GLYCYRRHETINIC ACID 24-HYDROXYLASE ACTIVITY IN MICROSOMES OF CULTUREDLICORICE CELLS

18beta-Glycyrrhetinic acid 24-hydroxylase activity was detected in the microsomal fraction prepared from Glycyrrhiza glabra cell suspension cultures. The enzymatic activity required both NADPH and O2. The parti cipation of cytochrome P-450 in the reaction was demonstrated by inhib itor experiments including the light reversibility of CO inhibition. T he 24-hydroxylation of 18beta-glycyrrhetinic acid was shown to be prer equisite to forming its 3-O-glycoside by glucuronylation which is cata lysed by a glucuronyltransferase localized also in the microsomal frac tion of cultured licorice cells.