Tricarbonylrhenium(I) complexes of phosphine-derivatized amines, amino acids and a model peptide: Structures, solution behavior and cytotoxicity

Abstract

Modified Mannich reactions of amines, amino acids and a model peptide with Ph2PH and CH2O gave bis(disphenylphosphinomethyl) amines(Ph2PCH2)2NR [R = Ph (1), CH2CH2OH(2), CH2COOCH2Ph (3), CH2CONHCH2COOCH2Ph (4). CH2COOH (5)] and [ReBr(CO)3(Ph2PCH2)2NCH 2]2 (12). All new complexes have been characterized by NMR and IR spectroscopy and for 7, 9 and 10, single-crystal X-ray diffraction analyses. Electrospray mass spectrometric studies show that the rhenium-phosphine chelates are very stable especially in neutral methanolic solution. Hydrolysis of the ester and amide linkages slowly occur in acidic and basic solutions over several weeks; displacement of the bromide ligand also occurs in basic medium. Cytotoxicity testing of 7-10 and 12 showed that all the complexes are active againts specific tumor cell lines, especially MCF-7 breast cancer and HeLa-S3 suspended eturine carcinoma. © 2002 Elsevier Science B.V. All rights reserved.