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Found 1 structure.
Displayed structure 1
| a-L-Rhap-(1-6)-b-D-Glcp-(1-3)-Quercetin | Show graphically |
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Structure type: oligomer
C27H30O16
Trivial name: rutin, rutoside, rutin, quercetin rutinoside, rutoside, quercetin 3-O-rutinose, quercetin-3-O-rutinoside, quercetin 3-O-rutinoside
Compound class: saponin glycoside, glycoside, flavonoid glycoside, flavonol glycoside, flavone glycoside
Contained glycoepitopes: IEDB_136105,IEDB_142488,IEDB_144144,IEDB_146664,IEDB_225177,IEDB_885823,IEDB_983931,SB_192
Aegle marmelos, a well-known Indian plant with medicinal and religious importance, has been extensively used in Indian traditional medicine. The present study aimed to isolate, identify, and evaluate the biological activities of endophytic fungi from A. marmelos. One of the isolates, labeled as L7, was identified as Aspergillus flavus using morphology and ITS gene sequence. Total phenolic and flavonoid contents in the culture filtrate were found to be 65.77 mg GAE/ml and 158.33 mg quercetin/ml of crude extract, respectively. The extract showed excellent antimicrobial activity against common human bacterial and fungal pathogens. The test extract at 700 µg/ml, which notably reduced the concentration of DPPH-free radical as percent DPPH scavenging activity, was found to be the highest (64.53 %). The extract, at the concentration of 2 mg/ml, produced 70 % inhibition of hemolysis of RBCs compared to 78 % produced by standard drug (Ibuprofen). Chemical profiling of the fermented extract using TLC followed by UV and FTIR revealed the presence of flavonoids. The HPLC analysis confirmed the presence of bioflavonoid rutin in the extract. To the best of our knowledge, this is the first report on production of bioactive flavonoid by endophytic Aspergillus flavus obtained from A. marmelos and its pharmaceutical potential. In conclusion, the endophytic Aspergillus flavus obtained from the A. marmelos could be explored as an economic and potential natural resource with diverse pharmaceutical and biological activities
endophytic fungus, Aspergillus flavus, Aegle marmelos, rutin
NCBI PubMed ID: 25860867Endophytes are microorganisms that colonize the interior of host plants without causing apparent disease. They have been widely studied for their ability to modulate relationships between plants and biotic/abiotic stresses, often producing valuable secondary metabolites that can affect host physiology. Owing to the advantages of microbial fermentation over plant/cell cultivation and chemical synthesis, endophytic fungi have received significant attention as a mean for secondary metabolite production. This article summarizes currently reported results on plant-endophyte interaction hypotheses and highlights the biotechnological applications of endophytic fungi and their metabolites in agriculture, environment, biomedicine, energy, and biocatalysts. Current bottlenecks in industrial development and commercial applications as well as possible solutions are also discussed.
endophyte, biocontrol, mutualism, interaction benefit, adversity tolerance, nutrient acquisition, bioproduct
NCBI PubMed ID: 29808328Here we determined the phenolic compounds and antioxidant, antimicrobial, genotoxic, and anticancer potential of edible mushrooms Craterellus cornucopioides. The phytochemical analysis was evaluated using high-performance liquid chromatography. Antioxidant activity was evaluated by free radical scavenging, superoxide anion scavenging, and reducing power. Craterellus cornucopioides extract had potent antioxidant activity. Further, the antimicrobial potential was determined by a microdilution method, where minimum inhibitory concentration values ranged from 0.1 to 10 mg/mL. Genotoxic potential was determined by cytokinesis block micronucleus test. The separate treatment did not show genotoxic effect, whereas the combined treatment with mitomycin C significantly reduced the micronuclei frequency in a dose-dependent manner. The highest concentration significantly reduced nuclear division index in comparison to untreated human peripheral blood lymphocytes, whereas in combined treatment, the extract did not significantly affect this parameter. Finally, the cytotoxic activity was tested using microculture tetrazolium test where measured IC50 values ranged from 65.5 to 131.7 μg/mL.
HPLC, antimicrobial, Antioxidant, cytotoxic, genotoxic, mushroom extract
Publication DOI: 10.1177/1934578X19843610The 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/s11694-019-00099-3This study was projected to assess the structure-based docking studies of monoamine oxidase against bioactive compounds from Trametes pubescens fruiting body extract in the treatment of neurodegenerative diseases. In this study, five bioactive compounds were acknowledged monoamine oxidase inhibitors acquired from T. pubescens fruiting body extract which were retrieved by the PubChem database. Molecular docking investigations in addition to ADME studies were carried out using different bioinformatics tools. The findings demonstrated that epigallocatechin gallate (-11.770 kcal/mol), caffeic acid (-7.010 kcal/mol) and gallic acid (-6.984 kcal/mol) have the highest molecular docking scores than the coligand used (zonisamide) (-6.328 kcal/mol). Whereas, naringin (-4.514 kcal/mol) and rutin hydrate (-3.833 kcal/mol) have the lowest molecular binding scores when compared to the coligand. However, only gallic and caffeic acids have good ADME results and compared favourably with the coligand. Hence, it can be deduced from this study that gallic and caffeic acids can function as a possible therapeutic agent in the treatment of neurodegenerative diseases better than zonisamide (coligand).
zonisamide, molecular binding score, ADME, coligand
Journal NLM ID: 101266394Three dihydroflavonol glycosides, 3-O-α-L-rhamnosides of (2S,3S)-, (2R,3R)- and (2R,3S)-5,7,3',4'-tetrahydroxydihydroflavonol, were isolated from Sphaerostephanos arbuscula as the first example of dihydroflavonols from ferns. Aglycone chirality was determined by 1H-NMR data.
1H-NMR, astilbin, Sphaerostephanos arbuscula, dihydroflavonol, chirality determination, fern
Publication DOI: 10.1248/cpb.43.338The 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)89642-9A new flavonol glycoside, camelliaside C, was isolated from "tea seed cake" prepared from the defatted seeds of Camellia sinensis O. KUNTZE. The structure was determined as kaempferol 3-O-β-D-galactopyranosyl-(1→2)-β-D-glucopyranoside by spectroscopic methods (FAB-MS, UV, IR, ^1H- and ^<13>C-NMR) and the enzymatic transformation of camelliaside C to astragalin. Camelliaside C showed an inhibitory effect on the arachidonate 5-lipoxygenase of RBL-1 cells (IC_<50> : 1.4×10^<-4> M) as did camelliaside A and B isolated from the same product.
Camellia sinensis, Theaceae, camelliaside C, arachidonate 5-lipoxygenase inhibitor, tea seed cake
Journal NLM ID: 0377775This 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-PFrom the aerial parts of Prunus prostrata (Rosaceae), the following new compounds were isolated: 5-(b-D-glucopyranosyloxy)-2-(3-hydroxybutyl)-l,3,3-trimethylcyclohexene [1], 4-(b-D-glucopyranosyloxy)-3-(3-methyl-2-butenyl)benzoic acid [2], fraxinol 6-b-D-galactopyranoside [3], and 6,7-dihydroxy-5-methoxycoumarin 6-b-D-glucopyranoside [4]. Their structures were established by means of fabms and a combination of homo- and hetero-nuclear 2D nmr techniques. Twelve known compounds, never previously isolated from this genus, were also found in this plant.
