title: Hydroxylation of diosgenin by Absidia coerulea.
abstract: Microbial transformation of diosgenin (1) using Absidia coerulea yielded five new polar metabolites, which were identified as (25R)-spirost-5-en-3 beta,7 beta,12 beta,25 alpha-tetrol (2), (25S)-spirost-5-en-3 beta,7 alpha,12 beta,25 beta-tetrol (3), (25S)-spirost-5-en-3 beta,7 beta,12 beta,25 beta-tetrol (4), (25R)-spirost-5-en-3 beta,7 alpha,12 beta,25 alpha-tetrol (5), and (25R)-spirost-5-en-3 beta,7 beta,12 beta,24 beta-tetrol (6). Their structures were established on the basis of mass spectrometry and multi-dimensional NMR spectroscopy. The characteristic transformations observed were C-7 alpha, C-7 beta, C-12 beta, C-24 beta, C-25 alpha, and C-25 beta hydroxylation. The cytotoxicity of compounds 1-6 was evaluated against the human myelogenous leukemia K562 cell line and squamous cell carcinoma KB parental cell lines. Compounds 2-6 exhibited weak cytotoxicity against K562 and KB cells and were less potent than the parent compound 1.
authors.affiliation: Department of Natural Products Chemistry, School of Pharmaceutical Sciences, Shandong University, No. 44 West Wenhua Road, Jinan 250012, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Ling-Mei
authors.initials: LM
authors.lastname: Sun
authors.forename: Xiao-Ning
authors.initials: XN
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Shen
authors.forename: Mei
authors.initials: M
authors.lastname: Ji
authors.forename: Hong-Xiang
authors.initials: HX
authors.lastname: Lou
mesh_terms: D020095:Absidia / Q000737:chemistry / Q000378:metabolism*; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology; D001711:Biotransformation; D002240:Carbohydrate Sequence; D004396:Coloring Agents; D004144:Diosgenin / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D006900:Hydroxylation; D007202:Indicators and Reagents; D020014:K562 Cells; D007624:KB Cells; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004396:Coloring Agents; D007202:Indicators and Reagents; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue; D004144:Diosgenin