title: Three new and eleven known unusual C25 steroids: activated production of silent metabolites in a marine-derived fungus by chemical mutagenesis strategy using diethyl sulphate.
abstract: Three new (1-3) and 11 known (4-14) C25 steroids with an unusual bicyclo[4.4.1]A/B ring system were isolated by tracing newly produced metabolites in the EtOAc extract of an antitumor mutant AD-1-2 obtained by the diethyl sulphate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. HPLC-PDAD-UV and HPLC-ESI-MS analyses indicated that the G59 strain did not produce these metabolites and the production of 1-14 in the mutant AD-1-2 extract was caused by the activation of silent metabolites in the original G59 strain by DES mutagenesis. The structures of the new compounds, named antineocyclocitrinols A (1) and B (2) and 23-O-methylantineocyclocitrinol (3), including their absolute configurations were determined by various spectroscopic methods, especially the NMR and Mo2-induced CD analyses. Compounds 1-3 provide the first examples of the C25 bicyclo[4.4.1]A/B ring steroids with the Z-configuration of 20,22-double bond. All of 1-14 weakly inhibited several human cancer cell lines to varying extents. These results provided additional examples for the successful application of the chemical mutagenesis strategy using DES to discover new compounds by activating silent metabolites in fungal isolates and supported also the effectiveness and usefulness of this new strategy.
authors.affiliation: Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China. sdrlcw@126.com.
authors.forename: Ming-Wen
authors.initials: MW
authors.lastname: Xia
authors.affiliation: Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China. cuicb@sohu.com.
authors.forename: Cheng-Bin
authors.initials: CB
authors.lastname: Cui
authors.affiliation: Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China. sdrlcw@126.com.
authors.forename: Chang-Wei
authors.initials: CW
authors.lastname: Li
authors.affiliation: Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China. sdrlcw@126.com.
authors.forename: Chang-Jing
authors.initials: CJ
authors.lastname: Wu
mesh_terms: D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D006801:Humans; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D016296:Mutagenesis / Q000187:drug effects*; D009153:Mutagens / Q000494:pharmacology*; D010407:Penicillium / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D013256:Steroids / Q000737:chemistry* / Q000378:metabolism; D013463:Sulfuric Acid Esters / Q000494:pharmacology*
chemical_list: D007202:Indicators and Reagents; D009153:Mutagens; D013256:Steroids; D013463:Sulfuric Acid Esters; C011612:diethyl sulfate