Publication DOI: 10.1021/np50102a017From 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: 7766391Two 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-VPoisonous plants are a serious problem for cattle breeding in Latin America. Owing to the extensive pastural agriculture it is not possible to exterminate such plants. Apart from the considerable financial loss to individual farmers and the national economy owing to dead animals, there is the important question of how far the meat and milk of chronically poisoned animals are a health risk for humans. The toxins of the most important toxic plants from Brazil are described.
NCBI PubMed ID: 8153954Two 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.v11i1.21013Several 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: 9214739Two novel acylated flavonol glycosides, along with iridoids, triterpenes, steroids and a-tocopherolquinone, were iso lated from the leaves of Alibertia sessilis (Rubiaceae). The determination of the structures of the new compounds was based mainly on 1H- and 13C-NMR.
terpenoids, Rubiaceae, Iridoids, Alibertia sessilis, cylated flavonol glycosides, α-tocopherolquinone
Journal NLM ID: 101511356A 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)00706-6glycoside, extract, rutin, Juniperus oxycedrus
Publication DOI: 10.1016/S0031-6865(97)00037-XThe 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: 17260291The 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: 9933948An activity directed fractionation of a 50% aqueous ethanol extract of A. wilkesiana and A. hispida leaves resulted in the isolation of gallic acid, corilagin and geraniin as the compounds responsible for the observed antimicrobial activity. Quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside were also isolated from the inactive fraction of A. hispida. The structures were established by permethylation, 2D - NMR ((1)H and (13)C) and MS data.
antimicrobial, Acalypha wilkesiana, Acalypha hispida, corilagin, geraniin
NCBI PubMed ID: 10925407Water-soluble derivatives of rutin, a very common glycoside of quercetin (=3,3′,4′,5,7-pentahydroxyflavone=2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one) and a potent plant antioxidant from the flavonol family, were synthesized by simple chemical procedures aimed at introducing carboxy or sulfo groups at the sugar moiety (Scheme 1). Such derivatives form stable molecular complexes with malvin, a polyphenolic pigment from the anthocyanin family, and thereby prove to be very effective in the enhancement (hyperchromism) and variation (bathochromism) of natural colours. The H2O-solubilizing carboxylate and sulfate groups are shown to deeply modify the enthalpy-entropy balance of the pigment-flavonol complexation (copigmentation). A molecular interpretation of the complexation-induced bathochromic shift in the pigment VIS band is proposed. Finally, the H2O-soluble rutin derivatives are shown to retain the high antioxidant ability of rutin as evidenced by their efficient trapping of the coloured radical DPPH (=2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl).
chemical synthesis, derivatives, rutin, malvin, natural pigments
Publication DOI: 10.1002/(SICI)1522-2675(20000216)83:2<428::AID-HLCA428>3.0.CO;2-JDioxins invade the body mainly through the diet, and produce toxicity through the transformation of aryl hydrocarbon receptor (AhR). An inhibitor of the transformation should therefore protect against the toxicity and ideally be part of the diet. We examined flavonoids ubiquitously expressed in plant foods as one of the best candidates, and found that the subclasses flavones and flavonols suppressed antagonistically the transformation of AhR induced by 1 nM of 2,3,7,8-tetrachlorodibenzo-p-dioxin, without exhibiting agonistic effects that transform AhR. The antagonistic IC(50) values ranged from 0.14 to 10 μM, close to the physiological levels in human.
flavonoid, cancer prevention, dioxin antagonist, aryl hydrocarbon receptor, transformation inhibitor, dietary phytochemical
NCBI PubMed ID: 10913616Apples 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)00124-7Following the extraction of Castanea sativa with an aqueous solution of sulfuric acid (pH 3.0), the ethyl acetate soluble fraction was tested for its antibacterial and allelopathic activity. The extract was shown to have pronounced antibacterial effects against seven of the eight strains of Gram-positive and Gram-negative bacteria used (MIC in the range of 64-256 μg/ml and MBC in the range of 256-512 μg/ml). The active fraction was analyzed by TLC and HPLC showing the presence of rutin, hesperidin, quercetin, apigenin, morin, naringin, galangin and kaempferol. Standards of the identified flavonoids were tested against the same bacterial strains. The highest activity was shown by quercetin, rutin and apigenin. The allelopathic effect was tested against Raphanus sativus seed germination. The extract, quercetin, rutin and apigenin caused a decrease in the percentage of seed germination and root and epicotyl growth.
antibacterial activity, flavonoids, Castanea sativa, allelopathic activity
NCBI PubMed ID: 10930721As 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/BF02491573The antimicrobial activity of a methanol extract and isolated constituents of Mitracarpus scaber, a species used in folk medicine by West African native people, was evaluated against Staphylococcus aureus and Candida albicans strains. The mitracarpus methanol extract possesses both antibacterial and antimycotic activities (minimum inhibitory concentration-MIC 31.25 and 62.50 μg/ml, respectively). This extract was subsequently fractioned and monitored by bioassays leading to the isolation of seven compounds screened for antibacterial and antimycotic activities. Among these compounds, gallic acid and 3,4,5-trimethoxybenzoic acid inhibited the growth of Staph. aureus (MIC 3.90 and 0.97 μg/ml). 4-Methoxyacetophenone and 3,4,5-trimethoxyacetophenone effectively inhibited C. albicans (MIC 1.95 μg/ml). The other compounds (kaempferol-3-O-rutinoside, rutin and psoralen) which were also isolated showed low antibacterial and antimycotic activities (125-500 μg/ml).
Staphylococcus aureus, Candida albicans, antimicrobial activity, Mitracarpus scaber, West African medicine
NCBI PubMed ID: 10736009The effects of extracts, partially purified fractions and four flavonol glycosides 1-4 from Aristeguietia discolor were investigated on the naloxone-precipitated withdrawal contraction of the acute morphine dependent guinea-pig ileum in vitro. After a 4 min in vitro exposure to morphine a strong contraction of guinea-pig isolated ileum was observed after the addition of naloxone. Both MeOH extract (50, 100 and 200 mg/mL), the partially purified fractions I, L, M and N (50, 100 and 200 mg/mL) and flavonol glycosides 1-4 (100, 50, 10 μM), injected 10 min before morphine, were capable of blocking the naloxone-induced contraction after exposure to morphine in a concentration-dependent fashion. The results of the present paper suggest that flavonol glycosides from Aristeguietia discolor may play an important role in the control of morphine withdrawal.
