title: Microbiological transformation of the triterpene nigranoic acid by the freshwater fungus Dictyosporium heptasporum.
abstract: The microbiological transformation of the triterpene nigranoic acid (3,4-secocycloarta-4(28),24(Z)-diene-3,26-dioic acid) (1) to 3,4-secocycloarta-4(28),17(20),24(Z)-triene-7β-hydroxy-16β,26-lactone-3-oic acid (2) and 3,4-secocycloarta-4(28),17(20)(Z),24(Z)-triene-7β-hydroxy-16β-methoxy-3,26-dioic acid (3) by the freshwater fungus Dictyosporium heptasporum YMF1.01213 has been demonstrated. The structures of the biotransformation products were determined by spectroscopic and MS analyses. Compound 2, characterized by the presence of a formed C-16/C-26 ester bridge, provided a novel nine-membered lactone ring structural skeleton for 3,4-secocycloartane triterpenoid derivatives. In addition, Compounds 1-3 exhibited weak anti-HIV activity in vitro. Compounds 2 and 3 were reported for the first time as natural product derivatives.
authors.affiliation: School of Life Science, Southwest University, Chongqing 400715, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Sun
authors.forename: Hong-Chuan
authors.initials: HC
authors.lastname: Song
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Yang
authors.forename: Pan
authors.initials: P
authors.lastname: Yang
authors.forename: Dong-Yan
authors.initials: DY
authors.lastname: Yang
authors.forename: Kai-Ze
authors.initials: KZ
authors.lastname: Shen
authors.forename: Yao-Bo
authors.initials: YB
authors.lastname: Xu
authors.forename: Yan-Xiu
authors.initials: YX
authors.lastname: Gao
authors.forename: Ye-Gao
authors.initials: YG
authors.lastname: Chen
authors.forename: Jin-Yan
authors.initials: JY
authors.lastname: Dong
mesh_terms: D019380:Anti-HIV Agents / Q000737:chemistry / Q000378:metabolism*; D001711:Biotransformation; D005618:Fresh Water / Q000382:microbiology; D005658:Fungi / Q000378:metabolism*; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D014315:Triterpenes / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D019380:Anti-HIV Agents; D014315:Triterpenes; C100860:nigranoic acid