title: Microbial hydroxylation of bufalin by Cunninghamella blakesleana and Mucor spinosus.
abstract: The microbial transformation of a cytotoxic bufadienolide, bufalin (1), was carried out using two strains of filamentous fungi. Cunninghamella blakesleana catalyzed the specific 12alpha-hydroxylation of bufalin and produced 12alpha-hydroxybufalin (2) and 7beta,12alpha-dihydroxybufalin (3) as the major metabolites, together with 7beta-hydroxybufalin (4) and 12beta-hydroxybufalin (5) in low yields. Two minor products were isolated from the culture broth of Mucor spinosus and were identified as 7beta,15alpha-dihydroxybufalin (6) and 5beta,7beta-dihydroxybufalin (7), respectively. Metabolites 2, 3, 6, and 7 are new compounds, and their structures were fully characterized by NMR and MS spectroscopy.
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xueyuan Road 38, Beijing 100083, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Ye
authors.forename: Jian
authors.initials: J
authors.lastname: Han
authors.forename: Guangzhong
authors.initials: G
authors.lastname: Tu
authors.forename: Dongge
authors.initials: D
authors.lastname: An
authors.forename: Dean
authors.initials: D
authors.lastname: Guo
mesh_terms: D001711:Biotransformation; D002018:Bufanolides / Q000737:chemistry* / Q000378:metabolism; D002770:Cholenes / Q000737:chemistry* / Q000378:metabolism; D046508:Culture Techniques; D020093:Cunninghamella / Q000378:metabolism*; D006900:Hydroxylation; D013058:Mass Spectrometry; D015394:Molecular Structure; D009089:Mucor / Q000378:metabolism*; D009183:Mycotoxins / Q000737:chemistry* / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular
chemical_list: D002018:Bufanolides; D002770:Cholenes; D009183:Mycotoxins; C087925:bufadienolide; C022777:bufalin