ABSTRACT
The 11 beta-hydroxylase of the filamentous fungus Cochliobolus lunatus m 118 was induced with the substrate 17 alpha, 21-dihydroxypregna-1,4-diene-3,20-dione 17-acetate (11 beta-deoxyprednisolone 17-acetate) itself, substrate analogues, different pregnane compounds, sterols, intermediates of microbial sterol side-chain degradation or bile acids, together with 24 different steroids in a standardized test system. The resulting 11 beta-hydroxylation rate, leading to prednisolone 17-acetate and prednisolone, respectively, was determined and compared with the hydroxylation rate of non-induced cultures. The transformation yield strongly depended on the inducer structure. The microbial sterol side-chain degradation intermediates (20S)-20-hydroxymethylpregn-4-en-3-one and the corresponding pregna-1,4-diene compound caused the highest induction effects (induction factors 5.1 and 4.9, respectively). The metabolism of (20S)-20-hydroxymethylpregna-1,4-dien-3-one during the cultivation was elucidated. The induction effect decreased with the rising oxidation of the inducer. The significant increase of the 11 beta-hydroxylation rate of 1-dehydro-pregnane substrates by specific induction allows alternative pathways to glucocorticoid partial syntheses.
Subject(s)
Ascomycota/enzymology , Prednisolone/analogs & derivatives , Steroid 11-beta-Hydroxylase/metabolism , Enzyme Induction , Hydroxylation , Prednisolone/biosynthesis , Prednisolone/metabolism , Pregnanes/pharmacology , Structure-Activity RelationshipABSTRACT
Reichstein's compound S was successfully converted to prednisolone in a single-step fermentation using a mixed culture of Curvularia lunata and Mycobacterium smegmatis. Introducing additional medium at the time of bacterial inoculation and increasing the M. smegmatis inoculum to 8% were necessary for maximal dehydrogenation of cortisol to prednisolone (86%). However, beef extract, corn-steep solids, and malt extract were inhibitory to the dehydrogenase activity and stimulatory to hydroxylase. Of the vitamins tested, nicotinic acid and riboflavin at 0.2 and 1.13 mg/L, respectively, resulted in maximum transformation of Reichstein's compound S (100%) and optimized prednisolone yields (92%) in the mixed culture. The trace elements present in the medium were sufficient for maximal transformation, and there was no need for an exogenous supply. Addition of ATP, sodium acetate, and NAD inhibited the dehydrogenation reaction.
Subject(s)
Cortodoxone/metabolism , Culture Media/chemistry , Fungi/metabolism , Mycobacterium/metabolism , Prednisolone/biosynthesis , Biotransformation/drug effects , Enzyme Activation , Fermentation/drug effects , Trace Elements/pharmacology , Vitamins/pharmacologyABSTRACT
A method is described for obtaining epiprednisolone and its 21-acetate by means of microbiological 1,2-dehydration by a culture of Mycobacterium globiforme 193. The substrate, epihydrocortisone or its 21-acetate, is added in the form of a microcrystalline suspension at a concentration of 25-100 g/liter medium.
Subject(s)
Hydrocortisone/analogs & derivatives , Hydrocortisone/metabolism , Mycobacterium/metabolism , Crystallography , Prednisolone/analogs & derivatives , Prednisolone/biosynthesisABSTRACT
The role of a variety of compounds including organic acids, vitamins, growth promoting substances, purines and pyrimidines in the bioconversion of cortisol with Bacillus cereus was investigated. The transformation of cortisol to prednisolone and pregn-4-en-11beta, 17alpha,20beta, 21-tetrol-3-one was affected by these compounds in different manners. The enzymatic delta1-dehydrogenation reaction was greatly induced with fumarate, menadione, and xanthine treatments. However, the enzymic reduction of the 20-carbonyl to the 20beta-ol was specifically stimulated with fumarate, nicotinic acid amide, and uracil treatments.
