title: Formation of 5 alpha steroids by biotransformation involving the 5 alpha-reductase activity of Penicillium decumbens.
abstract: The biotransformation of a series of delta 4-3-ketosteroids by the fungus Penicillium decumbens ATCC 10436 has been investigated. Conversion to the 5 alpha-dihydrosteroid was observed for several substrates of the androstene and pregnene series: the reaction is tolerant of non-polar substituents (Cl and CH3) at C-4 of the substrate, but does not occur in the presence of a 4-hydroxyl group, or with additional unsaturation at the delta 1 or delta 6 positions. A-nor-, B-nor-, 3-deoxy-, and 3,5-cycloandrostanes are not reduced, but 6-methylenetestosterone is converted to a 6-methylene-5 alpha-dihydro derivative. Several biotransformations are reported which involve oxidoreductase activity at C-3 and/or C-17, either concomitant or independent of delta 4 reduction: the substrate specificity of the oxidoreductase processes has been examined and defined by the use of 3 alpha-hydroxy, 3 beta-hydroxy, 3-keto, 17 beta-hydroxy and 17-keto substituted steroids. In this way, the existence in P. decumbens of 3 beta-hydroxy-3-keto and 17 beta-hydroxy-17-keto oxidoreductases has been demonstrated.
authors.affiliation: Department of Chemistry, Brock University, St. Catharines, Ontario, Canada.
authors.forename: H L
authors.initials: HL
authors.lastname: Holland
authors.forename: S
authors.initials: S
authors.lastname: Dore
authors.forename: W
authors.initials: W
authors.lastname: Xu
authors.forename: F M
authors.initials: FM
authors.lastname: Brown
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism*; D001711:Biotransformation; D007664:Ketosteroids / Q000378:metabolism*; D010407:Penicillium / Q000201:enzymology / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D007664:Ketosteroids; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase