Synthesis and spectroscopic studies of potential anticancer [platinum(II)(2,2' -bipyridine)(amino acid)] n+ (n = 1 or 2) complexes

Abstract

Six new platinum complexes of the formula [Pt(2,2'-bipyndine)(amino acid)] n+, where n = 1 to 2 and amino acid is an anion of L-histidine, L-lysine, L-asparagine, L-phenylalanine, L-tryptophan, or L-tyrosme, have been prepared by interaction of [Pt(2,2 '-bipyndine)Cl 2] and an appropriate ammo acid (sodium salt) in water or water-methanol mixture. They have been characterized by chemical analyses and spectral methods such as ultraviolet-visible, infrared, and 1H NMR spectroscopy. The 1H NMR studies of these complexes ascertain the modes of binding of ammo acids to platinum. The histidine binds to platinum through the nitrogen of a -NH; group and another nitrogen of heterocyclic ring. All other ammo acids bind to platinum through nitrogen of a -NH 2 group and oxygen of a -COO − group. The mode of binding of some ammo acids to platinum in these complexes has been further confirmed by infrared spectroscopy, and the formulations of these complexes have been supported by conductivity measurements. These six amino acid complexes and also other complexes of glycine, alanine, leucine, serine, cysteme, methionine, and glutamine have shown growth inhibition against P-388 lymphocytic leukemic cells.