New Steryl Esters of Fatty Acids from the Mangrove Fungus Aspergillus awamori

✍ Scribed by Hao Gao; Kui Hong; Xue Zhang; Hong-Wei Liu; Nai-Li Wang; Ling Zhuang; Xin-Sheng Yao

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: German
• Weight: 134 KB
• Volume: 90
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200790116

✦ Synopsis

Abstract

The polyhydroxylated ergostane‐type sterol 9, its derivatives 10–15, and the fatty acid esters 1–8 were isolated from a fungus strain which was collected from mangrove areas at Wenchang, Hainan Province, P. R. China, exhibited potent cytotoxic activity, and was identified as Aspergillus awamori. The structures of 1–15 were elucidated by spectroscopic and chemical methods. Among them, the six steryl esters 1–6 of fatty acids were new compounds, i.e., (3__β__,5__α__,6__α__,22__E__)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐palmitate (1), (3__β__,5__α__,6__α__,22__E__)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐stearate (2), (3__β__,5__α__,6__α__,22__E__)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐oleate (3), (3__β__,5__α__,6__α__,22__E__)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐linoleate (4), (3__β__,5__α__,6__β__,22__E__)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐palmitate (5), and (3__β__,5__α__,6__β__,22__E__)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐stearate (6). The related known fatty acids stearic acid (=octadecanoic acid) and palmitic acid (=octadecanoic acid) were also obtained. A speculative biogenetic relationship of the metabolites is proposed. The known polyhydroxylated sterols and derivatives showed cytotoxic activities, in agreement with earlier reports. The cytotoxic activities against B16 and SMMC‐7721 cell lines of the new steryl esters 1–6 by the MTT method were weak.