Through a systematic modification of the novel angiogenesis inhibitor 4-senecioyloxymethyl- 6, 7-dimethoxycoumarin (1) we found that a 6, 7-dimethoxy moiety is important for bioactivity of 1. Replacement of the lactone functionality in coumarin 1 by an amide decreased its activity. By substitution of the senecioyl chain with various cinnamoyl groups we discovered 6d, bearing a 4-methoxycinnamoyl instead of senecioyl side chain, with inhibitory activity ...
