Inhibition of aldose reductase by dihydroflavonols in Engelhardtia chrysolepis and effects on other enzymes.

ABSTRACT

Astilbin and neoastilbin, dihydroflavonol rhamnosides from Engelhardtia chrysolepis, showed potent inhibition of lens aldose reductase. Kinetic analysis showed astilbin exhibited uncompetitive inhibition against both dl-glyceraldehyde and NADPH. These taxifolin glycosides were selective inhibitors of aldose reductase with no inhibition of NADH oxidase.