Ejima A, Terasawa H, Sugimori M, Ohsuki S, Matsumoto K, Kawato Y, Tagawa H
Chem Pharm Bull (Tokyo). 1989 Aug;37(8):2253-5. doi: 10.1248/cpb.37.2253.
The camptothecin analogues (+-)-7-ethyl-10-methoxy-20-deoxyaminocamptothecin (2) and (+-)-7-ethyl-10-hydroxy-20-deoxyaminocamptothecin.HCl (3) were synthesized from indolizine compound 4 via Friedländer condensation to construct a pentacyclic ring system, and were tested in a P388 mouse antileukemia assay. Compounds 2 and 3 were more active and less toxic than (+)-camptothecin (1), and therefore had higher therapeutic ratios.
