New oxidized sterols from Aspergillus awamori and the endo-boat conformation adopted by the cyclohexene oxide system.
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.
Gao
Hao
H
Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China.
Hong
Kui
K
Chen
Guo-Dong
GD
Wang
Chuan-Xi
CX
Tang
Jin-Shan
JS
Yu
Yang
Y
Jiang
Miao-Miao
MM
Li
Man-Mei
MM
Wang
Nai-Li
NL
Yao
Xin-Sheng
XS
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
C547441:22E-3beta-hydroxy-5alpha,6alpha,8alpha,14alpha-diepoxyergosta-22-en-7-one; D053138:Cyclohexenes; D013261:Sterols; C007193:cyclohexene oxide; D004875:Ergosterol