<i>N1,N2,N3</i>-Trisisopentenyl Guanidine and N1,N2-Diisopentenyl Guanidine, Two Cytotoxic Alkaloids from <i>Alchornea Cordifolia</i> (Schumach. &amp; Thonn.) Müll. Arg. (Euphorbiaceae) Root Barks

Abstract

This paper describes the purification of two guanidine alkaloids: N1, N2-diisopentenyl guanidine (DIPG) 1 and N1,N2,N3-triisopentenyl guanidine (TIPG) 2 from Alchornea cordifolia root bark and reports their cytotoxic properties on cancer (HeLa, Mel-5, J774) and non cancer (WI 38) cells. TIPG showed the highest cytotoxicity with IC 50 values from 0.7 to 14.3 μg/mL (2.6 to 54.3 μM) on the four cell lines while DIPG was much less active: IC 50 45.8 and 97.6 μg/mL (234.8 and 500.5 μM) on Mel-5 and HeLa and &gt; 512.8 μM on J774 and WI 38. The results indicate that the cytotoxicity notably decreased with the loss of one isopentenyl substituent.