title: New oxidized sterols from Aspergillus awamori and the endo-boat conformation adopted by the cyclohexene oxide system.
abstract: Two new oxidized sterols 1 and 2 were obtained from the active fraction of a mangrove fungus Aspergillus awamori isolated from the soils around the mangrove plant Acrostichum speciosum. Their structures were elucidated using spectroscopic methods as 22E-7alpha-methoxy-5alpha,6alpha-epoxyergosta-8(14),22-dien-3beta-ol (1) and 22E-3beta-hydroxy-5alpha,6alpha,8alpha,14alpha-diepoxyergosta-22-en-7-one (2). The NMR data and complete assignments for both DMSO-d(6) and CDCl(3) were given. Their cytotoxic activity against A549 cell line was evaluated. Furthermore, the detailed conformation analysis for ring B (cyclohexene oxide system) of sterol 1 was given on the basis of NOEs. The endo-boat conformation was considered as the preferred conformation for ring B rather than half-chair conformation.
authors.affiliation: Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Gao
authors.forename: Kui
authors.initials: K
authors.lastname: Hong
authors.forename: Guo-Dong
authors.initials: GD
authors.lastname: Chen
authors.forename: Chuan-Xi
authors.initials: CX
authors.lastname: Wang
authors.forename: Jin-Shan
authors.initials: JS
authors.lastname: Tang
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Miao-Miao
authors.initials: MM
authors.lastname: Jiang
authors.forename: Man-Mei
authors.initials: MM
authors.lastname: Li
authors.forename: Nai-Li
authors.initials: NL
authors.lastname: Wang
authors.forename: Xin-Sheng
authors.initials: XS
authors.lastname: Yao
mesh_terms: D001230:Aspergillus / Q000737:chemistry*; D053138:Cyclohexenes / Q000737:chemistry*; D004875:Ergosterol / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D013237:Stereoisomerism; D013261:Sterols / Q000737:chemistry / Q000302:isolation & purification
chemical_list: C547441:22E-3beta-hydroxy-5alpha,6alpha,8alpha,14alpha-diepoxyergosta-22-en-7-one; D053138:Cyclohexenes; D013261:Sterols; C007193:cyclohexene oxide; D004875:Ergosterol