Inhibition of porcine liver carboxylesterase by a new flavone glucoside isolated from Deverra scoparia

Abstract

An endemic North African Saharan plant from of the Apiaceae family,Deverra scoparia, used locally for medicinal preparations,showed a strong inhibitory effect on porcine liver carboxylesterase. The active compound from the aerial part of the plant was purifiedby semi-preparative HPLC and photodiode array detection, and structurally determined by1H,13C NMR and mass spectroscopymethods. This compound was identified as flavone-3,4′,7-trihydroxy-3′-methoxy-7-glucoside and it was found to be a powerfulcompetitive inhibitor of porcine liver carboxylesterase with a inhibition constant value of 16 M. Based on the structural featuresof the inhibitor and the enzyme active site region, it seems that the flavonoside binds to the surface of the enzyme. The lowKivaluesuggests some physiological significance of such inhibitory activity, especially concerning the bio-transformation of xenobiotics.