Oral absorption and metabolism of quercetin and sugar-conjugated derivatives in specific transport systems.

The intestinal transport and metabolism of quercetin and various sugar-conjugates were quantified in in vitro and in vivo model systems. The nature of the sugar moiety at the C3 and C4' position had no significant effect on the rate of transport. At the 10 microM level, quercetin and glycosides with sugars at position 3 were determined to be glucose transport carrier inhibitors.