guinea-pig ileum, Aristeguietia discolor, morphine, naloxone
NCBI PubMed ID: 11054845The present study examines the effects of the extracts [petroleum ether, CHCl3, CHCl3/MeOH (9:1) and MeOH], partially purified fractions and pure compounds from Croton menthodorus on the electrically induced contractions of the isolated guinea-pig ileum (ECI). The results of the experiments indicate that CHCl(3)/MeOH (9:1) and MeOH extracts, tested at concentrations of 100, 50 and 25 μg/mL, dose-dependently reduced the guinea-pig ileum contractions, whereas petroleum ether and CHCl3 extracts did not affect it. Furthermore, the partially purified fractions III-VI from the CHCl3/MeOH extract, each tested at concentrations of 100, 50 and 25 μg/mL also inhibited ECI. Finally, pure compound 1 (6, 3, 1 μM) isolated and purified from the most active fraction III significantly reduced, in a dose-dependent manner, the electrical contractions of the ileum. Compound 1 was identified by NMR and EI-MS data as the morphinandien-7-one, O-methylflavinantine.
flavonol glycosides, guinea-pig ileum, Croton menthodorus, electrically induced contractions, O-methylflavinantine
NCBI PubMed ID: 10815006A method based on capillary electrophoresis with electrochemical detection (CE-ED) was developed for the determination of daidzein, rutin and quercetin. The effects of some important factors such as the acidity and concentration of running buffer, separation voltage, injection time, and detection potential were investigated to acquire the optimum conditions. The working electrode was a 300 μm diameter carbon disc electrode positioned opposite the outlet of capillary. The three analytes could be well separated within 10 min in a 40 cm length capillary at a separation voltage of 12 kV in a 100 mmol/l borate buffer (BB, pH 9.0). The response was linear over three orders of magnitude with detection limits (S/N=3) ranged from 0.190 to 0.434 μmol/l for all compounds. This proposed method demonstrated good long-term stability and reproducibility with relative standard deviations (R.S.D.) of less than 5% for both migration time and peak current (n=7). It has been successfully applied for the determination of rutin and quercetin in Chinese traditional drug, Flos Sophorae buds and in the leaves of Ligustrum lucidum Ait. and Cinnamomum camphora (L.) Presl.
capillary electrophoresis, quercetin, rutin, daidzein, electrochemical detection
Publication DOI: 10.1016/S0003-2670(00)01099-0Reactive oxygen species (ROS) are known to modulate activities of a host of kinases, phosphatases and transcription factors. Rutin and chlorogenic acid (CGA) are the major polyphenolic antioxidants present in the small molecular fraction of smokeless tobacco leaf extracts, as ascertained by reverse-phase high-pressure liquid chromatography (HPLC) and mass spectrometry. Levels of intracellular ROS in resting versus antigen-immunoglobulin E (IgE)-challenged murine mast cells were measured at 510 nm by fluorescence-activated cell sorting (FACS) using carboxy-dichlorofluorescein (DCFH-DA). Enhanced ROS production was observed in IgE-sensitized mast cells following antigenic challenge. Rutin and CGA reduced ROS levels in antigen-IgE-activated mast cells. Concomitantly, they also profoundly inhibited histamine release by these activated mast cells. In contrast, rutin and CGA augmented the inducible cytokine messages, i.e. interleukin (IL)-10, IL-13, interferon-gamma (IFN-γ), IL-6 and tumour necrosis factor-alpha (TNF-α) in IgE-sensitized mast cells following antigen challenge. This study indicates that tobacco polyphenolic antioxidants that quench intracellular ROS, differentially affect two effector functions of antigen-IgE-activated mast cells. This model system may be employed to determine the molecular target of polyphenols. The potential role of these polyphenolic antioxidants on IgE-mediated allergy in vivo depends on a balance of their differential effects on mast cell activation.
Antioxidants, reactive oxygen species (ROS), rutin, chlorogenic acid
NCBI PubMed ID: 10929074Thirteen compounds have been isolated from the methanol extract of Saxifraga cuneifolia L. (Saxifragaceae) whole plant. These were identified as five new compounds, (E)-5-O-β-D-glucopyranosyl-stilbene-3,3', 4,5'-tetraol, (E)-4-O-β-D-glucopyranosyl-5-methoxy-stilbene-3,3',5'-triol, 4-[4'-O-(6''-O-galloyl-β-D-glucopyranosyl)-3'-hydroxyphenyl]butan-2-one, 3-O-(6''-O-galloyl-β-D-glucopyranosyl)-epigallocatechin and 3-O-β-D-glucopyranosyl-epigallocatechin, together with the known compounds 4-[4'-O-β-D-glucopyranosyl-3'-hydroxyphenyl]-butan-2-one, (R)-rhododendrin, 1-O-galloyl-β-D-glucose, catechin, 3-O-galloyl-epigallocatechin, gallocatechin, clitorin and rutin, by chemical and spectroscopic methods. Their free radical scavenging properties are also described.
flavonoid glycosides, free radical scavengers, Saxifragaceae, catechin derivatives, phenylbutan-2-one glycosides, (R)-rhododendrin, Saxifraga cuneifolia, stilbene glycosides
NCBI PubMed ID: 21214466Our food contains, in addition to the many well-known major (protein, fat, carbohydrate, and fiber) and minor (vitamins, minerals, and nonessential compounds) nutrients, thousands of naturally present toxic plant compounds. Some are known or strongly suspected to cause cancer in laboratory animals and, thus, may be potentially carcinogenic in people. Many of these compounds are commonly termed "nature's pesticides" because they are often toxic to predators, such as insects and animals, thereby conferring a competitive advantage to the plant that produces them. Other natural toxins in plants have no known role. Although these chemicals are in every meal we eat, they have received little attention compared to that given to minute residues of synthetic chemicals such as PCBs and pesticides. Our food contains significantly greater amounts of natural plant toxins and carcinogens than the synthetic kind, and our bodies aren't able to distinguish between the two. Still, while popular notion remains that "natural is good," it is clear that natural toxins pose a far greater health risk than that posed by synthetic chemicals in our foods.
Publication DOI: 10.1201/9781420038316.ch6Flavonoids (polyphenols) are an important class of dietary antioxidants largely distributed in plants. In spite of their very fast reaction with lipid peroxyl radicals, flavonoids are relatively modest inhibitors of lipid peroxidation in solution. In addition, the absence of lag phase and the strong dependence of the antioxidant efficiency (the ratio of the rate constant of chain break to the rate constant of chain propagation) on the antioxidant concentration both point to a nonclassic behaviour. The inhibition of linoleic acid peroxidation by quercetin (3,3′,4′,5,7-pentahydroxyflavone) and its 3-O-glycoside rutin (two ubiquitous dietary flavonoids and potent antioxidants) has been investigated by UV–visible spectroscopy in pH 7.4 micellar solutions of SDS at 37 °C. The chain-breaking antioxidant α-tocopherol and two synthetic amphiphilic quercetin ethers are also considered for comparison purposes. From the general mathematical treatment developed in this work, flavonoids appear as strong chain-breaking antioxidants whose overall antiperoxidizing activity is, however, strongly restricted by the chain-initiating activity of the flavonoid radicals formed during inhibition (prooxidant effect).
