The new salt of 2-amino-3-methylpyridine with dipicolinic acid and its metal complexes: Synthesis, characterization and antimicrobial activity studies

Abstract

A new proton transfer salt (3) synthesized from 2-amino-3-methyl pyridine with dipicolinic acid and its Fe(III) (4), Co(II) (5), Ni(II) and two Cu(II) (7 and 8) complexes were synthesized and characterized by NMR (1H and 13C), AAS, FT-IR, magnetic measurement, molar conductivity and UV. X–ray crystallography was performed to illuminate the structure of compounds 6 and 8. Additionally, metal salts (9–12), free compounds (1 and 2), simple metal complexes (13–20) of compounds 1 and 2 and synthesized compounds (3–8) have been assayed for their antimicrobial activities against Escherichia coli (ATCC 25,922) (Gram negative), Enterococcus faecalis (ATCC 29212) (Gram positive), Staphylococcus aureus (ATCC 29213) (Gram positive), Candida parapisilosis (ATCC 22019) (yeast), Candida albicans (ATCC 14053) (yeast) and Candida krusei (ATCC 6258) (yeast). Results of analyses were compared with Cefepime, Vancomycin and Levofloxacin (standard antibacterial agents) and Fluconazole (standard antifungal agents). Compounds with the best activity are 1, 3, 11, 16 and 17 (62.50) for E. Coli, 1, 11, 13 and 17 (31.25) for S. aureus, 11, 17 and 18 (31.25) for E. faecalis, 1, 3, 16 and 17 (31.25) for C. parapsilosis, 1 (15.60) for C. albicans and 1, 17, 18 and 20 (31.25) for C. krusei. Against all bacteria and yeasts, compound 17 had the highest activity (32.25) (except for C. albicans).