Luminescent cyclometalated platinum(II) complexes with amino acid ligands for protein binding.

Pt(C/N)(phe)(1, C/N = 2-(2'-thienyl)pyridine, phe = phenylalanine) shows a high binding affinity (ca. 10(6) dm(3) mol(-1)) and selectivity towards human serum albumin (HSA) and such binding is accompanied by an enhancement of photoluminescence at 562 nm; both the protein binding affinity and cytotoxicities of [Pt(C/N)(phe)(1), Pt(C/N)(trp)(2, trp = tryptophan) and Pt(C/N)(gly)(3, gly = glycine)] are affected by the amino acid ligand with having an IC(50) of up to 1 microM against a number of carcinoma cell lines.