Abstract
A new cobalt(II) complex, [Co(C3H4N2)(C8H8O5)(H2O)2]·2H2O, of demethylcantharate(7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, C8H8O5) with imidazole has been synthesized from cobalt chloride, demethylcantharidin (NCTD) and imidazole. The complex was characterized by elemental analysis, IR, and X-ray single crystal diffraction. The complex crystallized in the monoclinic crystal system and P21/m space group with a = 0.634790(10) nm, b = 0.963030(10) nm, c = 1.221770(10) nm, α = 90°, β = 95.9700(10)°, γ = 90°, V = 0.742844(15) nm3, Mr = 383.22, Dc = 1.713 g cm−3, Z = 2, F(0 0 0) = 398, μ = 1.206 mm−1, the final R = 0.0291, and wR = 0.0837 [I > 2σ(I )]. The interaction of the complex with deoxyribonucleic acid (DNA) was studied by electronic absorption spectra, fluorescence spectra, and viscosity measurements, which indicate that the complex binds to calf thymus DNA through a partially intercalative mode. The binding constant K b for the complex was 2.62 × 104 L mol−1. The antiproliferation activity test showed that the complex has high antiproliferative ability against human hepatoma cells SMMC7721 (with IC50 being 42.8 ± 0.9 µmol L−1) and human lung cancer cells A549 (with IC50 being 65.1 ± 3.2 µmol L−1). The inhibition rates of the complex are much higher than those of NCTD.
Acknowledgments
Financial support from Natural Science Foundation of Zhejiang Province (grant no. Y407301) is gratefully acknowledged.