Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
NCBI PubMed ID: 11053519Publication DOI: 10.1093/jn/130.11.2765Journal NLM ID: 0404243Publisher: Rockville, MD: American Society for Nutrition
Institutions: Diet, Health and Consumer Sciences Division, Institute of Food Research, Norwich Research Park, Colney, UK
Flavonoids 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
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
Methods: biological assays, radiolabeling, radioactivity measurement, HPLC, UV, extraction, column chromatography, centrifugation
Related record ID(s): 65566
NCBI Taxonomy refs (TaxIDs): 33090Reference(s) to other database(s): CCSD:
49965, CBank-STR:953
Show glycosyltransferases
There is only one chemically distinct structure:
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