N1,N2,N3-Trisisopentenyl guanidine and N1,N2-Diisopentenyl guanidine, two cytotoxic alkaloids from Alchornea cordifolia (Schumach.& Thonn.) Mull. Arg. (Euphorbiaceae) root barks

This paper describes the purification of two guanidine alkaloids: NI, N2-diisopentenyl guanidine (DIPG) 1 and NI,N2,N3-trilsopentenyl guanidine (TIPG) 2 from Alchornea cordifolia root bark and reports their cytotoxic properties on cancer (HeLa, Me]-5, J774) and non cancer (WI 38) cells. TIPG showed the highest cytotoxicity with IC50 values from 0.7 to 14.3 mu g/mL (2.6 to 54.3 mu M) on the four cell lines while DIPG was much less active: IC50 45.8 and 97.6 mu g/mL (234.8 and 500.5 mu M) on Mel-5 and HeLa and > 512.8 mu M on J774 and WI 38. The results indicate that the cytotoxicity notably decreased with the loss of one isopentenyl substituent