Biosynthesis of lipoidal derivatives of pregnenolone and dehydroisoandrosterone by the adrenal.

The incubation of pregnenolone or dehydroisoandrosterone with bovine or rat adrenal homogenates leads to the formation of nonpolar metabolites of these steroids. The enzymatically prepared compounds have properties that are similar to the endogenous lipoidal derivatives of pregnenolone found in bovine adrenals (Hochberg, R. B., Bandy, L., Ponticorvo, L., and Lieberman, S. (1977) Proc. Natl. Acad. Sci. U. S. A. 74, 941-945) in that they are much less polar than the parent steroid and yield the parent steroid as a product of treatment with alkali. The lipoidal derivatives of both dehydroisoandrosterone and pregnenolone proved to be chromatographically heterogeneous. 17 alpha-Hydroxypregnenolone, 17 alpha-hydroxyprogesterone, progesterone, and testosterone were not converted into lipoidal derivatives when incubated with the bovine adrenal homogenate.