Modulating anti-inflammatory and anticancer properties by designing a family of metal-complexes based on 5-nitropicolinic acid.

A new family of six complexes based on 5-nitropicolinic acid (5-npic) and transition metals has been obtained: [M(5-npic)] (M = Mn (1) and Cd (2)), [Cu(5-npic)] (3), and [M(5-npic)(HO)] (M = Co (4), Ni (5), and Zn (6)), which display 1D, 2D, and mononuclear structures, respectively, thanks to different coordination modes of 5-npic. After their physicochemical characterization by single-crystal X-ray diffraction (SCXRD), elemental analyses (EA), and spectroscopic techniques, quantum chemical calculations using Time-Dependent Density Functional Theory (TD-DFT) were performed to further study the luminescence properties of compounds 2 and 6. The potential anticancer activity of all complexes was tested against three tumor cell lines, B16-F10, HT29, and HepG2, which are models widely used for studying melanoma, colon cancer, and liver cancer, respectively. The best results were found for compounds 2 and 4 against B16-F10 (IC = 26.94 and 45.10 μg mL, respectively). In addition, anti-inflammatory studies using RAW 264.7 cells exhibited promising activity for 2, 3, and 6 (IC = 5.38, 24.10, and 17.63 μg mL, respectively). This multidisciplinary study points to complex 2, based on Cd, as a promising anticancer and anti-inflammatory material.