A biological evaluation in the series of 5-cinnamoyl-6-aminouracils has been undertaken. These compounds have been found to be in an extended planar conformation fitting well with a possible stacking interaction between the nucleic bases of DNA; thus an eventual anticancer activity by intercalation could be hoped. 1, 3-Dimethyl-5-cinnamoyl-6-aminouracil was found to be active when administered ip against ip-implanted P388 leukemia in vivo ( ...