Microbiological transformations of steroids and their applications to the synthesis of hormones

Biotransformation of progesterone and testosterone enanthate by Circinella muscae

In this study, the biotransformation of progesterone (1) and testosterone enanthate (5) using the whole cells of Circinella muscae was investigated for the first time. Microbial transformation of 1 with C. muscae afforded three known metabolites including 9α-hydroxyprogesterone (2), 14α-hydroxyprogesterone (3) and 6β,14α dihydroxyprogesterone (4) after 6 days of incubation at 26 °C. The biotransformation of 5 with C. muscae yielded a new metabolite; 8β,14α-dihydroxytestosterone (8), in addition to two known metabolites; 6β-hydroxytestosterone (6), and 9α-hydroxytestosterone (7). The structure of the metabolites were established on the basis of spectroscopic data.

Transformation of steroids by spores of microorganisms. I. Hydroxylation of progesterone by conidia of Aspergillus ochraceus

Conidia of Aspergillus ochraceus convert progesterone into 11alpha-hydroxyprogesterone and 6beta, 11alpha-dihydroxyprogesterone. The conversion ability does not depend on the sporulation medium. Transformation depends on the strain and on the conidia concentration. Adaptation has never been observed. Age and storage of conidia, pH, aeration-agitation, nitrogen source, metal ions, chelating agents, and metabolic activators showed no great influence within wide limits. Mercuric chloride, p-chloromercuribenzoate, NaN(3), and KCN inhibit conversion. Glucose is necessary, but can be replaced completely by d(+)-xylose, and partially by some other carbon sources. The ratio mono-/di-hydroxyprogesterone is influenced by progesterone concentration and period of incubation; also, a mutant that accumulates only monohydroxyprogesterone has been produced. Conidia of A. ochraceus also hydroxylate a variety of steroids. Spores of certain streptomycetes, phycomycetes (mucors), ascomycetes, and deuteromycetes are active. Most reactions already observed with vegetative cells have been repeated with spores. In general, spores of a particular organism effect fewer reactions than its mycelium, and fewer products accumulate.

Microbiological synthesis of 16alpha, 18-dihydroxydeoxycorticosterone

16Alpha, 18-Dihydroxydeoxycorticosterone (16alpha, 18-dihydroxy-DOC) (1) and 1, 2-3H-16alpha, 18-dihydroxy-DOC (1,2-3H-16alpha, 18-dihydroxy-DOC) of high specific activity were obtained in good yield by microbiological hydroxylation of 18-OH-DOC and 1,2-3H-18-OH-DOC by Streptomyces roseochromogenus (ATCC 13400). The identity of the fermentation product to human adrenal produced 16alpha, 18-dihydroxy-DOC was established by chromatographic studies, derivative formation and gas-liquid chromatography. Yield of the product was about 30% of sutstrate and, allowing for losses in recovery, about 60% of the substrate 18-OH-DOC was converted to this product. A second product of fermentation isolated in lower yield appeared to be a dimer of 16alpha, 18-dihydroxy-DOC found in the acidic conditions of the fermentation. This method of synthesis of 16alpha, 18-dihydroxy-DOC is a practical way to make large quantities of the compound for further study of its possible role in human and experimental hypertension.

Continuous microbiological transformation of steroids

Continuous fermentation trials on the bioconversions of pregnadiene to pregnatriene by Septomyxa affinis and progesterone to 11alpha-hydroxyprogesterone by Rhizopus nigricans were conducted successfully in an eight-stage pilot plant reactor. The first stage was used as the mycelial growth stage while the steroid solutions were added continuously to stage 2, thus using the remaining stages as conversion vessels. Recoveries of 50 to 60% oxidized steroid (based on total steroid supplied) were obtained in both cases upon a contact time of 5 hr between mycelium and steroid. Longer contact times resulted in a gradual net loss of steroid. It was concluded that two-stage reactors (one growth stage and one conversion stage) were adequate for efficient continuous operation of such processes. The reaction volumes of both stages have to be kept in proper balance to insure optimal holdup times for both the cell growth and conversion steps.