Analogs of camptothecin

Abstract
Several compounds having portions of the camptothecin ring system were prepared. These compounds were screened against L1210 lymphoid leukemia with negative results. Two of the analogs which contained the pyridine and hydroxylactone D and E rings were also screened for inhibition of DNA and RNA syntheses in HeLa cells. Each of these analogs had decreased activity as compared with comptothecin and there was no degradation of DNA in the HeLa cells. This suggest that the D and E rings are not a sufficient requirement for camptothecin-like activity.