New oxidized sterols from Aspergillus awamori and the endo-boat conformation adopted by the cyclohexene oxide system (pages 38–43)
Hao Gao, Kui Hong, Guo-Dong Chen, Chuan-Xi Wang, Jin-Shan Tang, Yang Yu, Miao-Miao Jiang, Man-Mei Li, Nai-Li Wang and Xin-Sheng Yao
Version of Record online: 28 OCT 2009 | DOI: 10.1002/mrc.2536
Two new oxidized sterols (22E-7α-methoxy-5α,6α-epoxyergosta-8(14),22-dien-3β-ol (1) and 22E-3β-hydroxy-5α,6α,8α,14α-diepoxyergosta-22-en-7-one (2)) were obtained from a mangrove fungus Aspergillus awamori. The NMR data and complete assignments for both DMSO-d6 and CDCl3 were given and 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 based on the NOEs. The endo-boat conformation was considered as the preferred conformation for ring B rather than half-chair conformation.