A new pyrrole alkaloid from the roots of Cissampelos pareira.

Phytochemical investigation of the roots of Cissampelos pareira Linn. led to the isolation of one new pyrrole alkaloid, cissampeline (1), together with ten known alkaloids, (-)-curine (2), (-)-cyclanoline (3), (+)-tetrandrine (4), (+)-obaberine (5), (+)-obamegine (6), (-)-oblongine (7), (+)-homoaromoline (8), (-)-nor-N׳-chondrocurine (9), trans-N-feruloyltyramine (10) and (+)-coclaurine (11). Their structures were elucidated by extensive NMR and MS spectroscopic analyses. Interestingly, compound 1 represents the first example of pyrrole alkaloid found in the genus Cissampelos. Moreover, compounds 5-11 were isolated for the first time from this genus. Among them, compound 6 showed the highest anti-acetylcholinesterase activity with an IC₅₀ value of 3.26 µM, whereas compound 8 displayed the most potent cytotoxicity against human colon cancer (HT29) cells with an IC₅₀ value of 7.89 µM.