Antioxidant activity, quercetin, lipid peroxidation, rutin
Publication DOI: 10.1039/A910183GHigh-speed countercurrent chromatography (HSCCC) was applied to the separation of polyphenols from tea leaves (Camellia sinensis L.). The capability of HSCCC to isolate pure tea polyphenols from complex mixtures on a preparative scale was demonstrated for catechins, flavonol glycosides, proanthocyanidins, and strictinin from green and black tea. The purity and identity of isolated compounds was confirmed by (1)H NMR and HPLC-ESI-MS/MS. Gram quantities of polyphenols from tea can be isolated with the procedure described.
high-speed countercurrent chromatography, flavonol glycosides, Camellia sinensis, polyphenols, catechins, green tea, black tea, HPLC-ESI-MS, proanthocyanidins, strictinin
NCBI PubMed ID: 10956128A flavonol glycoside, 3-[[6-O-(6-deoxy-α-L-mannopyranosyl)-β-D-glucopyranosyl]oxi]-5,7-dihydroxy-8-[(4-hydroxy-3,5-dimethoxyphenyl)methyl]-2-(3,4-dihydroxypheny)-4H-1-benzopyran-4-one, trivially named goodyerin, was isolated from the whole plant of Goodyera schlechtendaliana, along with three known flavonoids, rutin, kaempferol-3-O-rutinoside and isorhamnetin-3-O-rutinoside. The structures were established by spectroscopic analysis.
flavonoids, Orchidaceae, Goodyera schlechtendaliana, goodyerin
NCBI PubMed ID: 10820819Eight 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: 10746883Quercetin is a flavonoid with a wide range of biological activities. It mainly occurs in plants as glycosides, such as rutin (quercetin rutinoside) in tea. Quercetin and rutin are used in many countries as vasoprotectants and are ingredients of numerous multivitamin preparations and herbal remedies. The primary objective was to characterise and compare the absorption and the pharmacokinetics of quercetin from quercetin aglycone and rutin. A secondary objective was to investigate which forms of quercetin are present in plasma. In this double blind, diet-controlled, two-period cross-over study, 16 healthy volunteers received three different doses of quercetin and rutin orally. The doses corresponded to 8 mg, 20 mg and 50 mg quercetin aglycone. Blood samples were obtained between 0 h and 32 h post-dose. The overall kinetic behaviour of quercetin differed remarkably after ingestion of quercetin aglycone or rutin. The mean area under the plasma concentration-time curve from 0 h to 32 h [AUC(0-32)] and maximum plasma concentration (Cmax) values of the two treatments were similar. However, time to reach Cmax (tmax) was significantly shorter after the quercetin aglycone treatment than after the rutin treatment (1.9, 2.7 and 4.8 versus 6.5, 7.4 and 7.5 h, for doses 1, 2 and 3, respectively). Also, the absorption of quercetin from quercetin aglycone was predictable and inter-individual variation was small. In contrast, after ingestion of rutin, inter-individual variations in AUC(0-32) and Cmax values were considerable and seemed to be associated with gender and use of oral contraceptives. Quercetin and rutin were found in plasma as glucuronides and/or sulfates of quercetin and as unconjugated quercetin aglycone, but no rutin was detected. In clinical trials, studying the effects of quercetin from rutin, bioavailability must be taken into consideration and plasma quercetin concentrations monitored. Whether our results apply to other glycosidic drugs as well, especially other rutosides, should be investigated.
quercetin, rutin, flavonoids
NCBI PubMed ID: 11151743High-performance liquid chromatography with diode-array detection has been used for the separation and quantitation of phenolics from fresh and processed green beans. Whole beans, pods and seeds of green beans were studied separately. Chromatographic profiles from pods were more complex than those found in seeds. Flavonol glycosides were confined to quercetin and kaempferol classes and they were typical of external parts of the fruit. Flavan-3-ols monomers ((+) catechin and (−) epicatechin) as well as procyanidins structures were identified in pods and seeds. Chromatographic profiles from processed beans revealed a polyphenolic composition similar to those found in pod fresh green beans. The chromatographic method was carefully validated in regard to precision and accuracy. High reproducibility of peak area (RSD<3%) and calibration slopes (RSD<4%) was obtained. Recoveries between 94–104% revealed good accuracy for the overall method. Application to quantitative determination in a representative number of samples allowed good knowledge of the phenolic composition of green beans (Phaseolus vulgaris v.vulgaris).
phenolics, column liquid chromatography, green beans, identification and quantitation
Publication DOI: 10.1007/BF02490789It is not uncommon to treat plant-derived foods and feeds with alkali. Such exposure to high pH is being used to recover proteins from cereals and legumes, to induce the formation of fiber-forming meat analogue vegetable protein, for preparing peeled fruits and vegetables, and for destroying microorganisms. In addition to their profound effects on functional and nutritional properties in such foods, such treatments may also cause other side reactions, including the destruction of natural polyphenolic compounds. Because plants contain a large number of structurally different antioxidant, anticarcinogenic, and antimicrobial polyphenolic compounds, it is of interest to know whether such compounds are stable to heat and to high pH. In this model study, the stability of the following natural polyphenols to pH in the range 3-11 was studied with the aid of ultraviolet spectroscopy: caffeic acid, (-)-catechin, chlorogenic acid, ferulic acid, gallic acid, (-)-epigallocatechin, rutin, and the nonphenolic compound trans-cinnamic acid. This study demonstrates that caffeic, chlorogenic, and gallic acids are not stable to high pH and that the pH- and time-dependent spectral transformations are not reversible. By contrast, chlorogenic acid is stable to acid pH, to heat, and to storage when added to apple juice. (-)-Catechin, (-)-epigallocatechin, ferulic acid, rutin, and trans-cinnamic acid resisted major pH-induced degradation. The results are rationalized in terms of relative resonance stabilization of phenoxide ions and quinone oxidation intermediates. The possible significance of these findings to food chemistry and microbiology is discussed.
plant phenols, cinnamic acid, gallic acid, rutin, ferulic acid, caffeic acid, chlorogenic acid, catechin, epigallocatechin, pH stability, ultraviolet spectra
NCBI PubMed ID: 10888506Methods for determining primary antioxidant activity were evaluated. A beta-carotene bleaching method and a free radical method using 2, 2-diphenyl-1-picrylhydrazyl (DPPH(*)) were modified to rapidly test samples for potential antioxidant activity. Malonaldehyde production in a linoleic acid emulsion system assayed by an HPLC method was also used to determine antioxidant and prooxidant activities initiated by a metal catalyst (Cu(2+)). All methods were used to assess activity of selected phenolic compounds including several anthocyanidins/anthocyanins and selected berry extracts. Most phenolic compounds had prooxidant activity at low concentrations, unlike synthetic antioxidants (BHA and BHT). Compounds with similar structures exhibited comparable trends in antioxidant activity. Antioxidant activity usually increased with an increase in the number of hydroxyl groups and a decrease in glycosylation. The antioxidant activity of many phenolic compounds and extracts was comparable to those of synthetic antioxidants using the beta-carotene bleaching and HPLC methods.
