Isostrychnopentamine, an indolomonoterpenic alkaloid from Strychnos usambarensis, induces cell cycle arrest and apoptosis in human colon cancer cells. - Frederich,M.; Bentires-Alj,M.; Tits,M.; Angenot,L.; Greimers,R.; Gielen,J.; Bours,V.; Merville,M.P. (J Pharmacol Exp Ther, 2003)