Abstract
The metabolism of 27-nor-24, 25-dihydrolanosterol (1) which is an effective inhibitor of cholesterol biosynthesis from lanosterol was studied using the unlabeled and 24, 25-tritiated compounds. 1 was transformed into the cholesterol analog, 27-norcholesterol, to the extent of 6.5% by incubation with rat liver homogenate under conditions such that lanosterol in the control experiment was converted to cholesterol to the extent of 24.8%. The structures of two other metabolites (9 and 11) were determined. On the other hand, 23, 24, 25, 26, 27-pentanordihydrolanosterol (2), which is also an inhibitor, was not transformed into the corresponding cholesterol analog, suggesting the importance of the side chain structure of lanosterol in cholesterol biosynthesis.
