Identification of Oxaphenalenone Ketals from the Ascomycete Fungus Neonectria sp----中国科学院微生物研究所

科研成果

论文题目:	Identification of Oxaphenalenone Ketals from the Ascomycete Fungus Neonectria sp
作者:	Ren Jinwei, Niu Shubing, Li Li, Geng Zhufeng, Liu Xingzhong, and Che Yongsheng*.
联系作者:
刊物名称:	J Nat Prod
期:
卷:
页:
年份:	2015
影响因子:	3.395
论文下载:	http://pubs.acs.org/doi/abs/10.1021/acs.jnatprod.5b00159
摘要:	Neonectrolides B-E (4-7), four new oxaphenalenone ketals incorporating the new furo[2,3-b]isochromeno[3,4,5-def]chromen-11(6aH)-one skeleton, were isolated from the fermentation extract of the ascomycete fungus Neonectria sp. in an in-depth investigation guided by HPLC fingerprint and a cytotoxicity assay. The previously identified oxaphenalenone spiroketal neonectrolide A (1) and its putative biosynthetic precursors (2 and 3) were also reisolated in the current work. The structures of 4-7 were primarily elucidated by interpretation of NMR spectroscopic data, and the absolute configurations were deduced by electronic circular dichroism calculations. Compound 6 showed cytotoxic effects against four of the six human tumor cell lines tested. Biosynthetically, compounds 4-7 could be derived via the Diels-Alder reaction cascades starting from derivatives of the co-isolated metabolites 2 and 3.