Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
NCBI PubMed ID: 11151743Publication DOI: 10.1007/s002280000197Journal NLM ID: 1256165Publisher: Berlin, New York, Springer
Correspondence: iris.erlund

ktl.fi
Institutions: Department of Nutrition, National Public Health Institute (KTL), Helsinki, Finland, Clinical Research, Leiras Oy, Helsinki, Finland
Quercetin 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
Structure type: oligomer
C
27H
30O
16
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
Methods: enzymatic hydrolysis, biological assays, HPLC, CC, centrifugation
NCBI Taxonomy refs (TaxIDs): 4442Reference(s) to other database(s): CCSD:
50720, CBank-STR:3399
Show glycosyltransferases
There is only one chemically distinct structure: