摘要

A novel mononuclear platinum(II) complex, [PtL(DMSO)Cl]Cl (1, here L = danysl bis(2-benzothiazolyl-methyl)amine), has been synthesized and characterized by ESI-MS, IR spectrum, H-1 NMR, C-13 NMR, molar conductivity, and elemental analysis. The results suggest that in the structure of complex 1, a platinum(II) ion is coordinated by a tertiary amine nitrogen, a benzothiazole nitrogen, a DMSO sulfur, and an exogenous chlorine ion to form one square mononuclear structure. Complex 1 exhibits a cytotoxicity comparable to that of cisplatin against HeLa cell line and more potent activities against A-549 and MCF-7 cell lines. Compared to those of L, the potent cytotoxicity of 1 should result from the coordination of Pt(II). DNA binding experiments demonstrate that 1 could strongly bind to calf thymus DNA (CT-DNA) by a groove binding mode accompanied with a moderate intercalation and induce a visible conformational variation of DNA. Investigation of the reaction of 1 with 5'-GMP by ESI-MS shows that complex 1 could first form a 1:1 adduct [PtL(DMSO)(GMP) - 2Na + H](+) with 5'-GMP and react further with a second equivalent of 5'-GMP to form a 1:2 adduct [PtL(DMSO)(GMP)(2) - 4Na + 3H](+), which is similar to those of [Pt(en)(DMSO)Cl]Cl and cisplatin. Therefore, the anticancer mechanism of these compounds might well be related to each other. The evalution of the protein binding ability shows that complex 1 could bind to human serum albumin (HSA) with a moderate binding affinity, quench the intrinsic fluorescence of HSA, and destroy the tertiary structure of HSA.