title: Microbial transformation of 17alpha-ethynyl- and 17alpha-ethylsteroids, and tyrosinase inhibitory activity of transformed products.
abstract: The microbial transformation of the 17alpha-ethynyl-17beta-hydroxyandrost-4-en-3-one (1) (ethisterone) and 17alpha-ethyl-17beta-hydroxyandrost-4-en-3-one (2) by the fungi Cephalosporium aphidicola and Cunninghamella elegans were investigated. Incubation of compound 1 with C. aphidicola afforded oxidized derivative, 17alpha-ethynyl-17beta-hydroxyandrosta-1,4-dien-3-one (3), while with C. elegans afforded a new hydroxy derivative, 17alpha-ethynyl-11alpha,17beta-dihydroxyandrost-4-en-3-one (4). On the other hand, the incubation of compound 2 with the fungus C. aphidicola afforded 17alpha-ethyl-17beta-hydroxyandrosta-1,4-dien-3-one (5). Two new hydroxylated derivatives, 17alpha-ethyl-11alpha,17beta-dihydroxyandrost-4-en-3-one (6) and 17alpha-ethyl-6alpha,17beta-dihydroxy-5alpha-androstan-3-one (7) were obtained from the incubation of compound 2 with C. elegans. Compounds 1-6 exhibited tyrosinase inhibitory activity, with compound 6 being the most potent member (IC(50)=1.72 microM).
authors.affiliation: H.E.J. Research Institute of Chemistry, International Center for Chemical Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
authors.forename: Sadia
authors.initials: S
authors.lastname: Sultan
authors.forename: Mahmud Tareq Hassan
authors.initials: MT
authors.lastname: Khan
authors.forename: Atta-Ur-
authors.initials: AU
authors.lastname: Rahman
mesh_terms: D000164:Acremonium / Q000201:enzymology*; D000730:Androstadienes / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D001711:Biotransformation / Q000187:drug effects; D003358:Cosmetics / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D005003:Ethisterone / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D005656:Fungal Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D017495:Hyperpigmentation / Q000188:drug therapy; D008543:Melanins / Q000096:biosynthesis; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009090:Mucorales / Q000201:enzymology*; D010084:Oxidation-Reduction / Q000187:drug effects; D013739:Testosterone / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology
chemical_list: C507308:17-ethyl-17-hydroxyandrost-4-en-3-one; D000730:Androstadienes; D003358:Cosmetics; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D008543:Melanins; D013739:Testosterone; D014442:Monophenol Monooxygenase; D005003:Ethisterone