Synthesis of several sulfonamide derivatives and their some transition metal complexes, evaluation of antimicrobial activities

In this study, benzenesulfonicacid-1-methylhydrazide (bsmh), N-(3-amino-2-hydroxypropylbenzenesulfonamide) (bsdiap) and N-(2-hydroxyethylbenzene sulfonamide (bsea) were synthesized by the reaction of benzenesulfonyl chloride with various amines, namely methyl hydrazide, 1,3-diamino-2-hydroxypropane and ethanolamine, respectively. Then, four new sulfonyl hydrazones of bsmh, i.e. salicylaldehyde benzenesulfonylhydrazone (Hsalbsmh), 2-hydroxy-1-naphtaldehydebenzenesulfonylhydrazone(Hnafbsmh), 2-hydroxy-1-acetophenon benzenesulfonylhydrazone (Hafbsmh) and thiophene-2-carbaldehyde benzenesulfonyl hydrazone (t2kbsmh) were prepared. Elemental analysis, LC-MS, 1H-NMR, 13C-NMR, FTIR data are made use of for characterization and DFT/B3LYP/GIAO computational predictions were compared with the experimental findings.Complexes of tetra-coordinated M(salbsmh)2 and M(nafbsmh)2, M = Co(II), Ni(II), Pd(II), Pt(II) and Cu(II) were synthesized and their structures were elucidated by LC-MS, FTIR, conductivity and magnetic susceptibility techniques.Antimicrobial activity of sulfonamide derivatives and coordination complexes were evaluated in vitro against Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 11778, Pseudomonas fluorescens ATCC 49838, Klebsiella pneumonia ATCC 13883, Enterococcus faecalis ATCC 29212, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus epidermidis ATCC 12228, Enterobacter aerogenes ATCC 13048 and Candida albicans ATCC 90028 by paper disc diffusion and microdilution methods. The compounds were found to have abroad-range activity against microorganisms. Generally, sulfonamides show activity against Gram-negative bacteria, however sulfonyl hydrazones have activity against Gram positive bacteria and C. albicans yeast. Bsmh shows higher antibacterial and lower antifungal activity than other compounds. t2kbsmh possessing thiophene group was more active than Hnafbsmh having naphtaldehyde group. In addition, ML2 ( M= Pt(II), Pd(II) and L = nafbsmh and salbsmh) complexes show good antibacterial and antifungal activity against all microorganisms. However, Ni(nafbsmh)2 and Ni(salbsmh)2 complexes show only antimicrobial activity against P. fluorescens and E. coli bakteria.Key Words:Sulfonamides, sulfonyl hydrazides, sulfonylhydrazone, metal complexes, DFT, GIAO, antimicrobial activity, MIC