A novel bidentate ligand containing oxime, hydrazone and indole moieties and its BF₂⁺ bridged transition metal complexes and their efficiency against prostate and breast cancer cells

In this study, a novel bidentate ligand containing oxime, hydrazone, and indole moieties and its BF2+-bridged transition metal complexes [Ni(II), Cu(II), and Co(II)] were synthesized and their cytotoxic activities against prostate and breast cancer cells were investigated. The vic-dioxime ligand bearing indole-hydrazone side groups was synthesized by reacting antiglyoximehydrazine (GH(2)) with 3-methoxy indole. The ligand forms mononuclear complexes with a metal-to-ligand ratio of 1:2 with M = Co(II)(H2O)(2), Ni(II), and Cu(II). These metal complexes were then reacted with BF3(C2H5)(2)O to obtain BF2+-bridged transition metal complexes. The Co(II) complex of the ligand is proposed to be octahedral with water molecules as axial ligands, whereas the Ni(II) and Cu(II) complexes are proposed to be square planar. Spectral studies showed that the ligand bonded to the metal ion in a neutral bidentate fashion through the azomethine nitrogen atom and the imine oxime group. Structural assignments are supported by a combination of H-1 nuclear magnetic resonance (NMR), C-13 NMR, Fourier-transform infrared, LC/MS, elemental analyses, and magnetic susceptibility testing. For determining the cytotoxic effects of the novel anticancer products, cancer cells were cultured. The antiproliferative effects were determined using the MCF-7 breast cancer and PC-3 prostate cancer cell lines. The antiproliferative effects of the products were analyzed and their apoptotic or necrotic effects were determined with the Hoechst/propidium iodide double staining method in both cancer cell lines. Paclitaxel was used as the positive control (1 mu m). The results indicated that the newly synthesized compounds are effective on both cell lines between concentrations of 5 and 40 mu m and show their effects by apoptotic mechanisms. Besides, these products were found to be more effective on the MCF-7 cell line. The cytotoxic efficiency of the newly synthesized products was more than that of paclitaxel (depending on concentration), which is a chemotherapeutic agent used in cancer therapy.