Pharmacokinetic comparison of quercetin, isoquercitrin, and quercetin-3-O-β-D-glucuronide in rats by HPLC-MS.

Quercetin, IQ, and QG can all be absorbed into plasma. A mutual transformation exists between Qr and QG, and IQ can be metabolized into Qr and QG in SD rats. These results would provide a meaningful basis for understanding the pharmacological actions of these three compounds.