Antioxidant activity, phenolics, flavonoids, anthocyanins, prooxidant activity, berry extracts
NCBI PubMed ID: 10956156Total 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-GAtropine, 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)80025-3The 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: 10901280Antioxidant therapy has been shown to be beneficial in neurological disorders including Alzheimer's disease and cerebral ischemia. Glutamate-induced cytotoxicity in HT-4 neuronal cells has been previously demonstrated to be due to oxidative stress caused by depletion of cellular glutathione (GSH). The present study demonstrates that a wide variety of antioxidants inhibit glutamate-induced cytotoxicity in HT-4 neuronal cells. Low concentrations of alpha-tocopherol and its analogs were highly effective in protecting neuronal cells against cytotoxicity. Purified flavonoids and herbal extracts of Gingko biloba (EGb 761) and French maritime pine bark (Pycnogenol) were also effective. We have previously shown that pro-glutathione agents can spare GSH and protect cells from glutamate insult in a C6 glial cell model. The protective effects of nonthiol-based antioxidants tested in the HT-4 line were not mediated via GSH level modulation. In contrast, protective effects of thiol-based pro-glutathione agents alpha-lipoic acid (LA) and N-acetyl cysteine (NAC) corresponded with a sparing effect on GSH levels in glutamate-treated HT-4 cells. Glutamate-induced cytotoxicity in HT-4 cells is a useful model system for testing compounds or mixtures for antioxidant activity.
cytotoxicity, quercetin, antioxidation activity, rutin, HT-4 neuronal cells
NCBI PubMed ID: 10653482Three new jujubogenin glycosides, namely, 3''-O-acetylcolubrin (1); 3'',2' "-O-diacetylcolubrin (2), and 3''-O-acetyl-6''-O-trans-crotonylcolubrin (3), were isolated from the leaves of Colubrina asiatica, in addition to the known colubrin, rutin, and kaempferol 3-O-rutinoside. Compounds 1-3 were isolated and purified via a combination of chromatographic procedures, and determined structurally using spectroscopic methods.
isolation, jujubogenin glycosides, Colubrina asiatica
NCBI PubMed ID: 11087616The flavonol content of commercial capers (pickled flower buds of Capparis spinosa L., C. sicula Veill. in Duham. and C. orientalis Veill. in Duham.) produced in different Mediterranean countries (Spain, Italy, Greece, Turkey and Morocco) has been analysed. The content of quercetin 3-rutinoside, kaempferol 3-rutinoside; and kaempferol 3-rhamnosyl-rutinoside as well as the aglycones (quercetin and kaempferol) were evaluated by HPLC coupled with a diode-array detector. The free aglycones were not detected in the original flower buds, indicating that they were produced during the brining process. In addition, brining extracted most of the kaempferol 3-rhamnosyl rutinoside present in the original buds, this being a minor constituent in pickled capers. The average content of flavonoid glycosides in commercial capers was 5.18 mg/g fresh weight. When this value is converted to the corresponding aglycones (quercetin and kaempferol), capers provide an average of 3.86 mg/g fresh weight. A serving of capers (10 g) will provide 65 mg of flavonoid glycosides or the equivalent 40 mg of quercetin as aglycone.
flavonols, Capparis spinosa, Capparis sicula, capers
Publication DOI: 10.1007/s002170000220Three new phenol glycosides acylated with (+)-oleuropeic acid, cypellocarpins A (1), B (2), and C (3), along with seven known compounds, were isolated from the dried leaves of Eucalyptus cypellocarpa. Structures of the new compounds were determined on the basis of spectroscopic methods, including 2D NMR experiments and chemical degradation. These new compounds and a known related glucoside (7) showed potent in vitro antitumor-promoting activity in a short-term bioassay evaluating the inhibitory effect on Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoyl phorbol 13-acetate (TPA). These compounds also suppressed an in vivo two-stage carcinogenesis induced with nitric oxide and TPA on mouse skin.
antitumor activity, cypellocarpins, Eucalyptus cypellocarpa, carcinogenesis, Epstein-Barr virus
NCBI PubMed ID: 11000030The 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)00060-5Under the inhibition of Cu+2-induced LDL oxidation-guided fractionation, two new flavone glycosides with galloyl substitution were isolated from the dried fallen leaves of Terminalia catappa L. Their structures were established as apigenin 6-C-(2″-O-galloyl)-β-D-glucopyranoside (1) and apigenin 8-C-(2″-O-galloyl)-β-D-glucopyranoside (2), together with four known flavone glycosides, isovitexin, vitexin, isoorientin, and rutin, on the basis of spectroscopic method. Compounds 1 and 2 showed significant antioxidative effects. Their IC50 were 2.1 and 4.5 μM, respectively.
Antioxidant, Combretaceae, Terminalia catappa L., dried fallen leaves, flavone glucopyranosides
Publication DOI: 10.1002/jccs.200000030The low-energy collision-induced dissociation of protonated flavonoid O-diglycosides, i.e., flavonoid O-rutinosides and O-neohesperidosides, containing different aglycone types has been studied. The results indicate that the unusual [M+H-162]+ ion formed by internal glucose residue loss, which in a previous study was shown to be a rearrangement ion, is strongly dependent upon the aglycone type. For 7-O-diglycosides, the internal glucose loss is very pronounced for aglycones of the flavanone type, but is completely absent for aglycones of the flavone and flavonol types. Internal glucose residue loss was found to correspond to a minor fragmentation pathway for flavonol 3-O-diglycosides. A plausible mechanism is proposed based on proton mobilization from the aglycone to the disaccharidic part of the flavonoid O-diglycosides which is supported by theoretical calculations and model building.
NCBI PubMed ID: 10689666Epidemiological studies consistently indicate that consumption of fruits and vegetables lowers cancer risk in humans and suggest that certain dietary constituents may be effective in preventing colon cancer. Plant-derived phenolic compounds manifest many beneficial effects and can potentially inhibit several stages of carcinogenesis in vivo. In this study, we investigated the efficacy of several plant-derived phenolics, including caffeic acid phenethyl ester (CAPE), curcumin, quercetin and rutin, for the prevention of tumors in C57BL/6J-Min/+ (Min/+) mice. These animals bear a germline mutation in the Apc gene and spontaneously develop numerous intestinal adenomas by 15 weeks of age. At a dietary level of 0.15%, CAPE decreased tumor formation in Min/+ mice by 63%. Curcumin induced a similar tumor inhibition. Quercetin and rutin, however, both failed to alter tumor formation at dietary levels of 2%. Examination of intestinal tissue from the treated animals showed that tumor prevention by CAPE and curcumin was associated with increased enterocyte apoptosis and proliferation. CAPE and curcumin also decreased expression of the oncoprotein beta-catenin in the enterocytes of the Min/+ mouse, an observation previously associated with an antitumor effect. These data place the plant phenolics CAPE and curcumin among a growing list of anti-inflammatory agents that suppress Apc-associated intestinal carcinogenesis.
anticancer activity, phenolics, natural compounds, adenomatous polyposis
NCBI PubMed ID: 10783313An acetone/water extract of the fodder legume Onobrychis viciifolia afforded arbutin, kaempferol, quercetin, rutin, afzelin, the branched quercetin-3-(2(G)-rhamnosylrutinoside), the amino acid L-tryptophan, the inositol (+)-pinitol, and relatively high concentrations of sucrose (ca. 35% of extractable material). Acid-catalyzed cleavage of the condensed tannins with phloroglucinol afforded catechin, epicatechin and gallocatechin as the terminal and extender units, but epigallocatechin was only present in extender units. The condensed tannins in O. viciifolia presumably consist of hetero- and homopolymers containing both procyanidin and prodelphinidin units. Comparison of data from the present study and the literature suggests that sainfoin tannins have a highly variable composition with cis:trans ratios ranging from 47:53 to 90:10 and delphinidin:cyanidin ratios from 36:64 to 93:7. The composition of terminal and extender units in sainfoin tannins seems to be cultivar specific.
Onobrychis viciifolia; sainfoin; arbutin; sucrose; (+)-pinitol; tryptophan derivatives; flavonols; condensed tannins
NCBI PubMed ID: 10956131A 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: 11216481The 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: 11114003Members of the genus Wrightia, viz. W. tinctoria, W. tomentosa and W. coccinea, have been investigated for their chemical constituents with a view to locating their bioactive principles. Indigotin 3, indirubin 6, tryptanthrin 8, isatin 5, anthranillate 7 and rutin 9 have been isolated and identified as major constituents of W. tinctoria and W. tomentosa. Anthranillate 7 and rutin 9 are the major constituents of W. coccinea. The identities of these compounds have been established by comprehensive chromatographic (HPTLC, HPLC) and spectroscopic (UV-VIS, IR, EI-MS) techniques, using markers and by synthesis, where possible. While indigotin is found to be native in the living plants (in fresh leaves), indirubin was found to be an artifact formed only during drying process after harvesting of the leaves. This transformation is presumably caused by the intact hydrolytic enzyme system(s) and by autoxidation. Seasonal variation studies of the chemical constituents of leaves, using HPTLC and HPLC analyses, revealed similar variation patterns in the three species. The concentration of indigotin-indirubin combination steadily increases from August to November. In contrast, concentration of isatin and anthranillate increases in the months of December and January, at the expense of indigotin-indirubin. Isatin is produced by the autoxidation of indigotin. Tryptanthrin concentration also increases, periodically, in May (at the expense of isatin) and in January. Plausible pathways for the formation of these indole metabolites are appraised on the basis of circumstantial and synthetic evidence.
flavonoids, indican, indole constituents, Wrightia genus
Journal NLM ID: 7613422A variety of flavonoids, lignans, an alkaloid, a bisbenzyl, coumarins and terpenes isolated from Chinese herbs was tested for antioxidant activity as reflected in the ability to inhibit lipid peroxidation in rat brain and kidney homogenates and rat erythrocyte hemolysis. The pro-oxidant activities of the aforementioned compounds were assessed by their effects on bleomycin-induced DNA damage. The flavonoids baicalin and luteolin-7-glucuronide-6'-methyl ester, the lignan 4'-demethyldeoxypodophyllotoxin, the alkaloid tetrahydropalmatine, the bisbenzyl erianin and the coumarin xanthotoxol exhibited potent antioxidative activity in both lipid peroxidation and hemolysis assays. The flavonoid rutin and the terpene tanshinone I manifested potent antioxidative activity in the lipid peroxidation assay but no inhibitory activity in the hemolysis assay. The lignan deoxypodophyllotoxin, the flavonoid naringin and the coumarins columbianetin, bergapten and angelicin slightly inhibited lipid peroxidation in brain and kidney homogenates. It is worth stressing that the compounds with antioxidant effects in this assay, with the exception of tetrahydropalmatin and tanshinone I, have at least one free aromatic hydroxyl group in structure. Obviously, the aromatic hydroxyl group is very important for antioxidative effects of the compounds. None of the compounds tested exerted an obvious pro-oxidant effect.
plant, Antioxidant, hemolysis, peroxidation
NCBI PubMed ID: 10680579The constituents of the fruits of Forsythia suspensa VAHL (Oleaceae) on the market were investigated. Betulinic acid, oleanolic acid, phillygenin, (+)-pinoresinol, phillyrin, and rutin were isolated from the methanolic extract and respectively identified with authentic samples.
Publication DOI: 10.1248/YAKUSHI1947.97.10_1134Different 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/BF02492820Several polyphenols have been tested in grape berries from Spain. The flavonoid content is important because of the pharmacological properties of these compounds, whereas resveratrol has been proved to be an antifungal, antiinflammatory and an anticarcinogenic compound. A reversed-phase HPLC method has been developed and applied to determine resveratrol, quercetine, quercitrine and rutine content in several grape berries samples in a single analysis. Covering the grapes with a preservative paper yields a healthier product, but one which has a lower polyphenol content than unprotected grapes.
fruits; food analysis; polyphenols; flavonoids
NCBI PubMed ID: 10722101Plant phenolics, especially dietary flavonoids, are currently of growing interest owing to their supposed functional properties in promoting human health. Antimicrobial screening of 13 phenolic substances and 29 extracts prepared from Finnish plant materials against selected microbes was conducted in this study. The tests were carried out using diffusion methods with four to nine microbial species (Aspergillus niger, Bacillus subtilis, Candida albicans, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Saccharomyces cerevisiae, Staphylococcus aureus and Staphylococcus epidermidis). Flavone, quercetin and naringenin were effective in inhibiting the growth of the organisms. The most active plant extracts were purple loosestrife (Lythrum salicaria L.) against Candida albicans, meadowsweet (Filipendula ulmaria (L.) Maxim.), willow herb (Epilobium angustifolium L.), cloudberry (Rubus chamaemorus L.) and raspberry (Rubus idaeus L.) against bacteria, and white birch (Betula pubescens Ehrh.), pine (Pinus sylvestris L.) and potato (Solanum tuberosum. L.) against gram-positive Staphylococcus aureus.
antimicrobial activity; inhibition; flavonoids; phenolics; plants; berries
NCBI PubMed ID: 10857921Nine commercial brands of grapefruit juice were analyzed for their flavonoid content by HPLC to determine if significant brand-to-brand variance in grapefruit juice flavonoid content exists. Flavonoid glycosides narirutin, naringin, hesperidin, neohesperidin, didymin, and poncirin have been identified in all the grapefruit juices examined. The aglycone quercetin was detected in only two brands. All the juices were free from methoxylated flavonoid aglycones. There was a significant difference in the amounts of total flavonoids and individual flavonoids in the nine brands. The concentration of total flavonoids ranged between 19.44 and 84.28 mg/100 ml juice. Naringin was found to be the major flavonoid followed by narirutin and hesperidin. Their concentrations ranged from 14.56 to 63.8; 2.25 to 12.20; and 0.24 to 3.12 mg/100 ml juice, respectively.
