Synthesis, characterization, photoluminescence and electrochemical properties of Pt(II) and Ag(I) complexes of tetradentate aminomethylphosphine ligands and antiproliferative activities on HT-29 human colon cancer

Novel N-1,N-1,N-4,N-4-tetrakis((diphenylphosphino)methyl)benzene-1,4-diamine (L1), N-1,N-1,N-5,N-5-tetrakis((diphenylphosphino)methyl)naphthalene-1,5-diamine (L2) and 4,4-methylenebis(N,N-bis((diphenylphosphino)methyl)aniline) (L3) ligands and their Pt(II) and Ag(I) complexes have been synthesized under nitrogen atmosphere using the Schlenk technique. The ligands and the complexes were characterized using H-1 NMR, P-31 NMR and Fourier transform infrared spectroscopies, thermogravimetric/differential thermal analysis, elemental analysis (C, H, N), inductively coupled plasma optical emission spectrometry (metal content), cyclic voltammetry and photoluminescence. All the complexes were investigated as anticancer agents on HT-29 human colon cancer cell line. HT-29 cells were treated with various concentrations (10, 25, 50, 100, 250 M) of Pt(II) and Ag(I) tetrakisditertiaryaminomethylphosphine complexes. Cisplatin was tested at the same concentrations in order to compare the antiproliferative activities of the synthesized Pt(II) and Ag(I) complexes. Pt(II) complexes of L1 and L3 and Ag(I) complexes of L1, L2 and L3 showed a similar inhibition effect of cancer cell proliferation when compared to cisplatin up to 50 M; at 100 M and higher concentrations, L1-Pt(II) and L3-Ag(I) complexes showed a much greater effect than cisplatin. Copyright (c) 2016 John Wiley & Sons, Ltd.