Hk. Wang et al., THE SYNTHESIS OF 5-SUBSTITUTED CAMPTOTHECINS AS POTENTIAL INHIBITORS OF DNA TOPOISOMERASE-I, Bioorganic & medicinal chemistry letters, 5(1), 1995, pp. 77-82
Four new 5-substituted camptothecins (4-7) have been synthesized and e
valuated for DNA topoisomerase I inhibition. The results suggested tha
t the pyridone moiety in the D ring of camptothecin plays a crucial ro
le in determining its activity and that the 5 position of the C ring s
hould be unsubstituted for retention of activity.