Microbial introduction of a 16 alpha-hydroxyl function into the steroid nucleus.

The introduction of a 16 alpha-hydroxyl function into the steroid nucleus was studied in resting cells of Streptomyces roseochromogenes NRRL B-1233. The oxidation product of dehydroepiandrosterone (DHEA) was identified as 16 alpha-hydroxy DHEA by using thin-layer and gas-liquid chromatography. A linear relation between cell concentration and 16 alpha-OH-DHEA formation was observed. 16 alpha-Hydroxylase showed good activity at pH 8.0 for 16 alpha-OH-DHEA formation. The enzyme showed good activity at 3.1 x 10(-4) M DHEA. The oxidation products of pregnenolone, 4-androstene-3,17-dione, estrone, and 5-androstene-3 beta,17 beta-diol as well as of other substrates were identified as the 16 alpha-hydroxy steroid, respectively. The rates of microbial 16 alpha-hydroxylation were as follows: 76.9% for DHEA, 50.4% for pregnenolone, 43.9% for 4-androstene-3,17-dione, 34.3% for estrone, and 19.6% for 5-androstene-3 beta,17 beta-diol. The organism tested catalyzes 16 alpha-hydroxylation of a wide variety of steroids.