Synthesis, characterization, anti-microbial activity studies of 2-methoxy-5-sulfamoylbenzoic acid and 2-aminopyridine derivatives salts and their Cu(II) complexes

Two new salts (4 and 5) obtained between 2-methoxy-5-sulfamoylbenzoic acid (1) and 2-aminopyridine (2) or 2-amino-4-methylpyridine (3), and their Cu(II) complexes (6 and 7) have been obtained. The structures of the salts (4 and 5) were suggested by elemental analysis, NMR, FT-IR and UV-Vis, while the structures of Cu(II) complexes (6 and 7) were suggested by elemental analysis, AAS, UV-Vis and magnetic susceptibility techniques. While the acid:base ratio was 2:1 for 4 and 1:1 for 5 salts, the metal:acid:base ratio was 1:2:2 for 6 and 7. According to the results of spectroscopic analysis, the structures of 6 and 7 compounds were proposed as octahedral. Additionally, antimicrobial activities of all compounds were studied against Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (NRRL B-767), Bacillus subtilis, Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC25922) and Listeria monocytogenes (ATCC 7644) bacteria and Candida albicans (F89) yeast. The results were comparisoned with the antibiotics (Fluconazole, Vancomycin, Cefepime and Levofloxacin). All compounds showed activity against bacteria and yeasts. Compounds Cu(OAc)2.2H2O (31.25 μg/mL) for C. Albicans, 1 and 7 (31.25 μg/mL) for L. monocytogens, all compounds (except 6) (7.60 μg/mL) for B. subtilis, 2 (31.25 μg/mL) for E. Coli, 7 (15.60 μg/mL) for S. aureus, 7 (31.25 μg/mL) for E. Faecalis, and 3 (15.60 μg/mL) for P. aeruginoa have the best activity.