STUDIES ON THE ALKALOIDS OF CEPHALOTAXUS Ⅶ.STRUCTURS AND SEMI-SYNTHESIS OF TWO ANTICANCER CEPHALOTAXINE ESTERS

Two new alkaloids, namely neoharringtonine (1) and anhydro-harringtonine (2) with significant antileukemic activity were isolated from Cephalotaxusfortunei Hook f..Their structures have been established by spectral analyses and semi-synthesis. Seven known alkaloids,deoxyharringtonine(3), isoharringtonine(4), isocephalo-taxinone (5), acetylcephalotaxine(6), cephalotaxine(7), harringtonine(8) andhomoharringtonine (9), were also isolated and identified.