[Studies on the alkaloids of Cephalotaxus. IX. Semi-synthesis of cephalotaxine esters and their anti-leukemic activity]

Harringtonine, homoharringtonine, deoxyharringtonine and isoharringtonine isolated from Cephalotaxus plant are the esters of cephalotaxine with significant inhibitory activity against P-388 leukemia. In this investigation seventeen new esters of cephalotaxine type Alkaloids have been synthesized. Preliminary pharmacological examination showed that compounds 1, 2, 2 + 3, 6 and 8 showed similar antileukemic activity as homoharringtonine. Compounds 4, 5, 15 and 16 showed moderate inhibitory activity. Some structure activity correlations of these esters were discussed.