetin were obtained. Bauhinia (the largest genus in tribe Cercideae) is akin to Cercis because flavones are rarely found in the former. On the other hand, species of Bauhinia often present glycosides of isorhamnetin and a wider diversity of glycosides, and only rarely present myricetin. The frequent occurrence of this flavonol and the simpler flavonoid profile of Cercis may reflect a greater antiquity of Cercis as compared with Bauhinia. With the exception of C. canadensis var. mexicana, Cercis taxa from xerophytic habitats did not yield kaempferol glycosides in detectable amounts, as opposed to taxa from mesophytic habitats. The results obtained are consistent with proposals of merging C. reniformis into synonymy of C. occidentalis, as well as the recognition of two North American species, C. canadensis and C. occidentalis, and the recognition of the Asian C. gigantea.
Cercis; Cercideae; flavonoids; myricetin; chemotaxonomy
NCBI PubMed ID: 10793254The photostabilities of luteolin, in solution, in the presence of aluminium ions, and deposited on a cellulosic substrate have been determined and compared with those of quercetin and other 5-hydroxyflavonols and their 3-O-glycosides. In aqueous methanol solution, luteolin and flavonol 3-glycosides exhibited no degradation over periods of up to 15 h of UV irradiation. However, the flavonols studied were all found to degrade and their relative photostabilities correlate with their redox potentials. Quercetin was the least stable. In the presence of aluminium ions, all the flavonoids, including luteolin, were degraded by UV irradiation. In contrast to the absorption spectra in dilute solution, the reflectance spectra of both quercetin and luteolin deposited on a cellulosic substrate exhibited strong absorptions beyond 400 nm. On this substrate these flavonoids displayed the characteristic yellow colour associated with flavonoids in some environments. Although the quercetin yellow faded rapidly on exposure to UV radiation, the colour of luteolin darkened. This was due to the formation of a photoproduct absorbing maximally at 450 nm. The relevance of these observations to cellulosic dyeing and flower colouration are discussed.
5-hydroxyflavones; flavonols; luteolin; quercetin
Publication DOI: 10.1016/S1010-6030(00)00320-8The aqueous ethanolic whole plant extract of Rosa arabica was found to contain the new natural dimeric phenolic compound, ellagic acid 3,3'-dimethyl ether 4−O−α−rhamnopyranoside, 9, along with ten known phenolic metabolites (1-8, 10 and 11). Structures of all compounds (1-11) were established by routine methods of analysis and confirmed by FAB-MS, 1H and 13C NMR spectral analysis.
NMR, FAB-MS, rosaceae, Rosa arabica, dimeric phenolic glycoside, ellagic acid 3, 3'-dimethyl ether 4−O−α−rhamnopyranoside
Journal NLM ID: 9714997The leaves of Argania spinosa from Morocco were investigated for flavonoids and condensed tannins. Four flavonol glycosides were identified by 1H NMR as myricitrin, quercitrin, hyperoside and myricetin 3-O-galactoside. UV spectrophotometric and histochemical methods were carried out to quantify and locate flavonoids and condensed tannins from leaves, stems and thorns of A. spinosa. Both high content and cell localisation of total polyphenols could explain the Argan tree adaptation to aridity.
flavonol glycosides, Sapotaceae, condensed tannins, Argania spinosa, histochemistry
Publication DOI: 10.1080/12538078.2000.10515843Samples of Hyperici herba were obtained by harvesting Hypericum perforatum L. in different plant development stages. The relation of flower development phases in the drug's flower fraction was examined. The HPLC method was then employed for the analysis of the content of secondary metabolites in different flower ontogenesis phases. The content of dianthrones, derivatives of quercetin and hyperforin increased from the first bud phases (0.29 %, 0.80 %, and 2.47 %, respectively) to flowers just opened (1.04 %, 4.23 % and 6.60 %, respectively). The content of dianthrones and quercetin glycosides then decreased (in unripe fruits 0.11 % and 0.08 %, respectively), whereas the amounts of hyperforin increased to 8.07 % in fruits. The content of I3,II8-biapigenin increased from 0.21 % in small buds to 1.04 % in buds just before opening and has then decreased gradually to a value of 0.02 % in fruits. Rutin was not detected in the samples.
flavonoids, different parts of plant, Hypericum perforatum var. angustifolium, dianthrones, hyperforin
NCBI PubMed ID: 11199145The leaves of Apocynum venetum L. are used as a tea material in north China and Japan. A water extract (500 mg/kg/day, one week administration) of the leaves of A. venetum showed protective effects against carbon tetrachloride (CCl4, 30 μl/mouse) or D-galactosamine (D-GalN, 700 mg/kg)/lipopolysaccharide (LPS, 20 μg/kg)-induced liver injury in mice. Tumor necrosis factor-α (TNF-α) secreted from LPS-stimulated macrophages is the most crucial mediator in the D-GalN/LPS-induced liver injury model. The extract had no significant inhibition on the increase of serum TNF-α (1169 ± 132 pg/ml vs. 1595 ± 314 pg/ml of control), but exhibited a complete inhibition at the concentration of 100 micrograms/ml on TNF-α (100 ng/ml)-induced cell death in D-GalN (0.5 mM)-sensitized mouse hepatocytes. Further activity-guided fractionation resulted in the isolation of fifteen flavonoids viz. (-)-epicatechin (1), (-)-epigallocatechin (2), isoquercetin (3), hyperin (4), (+)-catechin (5), (+)-gallocatechin (6), kaempferol-6'-O-acetate (7), isoquercetin-6'-O-acetate (8), catechin-[8,7-e]-4 α-(3,4-dihydroxpyhenyl)-dihydro-2(3H)-pyranone (9), apocynin B (10), apocynin A (11), cinchonain Ia (12), apocynin C (13), apocynin D (14) and quercetin (15). All the compounds showed inhibitory effects on TNF-α-induced cell death with different intensities. The flavonol glycosides 3, 4, 7 and 8 and the phenylpropanoid-substituted flavan-3-ols 11 and 12 showed potent inhibitory effects on TNF-α-induced cell death with IC50 values of 37.5, 14.5, 31.2, 55.1, 71.9 and 41.2 μM, respectively. In contrast, the clinically used 5 and its analogues 1, 2 and 6 showed apparent activity only at 80 microM. These flavonoids appeared to be the hepatoprotective principles of the leaves of A. venetum. The hepatoprotective effects exhibited by the extract and its constituents suggest a validation of the leaves as a tea material.
hepatoprotective activity, liver injury, Apocynum venetum
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