Bioactive Coumarins from the Stems of Clausena emarginata.

Five new coumarins, clauemarmarins I - M (1 - 4), together with 10 known analogs (5 - 14), were isolated from the stems of Clausena emarginata. Compounds 8 - 13 were obtained from this plant for the first time. Their structures were established and elucidated by comprehensive analysis of spectroscopic data. The absolute configurations of 1 - 4 were further determined by their electronic circular dichroism spectroscopy. Compounds 5, 7, 12, and 14 exhibited inhibitory effects on LPS-induced NO production. Compounds 5 - 7 showed selective neuroprotective effects in Aβ model at 10 μm.