Green synthesis, X-ray crystal structure, evaluation as in vitro cytotoxic and antibacterial agents of a new Zn(II) complex containing dipicolinic acid

A zinc(II) complex formulated as (4-apyH)2[Zn(pydc)(pydcH)]2.(pydcH2)2.10H2O was prepared through a one-pot reaction of pyridine-2,6- dicarboxylic acid, 4-aminopyridine, and zinc chloride anhydrous metal salt. In all the steps, only distilled water was used as the solvent. The compound was fully characterized by single-crystal X-ray diffraction and disordered octahedral geometry was recognized for it. The cytotoxicity of the complex and its ligands was evaluated by MTT method against A375, LN229, DLD1, HT29, and HFF cell lines. The strongest anti-proliferative effect of the complex was exhibited toward HT29 (IC50=10 µM, Viability inhibition =78.23%) cells. The apoptosis was proposed as the main pathway for the death of the cells according to the product of ROS high value and reduction of MMP. The antibacterial effect of compounds was studied against two Gram-positive bacteria namely Staphylococcus aureus, and Staphylococcus epidermidis, and also three Gram-negative bacteria namely Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris. The established antibacterial tests were including the broth microdilution method and the agar well diffusion method. S. aureus (MIC=16 µg/mL, IZD=30 mm) and S. epidermidis (MIC=32 µg/mL, IZD=22 mm) were considered as the most susceptible bacteria following treatment of the complex.