REACTIONS OF 20-HYDROXYLATED STEROIDS WITH BOVINE ADRENAL TISSUE PREPARATIONS

The reactivities of 20-methylpregn-5-ene-3β, 20-diol (I) and 22-dideuterocholest-5-ene-3β, 20-diol (II) were studied and compared with cholest-5-ene-3β, 20-diol (III) in a system prepared from bovine adrenal mitochondria. II and III both underwent the expected cleavage reaction between carbons 20 and 22 to give pregnenolone and subsequent products. The rates were very similar to each other indicating that if hydroxylation occurs at C-22, it is not a rate determining step in this system. Compound I did not undergo side-chain cleavage, but was rapidly converted to the corresponding 4-ene-3-one (V). No further reaction was observed during a 32-minute reaction period. V appeared to inhibit 21-hydroxylation of progesterone, however, no effect was observed on 11β-hydroxylation of 11-desoxycorticosterone. I was tested for inhibition of side-chain cleavage of III and for inhibition of the conversion of pregnenolone to progesterone. No effect was observed under our experimental conditions. © 1968.