[Studies on semi-synthesis of cephalotaxine esters and correlation of their structures with antitumor activity]

: Ten esters of cephalotaxine with amino acids possessing widely different structural features have been synthesized and tested for antitumor activity. Preliminary data showed that compound 6 is the most active one. However, it is still less potent than harringtonine. Other synthetic esters possess varying activities at 10 micrograms/ml. Preliminary structure activity relationship of these esters was discussed.