title: Biotransformation of 20(S)-protopanaxadiol by Mucor spinosus.
abstract: Biotransformation of 20(S)-protopanaxadiol (1) by the fungus Mucor spinosus AS 3.3450 yielded eight metabolites (2-9). On the basis of NMR and MS analyses, the metabolites were identified as 12-oxo-15alpha,27-dihydroxyl-20(S)-protopanaxadiol (2), 12-oxo-7beta,11alpha,28-trihydroxyl-20(S)-protopanaxadiol (3), 12-oxo-7beta,28-dihydroxyl-20(S)-protopanaxadiol (4), 12-oxo-15alpha,29-dihydroxyl-20(S)-protopanaxadiol (5), 12-oxo-7beta,15alpha-dihydroxyl-20(S)-protopanaxadiol (6), 12-oxo-7beta,11beta-dihydroxyl-20(S)-protopanaxadiol (7), 12-oxo-15alpha-hydroxyl-20(S)-protopanaxadiol (8), and 12-oxo-7beta-hydroxyl-20(S)-protopanaxadiol (9), respectively. Among them, 2-5, 7, and 8 are new compounds. These results indicated that M. spinosus could catalyze the specific C-12 dehydrogenation of 20(S)-protopanaxadiol, as well hydroxylation at different positions. These biocatalytic reactions may be difficult for chemical synthesis. The biotransformed products showed weak in vitro cytotoxic activities.
authors.affiliation: Division of Pharmacognostical Biotechnology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Huifeng
authors.initials: H
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Ye
authors.forename: Hongzhu
authors.initials: H
authors.lastname: Guo
authors.forename: Yin
authors.initials: Y
authors.lastname: Tian
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhou
authors.forename: Yuchi
authors.initials: Y
authors.lastname: Hu
authors.forename: Dean
authors.initials: D
authors.lastname: Guo
mesh_terms: D055162:Biocatalysis; D001711:Biotransformation; D045744:Cell Line, Tumor; D006801:Humans; D007938:Leukemia / Q000188:drug therapy*; D015394:Molecular Structure; D009089:Mucor / Q000378:metabolism*; D005894:Panax / Q000737:chemistry*; D008517:Phytotherapy; D010936:Plant Extracts / Q000378:metabolism* / Q000627:therapeutic use; D012502:Sapogenins / Q000378:metabolism* / Q000627:therapeutic use
chemical_list: D010936:Plant Extracts; D012502:Sapogenins; C062916:protopanaxadiol