Experimental and theoretical studies on methanesulfonic acid 1-methylhydrazide: Antimicrobial activities of its sulfonyl hydrazone derivatives Neslihan Özbek a , Saliha Alyar b , Nurcan Karacan b, * a Department of Primary Education, Faculty of Education, Ahi Evran University, 40100 Kırs ßehir, Turkey b Department of Chemistry, Science and Art Faculty, Gazi University, 06500 Ankara, Turkey article info Article history: Received 31 July 2009 Received in revised form 28 August 2009 Accepted 1 September 2009 Available online 6 September 2009 Keywords: Antimicrobial activity Sulfonyl hydrazone Sulfonyl hydrazide NMR spectra DFT abstract Methanesulfonic acid 1-methylhydrazide (msmh) and its sulfonyl hydrazone derivatives, salicylaldehyde- N-methylmethanesulfonylhydrazone (salmsmh) and 2-hydroxy-1-naphthaldehyde-N-methylmethane- sulfonylhydrazone (nafmsmh) were synthesized and characterized by using FT-IR, 1 H NMR, 13 C NMR, LC– MS and elemental analysis. Conformation analysis of msmh based on DFT/B3LYP/6-311G(d) method was performed. 1 H and 13 C shielding tensors of msmh for the most stable conformer were calculated with GIAO/DFT/B3LYP/6-311++G(2d, 2p) methods in vacuo and various solvents such as DMSO, THF, acetoni- trile, methanol and aqueous solution. The harmonic vibrational wavenumbers for the most stable con- former were calculated using at B3LYP/6-311G(d) level. Antimicrobial activity of the compounds was also screened against Gram-positive bacteria ( Staphylococcus aureus ATCC 25923, Bacillus cereus RSKK 863) and Gram-negative bacteria (Escherichia coli ATCC 11230, Salmonella enterititis ATCC 40376, Pseudomo- nos aeruginosa ATCC 28753) by both disc diffusion and micro dilution methods. Ó 2009 Elsevier B.V. All rights reserved. 1. Introduction Sulfonamides and sulfonyl hydrazones have been shown to be active in several pharmacological tests, demonstrating antibacte- rial, antitumor, diuretic, antiviral, antinociceptive activity, specific enzyme inhibition such as carbonic anhydrase, c-secretase HIV- protease, metalloproteinase, and hormone regulation among oth- ers [1,2]. Furthermore, sulfonyl-hydrazine carrying ion-exchange beads were used as an ion-exchange support for adsorption of human serum albumin (HSA) from aqueous solution [3]. Sulfonyl hydra- zides grafted onto the nanoparticles are also used as polymerizable foaming agent [4]. Despite to its importance in medicinal and polymeric fields, only a small amount of papers on calculations of sulfonyl hydra- zides and their derivatives have been reported so far [5–10]. In our previous study, experimental and theoretical study of methanesulfonic acid hydrazide was reported [11]. Recently, we have published some calculations and experimental data of some sulfonyl hydrazone [12,13] and their metal carbonyl complexes [14,15]. As part of our ongoing studies, the aims of the present work is to study the conformational behavior of msmh, as well as its NMR spectra from experimental and theoretical viewpoints as a contri- bution to the understanding of the rational drug design of sulfonyl hydrazide. Antibacterial activities of msmh and its sulfonyl hydra- zones obtained by the condensation of salicylaldehyde and naph- thaldehyde were also evaluated against Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Bacillus cereus RSKK 863) and Gram-negative bacteria (Escherichia coli ATCC 11230, Salmonella enterititis ATCC 40376, Pseudomonos aeruginosa ATCC 28753) by both disc diffusion and micro dilution methods. 2. Experimental 2.1. Physical measurements The elemental analyses (C, H, N and S) were performed on a LES- CO-CHSNO-9320 type elemental analyzer. The 13 C NMR and 1 H NMR spectra were recorded on a Bruker WM-400 spectrometer at 400 MHz and at ambient temperature using d 6 -DMSO solutions with TMS as internal reference. IR spectrum was recorded in the range of 4000–400 cm À1 as KBr disc with Mattson 1000 FT spec- trometer. LC/MS-EI was recorded on AGILENT 1100. TLC was con- ducted on 0.25 mm silica gel plates (60F254, Merck). Chemicals were obtained from Aldrich and used without further purification. 2.2. Synthesis of msmh Methanesulfonyl chloride (0.04 mol) in tetrahydrofuran (25 mL) was added methylhydrazine (0.08 mol) in dropwise while 0022-2860/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.molstruc.2009.09.002 * Corresponding author. Tel.: +90 3122021117; fax: +90 3122122279. E-mail address: nkaracan@gazi.edu.tr (N. Karacan). Journal of Molecular Structure 938 (2009) 48–53 Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: www.elsevier.com/locate/molstruc