Systematic studies of sulfation and glucuronidation of 12 flavonoids in the mouse liver S9 fraction reveal both unique and shared positional preferences.

Sulfation and glucuronidation are the principal metabolic pathways of flavonoids, and extensive phase II metabolism is the main reason for their poor bioavailabilities. The purpose of this study was to compare the similarities and differences in the positional preference of glucuronidation versus sulfation in the mouse liver S9 fraction. The conjugating rates of seven monohydroxyflavones (HFs) (i.

Sulfation of selected mono-hydroxyflavones by sulfotransferases in vitro: a species and gender comparison.

Objectives: Sulfation via sulfotransferases is an important metabolic pathway contributing to the low bioavailability of flavonoids. This study aims to characterize the sulfation of mono-hydroxyflavones (MHFs) to obtain useful information on structure-metabolizing relationships in animal species and gender differences.

Methods: Three representative MHFs, namely, 7-, 6- and 4'-MHF, were studied by incubating each MHF at different concentrations with various liver S9 fractions (mouse, rat, dog and human).