Cyclohexadepsipeptides of the Isaridin Class from the Marine-Derived Fungus Beauveria felina EN-135

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• 作者：Feng-Yu Du ; Peng Zhang ; Xiao-Ming Li ; Chun-Shun Li ; Chuan-Ming Cui ; Bin-Gui Wang
• 刊名：Journal of Natural Products
• 出版年：2014
• 出版时间：May 23, 2014
• 年：2014
• 卷：77
• 期：5
• 页码：1164-1169
• 全文大小：339K
• 年卷期：v.77,no.5(May 23, 2014)
• ISSN：1520-6025

文摘

Three new cyclohexadepsipeptides of the isaridin class including isaridin G (1), desmethylisaridin G (2), and desmethylisaridin C1 (3), along with three related known metabolites (4鈥?b>6), were isolated and identified from the marine bryozoan-derived fungus Beauveria felina EN-135. The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis, and the structures and absolute configurations of compounds 1鈥?b>3 were confirmed by single-crystal X-ray diffraction analysis. The crystal structures showed the presence of 尾-turns for the Tyr³/N-Me-Val⁴ and Phe³/N-Me-Val⁴ amide bonds in compounds 2 and 3, respectively, in the cis conformations, which were opposite other reported isaridins. The conformations of the HMPA¹-Pro² amide bond in compound 2 are different in the solution and in the crystal structures, which showed trans and cis geometries, respectively, while compounds 1 and 3 do not exhibit this phenomenon. Each of the isolated compounds was evaluated for antimicrobial activity and brine shrimp lethality. Compound 3 exhibited antibacterial activity against E. coli with an MIC value of 8 渭g/mL.