grapefruit juice; flavonoids; HPLC
NCBI PubMed ID: 10727812The ability of 20 compounds, all but one tobacco constituents, to inhibit the formation of tobacco-specific N-nitrosamines (TSNA) was investigated in buffer and detergent solution and in tobacco midrib and lamina systems. In solution at pH 5.5, ascorbic acid and the phenolic acids caffeic and ferulic acid were the most potent inhibitors of the reaction between nornicotine and nitrite, with nearly complete inhibition at molar ratios test compound/nitrite > 1:1. Also, cysteine > dihydrocaffeic acid > protocatechuic acid approximately catechin acted as strong inhibitors with >90% inhibition at a ratio of 3:1. Lower inhibitions were observed with chlorogenic acid > p-coumaric acid > sclareol > serine. Rutin showed an inhibition of 34% at a ratio of 0.1:1. Sclareol, alanine, proline, and serine did not significantly affect the N-nitrosonornicotine (NNN) formation. alpha-Tocopherol and glutathione enhanced NNN formation at pH 5.5 but were inhibitors at pH 3. Cinnamic acid, vanillic acid, eugenol, and esculin enhanced NNN formation. Increased NNN formation was also observed for dihydrocaffeic acid, chlorogenic acid, protocatechuic acid, and catechin at a less-than-equimolar ratio of test compound to nitrite. The tobacco matrix experiments were performed with air-cured, ground tobacco midrib and lamina. Caffeic acid, ferulic acid, dihydrocaffeic acid and catechin were potent inhibitors of the formation of TSNA in the midrib as well as in the lamina. Also protocatechuic acid, glutathione, ascorbic acid, p-coumaric acid, chlorogenic acid and cysteine were inhibitors, while alpha-tocopherol and rutin inhibited the reaction in the midrib but not in the lamina. Cinnamic acid, vanillic acid, eugenol, alanine, proline and serine showed small effects only. The molar ratio of secondary alkaloid(s)/nitrite in the test systems were 0.1:1 (solution), approximately 0.25:1 (midrib), and approximately 1:1 (lamina) and is most likely the major contributor to the observed order of inhibition potency (solution > midrib > lamina) of the test compounds. The vicinal phenolic hydroxyl groups of polyphenols and the simultaneous presence of a phenol group and an olefinic bond in hydroxycinnamic acids were the most characteristic structural elements of the potent inhibitors.
Tobacco-specific N-nitrosamines; nitrosation; nornicotine; secondary alkaloids; nitrite scavengers; ascorbic acid; R-tocopherol; phenolic acids; flavonoids; coumarins, amino acids; tobacco matrix; midrib; lamina
NCBI PubMed ID: 10995367Seven new triterpenoid saponins, randiasaponins I (1), II (2), III (3), IV (4), V (5), VI (6) and VII (7) as well as two known ones, ilexoside XXVII (8) and ilexoside XXXVII (9), were isolated from the methanolic extract of the leaves of Randia formosa. The structures of the new saponins were established as 3-O-α-L-arabinopyranosyl-3β,19α,23-trihydroxyursa-12,20(30)-dien-28-oic acid 28-β-D-glucopyranosyl ester (1), 3-O-β-D-glucopyranosyl-(1 → 3)-α-L-arabinopyranosyl rotundic acid (2), 3-O-β-D-glucopyranosyl-(1 → 3)-α-L-arabinopyranosyl pomolic acid 28-β-D-glucopyranosyl ester (3), 3-O-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl pomolic acid 28-β-D-glucopyranosyl ester (4), 3-O-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl siaresinolic acid 28-β-D-glucopyranosyl ester (5), 3-O-α-L-arabinopyranosyl ilexosapogenin A 28-β-D-glucopyranosyl ester (6), and 3-O-β-D-glucopyranosyl ilexosapogenin A 28-β-D-glucopyranosyl ester (7), based on spectral and chemical evidence. Besides the saponins, two common flavonoids kaempferol 3-O-rutinoside and rutin were also isolated.
pomolic acid, siaresinolic acid, triterpenoid saponins, 3β, Rubiaceae, rotundic acid, ilexosapogenin A, Randia formosa, 19α, 23-trihydroxy-ursa-12, 20(30)-dien-28-oic acid
NCBI PubMed ID: 10846751The methanol extract of the leaves of Cerbera manghas L. was treated and from the ethyl acetate fraction, succinic acid, nicotiflorin, and rutin, and from the aqueous layer L-(+)-bornesitol were isolated and identified respectively with authentic samples.
NCBI PubMed ID: 1035940Litchi (Litchi chinensis, Sapindaceae) is a nonclimacteric subtropical fruit that, once harvested, loses its red pericarp color because of browning reactions probably involving polyphenols. Low-pressure chromatography, high-pressure liquid chromatography, UV-visible spectral analysis, mass spectrometry, and nuclear magnetic resonance studies have allowed the determination and quantification of the polyphenolic composition of litchi pericarp. Litchi skins contain significant amounts of polyphenolic compounds. The principal characteristic of the litchi skin polyphenolic compounds is their ortho-diphenolic structure, which gives them high oxidability. Four major pigments were formally identified as cyanidin 3-rutinoside, cyanidin glucoside, quercetin 3-rutinoside (rutin), and quercetin glucoside. The tannin content was characterized after the depolymerization thiolysis reaction. Tannins (polymeric proanthocyanidins) are mainly constituted with epicatechin units linked by A- and B-type bonds. The different phenolic compounds of litchi cv. Kwai Mi were quantified by HPLC. Condensed tannins were the most abundant (4 mg/g of fresh skin), followed by epicatechin and procyanidin A2 (1.7 and 0.7 mg/g of fresh pericarp, respectively). The amount of anthocyanins was found to be comparable to that of flavonols, with a value of approximately 0.4 mg/g of fresh pericarp.
