title: Microbial transformations of isosteviol.
abstract: Microbial transformations of the tetracyclic diterpenoid isosteviol (ent-16-ketobeyeran-19-oic acid) (2) have revealed that isosteviol is metabolized by Cunninghamella bainieri, Actinoplanes sp., Mucor recurvatus, and Cunninghamella blakesleeana to yield five new metabolites, ent-11alpha,12alpha-dihydroxy-16-ketobeyeran-19-oic acid (5), ent-11alpha,12alpha,17-trihydroxy-16-ketobeyeran-19-oic acid (6), ent-12alpha,15alpha-dihydroxy-16-ketobeyeran-19-oic acid (7), ent-7alpha,15alpha-dihydroxy-16- ketobeyeran-19-oic acid (8), and ent-9alpha-hydroxy-16-ketobeyeran-19-oic acid (9), together with three known metabolites, ent-7alpha-hydroxy-16-ketobeyeran-19-oic acid (3), ent-7beta-hydroxy-16-ketobeyeran-19-oic acid (4), and ent-12alpha-hydroxy-16-ketobeyeran-19-oic acid (10). The structures of these metabolites were established on the basis of HRFABMS and 1D and 2D NMR spectral data. In addition, metabolites 3-10 were tested for antihypertensive activity and were found to be less active than the parent compound 2.
authors.affiliation: Graduate Institute of Pharmaceutical Sciences, Taipei Medical University, Taipei, Taiwan 110, Republic of China.
authors.forename: Feng-Lin
authors.initials: FL
authors.lastname: Hsu
authors.forename: Chia-Chung
authors.initials: CC
authors.lastname: Hou
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Yang
authors.forename: Juei-Tang
authors.initials: JT
authors.lastname: Cheng
authors.forename: Tzong-Cherng
authors.initials: TC
authors.lastname: Chi
authors.forename: Pang-Chun
authors.initials: PC
authors.lastname: Liu
authors.forename: Shwu-Jiuan
authors.initials: SJ
authors.lastname: Lin
mesh_terms: D000959:Antihypertensive Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001711:Biotransformation; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045786:Diterpenes, Kaurane; D005658:Fungi / Q000378:metabolism*; D006868:Hydrolysis; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
chemical_list: D000959:Antihypertensive Agents; D004224:Diterpenes; D045786:Diterpenes, Kaurane; C012042:steviol