The synthesis of new isogranulatimide analogues, their inhibitory activities toward the Checkpoint 1 kinase (Chk1), and their in vitro cytotoxicities toward four tumor cell lines (one murine L1210 leukemia, and three human cell lines: DU145 prostate carcinoma, A549 non- small cell lung carcinoma, and HT29 colon carcinoma) are described. The affinity for DNA of some representative compounds and their ability to induce DNA cleavage mediated by ...