8 R -methoxy-9 R -hydroxyl-fumitremorgin C, a new diketopiperazine alkaloid from Haima cold seep-derived fungus Aspergillus fumigatus CYH-5.

One novel diketopiperazine derivative 8 R -methoxy-9 R -hydroxyl-fumitremorgin C ( 1 ), together with twelve known compounds, was separated from the fungus Aspergillus fumigatus CYH-5 collected from Haima cold seep. The structures of the compounds were identified by NMR, MS, optical rotation, hydrolysis reaction and comparing with literatures. Among them, compounds 10 and 11 exhibited inhibitory effect against bacteria. Compound 11 showed inhibitory activity on α -glucosidase and compound 8 displayed acetylcholinesterase (AchE) inhibitory activity.