Ternary copper(II) complexes with hippurate derivatives and 1,10-phenanthroline: Synthesis and biological activity

Several new Cu–hippurate derivative–phenanthroline ternary complexes have been prepared. The X-ray structure of one of them, [Cu(hip)(phen)2]+·(hip−) (2) (where hip is hippurate and phen is 1,10-phenanthroline) has been solved. The structure of this new compound shows important differences (3D-pattern) to other similar related complexes (2D-pattern). A study of the biological activity of [Cu(hip)(phen)2]+·(hip−)·2H2O (2), [Cu(BGG)(phen)2]+·(BGG−)·6H2O (3), [Cu(BIGG)2(phen)](H2O) (4) and [Cu(I-hip)(bpy)2]+·(I-hip−)·3.5H2O (5) (where I-hip is ortho-iodohippurate, BGG corresponds to benzoylglycilglycine, and BIGG is ortho-iodobenzoylglycilglycine) is included and compared with the anti-proliferative activity of [Cu(I-hip)(phen)2]+·(I-hip−)·7H2O (1) previously described, resulting in a greater cytotoxic activity of the compounds with 1,10-phenanthroline instead of those with 2,2′-bipyridyl, in the same way that removing iodine substitution or lengthening the peptidic chain diminishes the activity of compounds compared with 1. The presence of an ortho-iodine group and the direct bond between Ar–CO and glycine moieties yield to the best results.