Spartinoxide, a new enantiomer of A82775C with inhibitory activity toward HLE from the marine-derived fungus Phaeosphaeria spartinae

摘要

The fungus Phaeosphaeria spartinae is an endophyte of the marine alga Ceramium sp. Investigation of this marine-derived fungus led to the isolation of spartinoxide (1), which is the enantiomer of the known compound A82775C (2). Additionally, the known metabolites 4-hydroxy-3-prenyl-benzoic acid (4) and anofinic acid (5) were obtained. The structures of all compounds were established from extensive spectroscopic investigations. Compounds 1, 4 and 5 were assayed against the enzymes human leukocyte elastase (HLE), trypsin, acetylcholinesterase and cholesterolesterase. Compounds 1 and 4 showed potent inhibition of HLE with IC_(50) values of 1.71 ± 0.30 μg/mL (6.5 μM) and 1.67 ± 0.32 μg/mL (8.1 μM), respectively.