Acremosides A–G, Sugar Alcohol-Conjugated Acyclic Sesquiterpenes from a Sponge-Derived <i>Acremonium</i> Species
Xiaomeng Hao, Shasha Li, Jianrui Li, Guiyang Wang, Jiao Li, Zong‐Gen Peng, Maoluo Gan
Abstract
Seven new sugar alcohol-conjugated acyclic sesquiterpenes, acremosides A–G ( 1 – 7 ), were isolated from the cultures of the sponge-associated fungus Acremonium sp. IMB18-086 cultivated with heat-killed Pseudomonas aeruginosa . The structures were determined by comprehensive analyses of 1D and 2D NMR spectroscopic data. The relative configurations were established by J -based configuration analysis and acetonide derivatization. The absolute configurations were elucidated by the Mosher ester method and ECD calculations. The structures of acremosides E–G ( 5 – 7 ) featured the linear sesquiterpene skeleton with a tetrahydrofuran moiety attached to a sugar alcohol. Acremosides A ( 1 ) and C–E ( 3 – 5 ) showed significant inhibitory activities against hepatitis C virus (EC 50 values of 4.8–8.8 μM) with no cytotoxicity (CC 50 of >200 μM).