Regioselective glucuronidation of flavonols by six human UGT1A isoforms.

ABSTRACT:

Purpose

Glucuronidation is a major barrier to flavonoid bioavailability; understanding its regiospecificity and reaction kinetics would greatly enhance our ability to model and predict flavonoid disposition. We aimed to determine the regioselective glucuronidation of four model flavonols using six expressed human UGT1A isoforms (UGT1A1, 1A3, 1A7, 1A8, 1A9, 1A10).

Methods

In vitro reaction kinetic profiles of six UGT1A-mediated metabolism of four flavonols (all with 7-OH group) were characterized; kinetic parameters (K(m), V(max) and CL(int) = V(max)/K(m)) were determined.

Results

UGT1A1 and 1A3 regioselectively metabolized the 7-OH group, whereas UGT1A7, 1A8, 1A9 and 1A10 preferred to glucuronidate the 3-OH group. UGT1A1 and 1A9 were the most efficient conjugating enz

SUBMITTER: Wu B 

PROVIDER: S-EPMC3426363 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature