SITES OF ACCUMULATION OF THE ANTITUMOR ALKALOID CAMPTOTHECIN IN CAMPTOTHECA-ACUMINATA

Camptothecin is an anticancer and antiviral alkaloid produced by the C hinese tree Camptotheca acuminata (Nyssaceae). Despite previous report s of low levels of anticancer activity in leaves of Camptotheca acumin ata, we have discovered that camptothecin accumulates to approximately 0.4% of the dry weight of young leaves. This level is 1.5-fold higher than that of the seeds and 2.5-fold higher than that of the bark, the two currently used sources of the drug. As the leaves mature, the con centration and absolute amount of camptothecin decreases rapidly. The high levels of canaptothecin in young leaves could provide an easily h arvested, non-destructive source of this important drug.