Annosquacin A (1) (23 mg) was isolated as a white powder and gave a molecular formula of C35H62O6 as deduced from HRESIMS at m/z 601.4482 [M+Na]+ (calcd. 601.4444) and 579.4653 [M+H]+ (calcd. 579.4625), indicating the presence of five degrees of unsaturation. The IR absorptions at 3416 and 1751 cm-1.