Litchi; polyphenols; anthocyanins; flavonols; proanthocyanidins; condensed tannins; characterization; quantification
NCBI PubMed ID: 11312772In 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: 11449469Rutin is one of the most widespread flavonoid compounds in plants; it occurrs especially frequently in the leaves of higher plants. In commercial practice, this substance is usually isolated from Sophora japonica (pagoda tree), the flowers and flower buds of which contain up to 20% rutin. Rutin is capable of controlling the permeability of capillaries, for which reason this compound is included in P-vitamin compositions. The alcohol solutions of rutin obey the Lambert-Bouguer-Beer law in a broad range of optical densities and retain stable optical absorption properties for about a one-month storage period. Due to this circumstance and the availability of rutin, this compound is employed more frequently than other γ-pyrones as a reference substance in the analysis of drugs and for the standardization of raw plant materials and phytopreparations with respect to the total content of phenols, in particular, the sum of flavonoids. In Russia, the State Standard Sample of rutin is obtained from a readily available domestic natural material - the herbs of common buckwheat. The rutin standard produced at the VILAR according to the State Technological Conditions TU 64-4-127-96 satisfies all present-day requirements of the State Pharmacopoeia and the WHO recommendations, representing a high-purity preparation characterized by modern analytical techniques, including UV spectrophotometry, 1H NMR spectroscopy, and HPLC. However, work with rutin standards is complicated by the high hygroscopicity of this substance, the water content being extremely sensitive to the hydrothermal conditions in the ambient medium. As is known, an uncertainty in determining water content in the standard sample may cancel all advantages gained from the use of high-purity reference substances in HPLC, TLC, or spectroscopic analyses. Previously [1], we have reported on the hygroscopicity of rutin investigated by DSC in the course of drying and water absorption, in combination with some other aquametric and gravimetric techniques. The main conclusion drawn from the study was the requirement of permanently controlling water content in the standard sample used in the analytical work. However, the experimental conditions studied in that work were rather different from those encountered in pharmaceutical practice. Indeed, small (5-8 mg) samples sealed in aluminum cells and studied under nitrogen flow conditions minimized the contact of rutin with the environment. The purpose of this work was to study the behavior of rutin in contact with water vapor under real analytical conditions simulating those stipulated by the State Pharmacopoeia (XI Ed., RSP-XI) and special Pharmacopoeial Clauses. Our recommendations concerning application of the rutin standard would allow analysts to avoid errors caused by the uncontrolled water sorption by rutin.
rutin, water sorption, ambient medium, equilibrium water content, common buckwheat
Publication DOI: 10.1007/BF02524555The 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: 9714997Chromosomal translocations involving the MLL gene occur in about 80% of infant leukemia. In the search for possible agents inducing infant leukemia, we identified bioflavonoids, natural substances in food as well as in dietary supplements, that cause site-specific DNA cleavage in the MLL breakpoint cluster region (BCR) in vivo. The MLL BCR DNA cleavage was shown in primary progenitor hematopoietic cells from healthy newborns and adults as well as in cell lines; it colocalized with the MLL BCR cleavage site induced by chemotherapeutic agents, such as etoposide (VP16) and doxorubicin (Dox). Both in vivo and additional in vitro experiments demonstrated topoisomerase II (topo II) as the target of bioflavonoids similar to VP16 and Dox. Based on 20 bioflavonoids tested, we identified a common structure essential for topo II-induced DNA cleavage. Reversibility experiments demonstrated a religation of the bioflavonoid as well as the VP16-induced MLL cleavage site. Our observations support a two-stage model of cellular processing of topo II inhibitors: The first and reversible stage of topo II-induced DNA cleavage results in DNA repair, but also rarely in chromosome translocations; whereas the second, nonreversible stage leads to cell death because of an accumulation of DNA damage. These results suggest that maternal ingestion of bioflavonoids may induce MLL breaks and potentially translocations in utero leading to infant and early childhood leukemia.
doxorubicin, acute myelogenous leukemia, acute lymphoblastic leukemia, etoposide, topoisomerase II
NCBI PubMed ID: 10758153Experiments were conducted on Phillyrea latifolia plants grown under a dense overstorey of Pinus pinea (shade plants) or on seashore dunes (sun plants) in a coastal area of Tuscany (42° 46′ N, 10° 53′ E). Total integrated photon flux densities averaged 1.67 and 61.4 m mol/m^2/d for shade and sun sites, respectively. A leaf morphological–structural analysis, a qualitative and quantitative analysis of phenylpropanoids of leaf tissue and leaf surface, and a histochemical localization of flavonoids were conducted. The area of sun leaves reached 57% of that of shade leaves, whereas leaf angle (β), sclerophylly index (ratio of leaf d. wt:leaf area), and trichome frequency (trichome number mm−2 ) were markedly greater in leaves exposed to full solar radiation than in leaves acclimated to shade. The total thickness of sun leaves was 78% higher than that of shade leaves, mostly owing to a greater development of both palisade parenchyma and spongy mesophyll. The concentration, but not the composition, of leaf tissue phenylpropanoids varied significantly between sun and shade leaves, with a marked increase in flavonoid glycosides in sun leaves. Flavonoids occurred almost exclusively in the upper epidermal cells of shade leaves. By contrast, flavonoids largely accumulated in the upper and lower epidermis, as well as in the mesophyll tissue of leaves that were acclimated to full sunlight. Flavonoid glycosides were found exclusively in the secretory products of glandular trichomes of P. latifolia leaves exposed to high levels of light; luteolin 7-O- glucoside and quercetin 3-O-rutinoside were the major constituents. By contrast, verbascoside and an unidentified caffeic acid derivative constituted 72% of total phenylpropanoids secreted by glandular trichomes of shade leaves, whereas they were not detected in glandular trichomes of sun leaves. These findings suggest that the light-induced synthesis of flavonoids in glandular trichomes of P. latifolia probably occurs in situ and concomitantly inactivates other branch pathways of the general phenylpropanoid metabolism. This is the first report of the key role of glandular trichomes and of flavonoid glycosides in the integrated mechanisms of acclimation of P. latifolia to excess light.
flavonol glycosides, Oleaceae, phenylpropanoids, fluorescence microscopy, glandular trichomes
NCBI PubMed ID: 33863030Glutathione S-transferases (GSTs) isolated from larval midguts of the fall armyworm, Spodoptera frugiperda, were used to study their sensitivity to inhibition by 44 chemicals, most of which were plant allelochemi cals. Many flavonoids, other phenols, and α,β-unsaturated carbonyl compounds were potent inhibitors of the enzymes. For the flavonoids, apigenin was the best inhibitor among those studied, showing an I50 value of 0.82 μM. In general, flavonols exhibited higher inhibitory potencies than flavones; flavonoid glycosides were less inhibitory than their corresponding aglycones. In the case of phenols, tannic acid was the best inhibitor among those tested, showing an I50 value of 0.2 μM. The organotin compound chlorotriphenyltin was an potent as tannic acid in inhibiting the transferases. For the αβ-unsaturated carbonyl compounds, ethacrynic acid was the most potent inhibitor among those examined, showing an I50 value of 0.15 μM. However, the isothiocyanates were found to be marginal inhibitors of GSTs. GSTs isolated from larval fat bodies showed differential sensitivity to inhibition by some selected inhibitors compared with midgut GSTs. Kinetic studies of midgut GSTs revealed that ellagic acid exhibited a noncompetitive inhibition toward 1-chloro-2, 4-dinitrobenzene (CDNB) but a competitive inhibition toward glutathione (GSH). In contrast, inhibition by tannic acid and ethacrynic acid were noncompetitive toward both CDNB and GSH. Diethyl maleate did not affect GSH levels in midguts when larvae were topically treated with this compound for up to 24 h.
inhibition, flavonoids, glutathione S-transferase, Spodoptera frugiperda
Publication DOI: 10.1006/pest.2000.2514| New query | Export IDs | Home | Help |
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