Antitumor Alkaloids in Callus Cultures of Cephalotaxus Harringtonia

Leaves and stems of CephalolaxlIs harringlonia were induced to callus on Murashige and Skoog medium supplemented with additional vitamins, hypoxanthine, naphthaleneacetic acid and kinetin. Analysis by GC-MS showed cephalotaxine and its antitumor esters (harringtonine, isoharringtonine and homoharringtoninel in both callus and medium, whereas deoxyharringtonine was present (in relatively large amounts) only in the medium. The amount of each alkaloid was 2 to 6 times greater at 6 months than at 3 months except for deoxyharringtonine, which was not increased. At 6 months, the total alkaloid production was 1-3';1~ of levels reported for mature trees, but the pattern was the same: 60 %cephalotaxine, 40 %esters. The pattern of the parent plant was unique (5 ~~ cephalotaxine, 80';l~ homoharringtonine, 15% other esters) and may more accurately represent that of fresh plant material. A new cephalotaxine ester, homodeoxyharringtonine, was also detected in the culture medium.