Since its first description at the end of the nineteenth century , microbial steroid synthesis has been performed using a large variety of native microorgan isms such as eubacteria, actinomycetes, fungi imperfecti, and more. In 1937, the development of technically useful microbial processes in steroid production began at Schering with the synthesis of testosterone. After the pharmacological effects of cortisol and progesterone became known, research in this field developed rapidly in the 1950s and led to the identification of a panel of different microorganisms that catalyze steroid hydroxylations, hydrogenations, dehydroge-nations, and the splitting of carbon-carbon bonds (reviewed in detail by ). However, only a limited number of microbial transformations reported in the scientific literature have actually been applied technically. These comprise side-chain degradation reactions, A1,2-, A1,4-, 17P-dehydrogenation, and several hydroxylation reactions. Among the latter ones 11a-hydroxylation, 11P-hydroxyl-ation, and 16a-hydroxylation, are of the highest commercial significance and are therefore discussed in detail below.
Other steroid hydroxylation sites, including those at the positions 7a, 9a, 14a, and 15a, seem also to have potential for industrial exploitation. In addition, the 6P-hydroxylation of compound ML-236BNa to form the blockbuster drug pravastatin by Streptomyces carbophilus as well as the 1a- and 25-hydroxylations of the seco-steroid vitamin D3 by Amycolata species are prominent examples of P450-dependent biotransformations with native microorganisms on an industrial scale (see ). However, as the substrates of these latter reactions are not steroids, they fall out of the range of this survey.
Was this article helpful?