[摘要]：The synthesis and the X-ray structure of 16a-thiocamptothecin (TCPT; I), the thiopyridone analog of camptothecin (CPT), are accomplished. The crystal contains two structurally identical, yet independent mols. Both of them are connected to other mols. via two intermol. hydrogen bonds. S-Methylation of TCPT leads to the cleavage of the C-ring. The cytotoxic activity of TCPT was evaluated against different human tumor cell lines using CPT as ref. compd.
