Synthesis, Characterization, and Antiproliferative Study of Some Complexes Containing Pyridine-N-oxide-2,6-dicarboxylic Acid

In this paper we report the synthesis and characterization of three new mixed-ligand cobalt and manganese complexes containing H2pydco = pyridine-N-oxide-2,6-dicarboxylic acid,  bipy = 2,2ꞌ˗bipyridine and phen = 1,10˗phenanthroline. The proposed formula and structures of these compounds have been determined by elemental analysis, infrared spectroscopy, Thermal gravimetric analysis (TGA-DTA), and melting point. A search of the Cambridge Structural Database (CSD version 5.38 updates May 2017) returned 2017 complexes with pyridine-2,6-dicarboxylic acid and 49 complexes with pyridine-N-oxide-2,6-dicarboxylic acid ligands. It can be emphasized that the lack of similar and suitable complexes containing N˗oxidized H2pydco ligand in the articles of any comparison in this family has been confronted. In addition, the cytotoxicity of these three complexes was used to evaluate their antiproliferative activity on HeLa cells (human ovarian carcinoma), MCF-7 (human breast cancer), HT-29 (human colon cancer), K-562 (human myeloid cell cancer), Neuro-2a (mouse murine neuroblastoma), and L929 (rat cell fibroblast cell line, normal cell) were evaluated by MTT assay and compared with cisplatin as a reference. The results showed more cytotoxicity for complexes 2 and 3 against MCF-7 and HT-29 cell lines compared to cisplatin.