B-Ring-Aryl Substituted Luotonin A Analogues with a New Binding Mode to the Topoisomerase 1-DNA Complex Show Enhanced Cytotoxic Activity
Figure 5
DNA relaxation inhibition assay.
Drug concentration was 10 µM. Activities are expressed relative to that of camptothecin (CPT): (+) 1–25%, (++) 26–50%, (+++) 51–75%, (++++) 76–100% of the CPT inhibition. All compounds were at least as potent as luotonin A and compound 3g showed a remarkable activity, comparable to that of camptothecin.