Synthesis, interaction with DNA and bovine serum albumin of the transition metal complexes of demethylcantharate and 2-aminobenzothiazole.

Four new transition metal complexes (Habtz)(2)[M(DCA)(2)]·6H(2)O (M=Co(II) (1), Ni(II) (2), Cu(II) (3), Zn(II) (4); DCA=demethylcantharate, 7-oxabicyclo [2.2.1]heptane-2,3-dicarboxylate, C(8)H(8)O(5); Habtz=2-aminobenzothiazole acid, C(7)H(7)N(2)S) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra and thermogravimetric analysis. The coordination number of complex was six. The X-ray diffraction analysis indicated that complex 3 crystallized in the triclinic crystal system with P1¯ space group. The DNA-binding properties of the complexes were investigated by electronic absorption spectra, fluorescence spectra, viscosity measurements. Title complexes could bind to DNA via partial intercalative mode. The K(b) of the complexes were 5.33×10(4) (1), 7.04×10(4) (2), 9.91×10(4) (3) and 5.03×10(4) L mol(-1) (4). The results of agarose gel electrophoresis showed that Cu(II) complex could cleave pBR322 plasmid DNA via radical-based mechanism. The complexes could quench the intrinsic fluorescence of bovine serum albumin (BSA) through a static quenching with the binding constants K(a) of 1.11×10(4) (1), 1.24×10(6) (2), 8.42×10(5) (3) and 1.75×10(4) L mol(-1) (4). The complexes had intense antiproliferative activities against human hepatoma cell lines (SMMC7721) and human gastric cancer cells (MGC80-3) lines in vitro. Cu(II) complex had the strongest activity against human gastric cancer cells. Crown