BackgroundStaphylococcus aureus is a non-motile, gram positive, non-sporforming, facultative anaerobic microorganism. It is one of the important bacteria as a potential pathogen specifically for nosocomial infections. The sulfonamide derivative medicines are preferred to cure infection caused by S. aureus due to methicillin resistance.MethodsAntimicrobial activity of four sulfonamide derivatives have been investigated against 50 clinical isolates of S. aureus and tested by using MIC and disc diffusion methods. 50 clinical isolate which collected from specimens of patients who are given medical treatment in Ondokuz Mayis University Medical School Hospital. A control strain of S. aureus ATCC 29213 was also tested.ResultsThe strongest inhibition was observed in the cases of I [N-(2-hydroxy-4-nitro-phenyl)-4-methyl-benzensulfonamid], and II [N-(2-hydroxy-5-nitro-phenyl)-4-methyl-benzensulfonamid] against S. aureus. Compound I [N-(2-hydroxy-4-nitro-phenyl)-4-methyl-benzensulfonamid] showed higher effect on 21 S. aureus MRSAisolates than oxacillin antibiotic. Introducing an electron withdrawing on the ring increased the antimicrobial activity remarkably.ConclusionThis study may help to suggest an alternative possible leading compound for development of new antimicrobial agents against MRSA and MSSA resistant S. aureus. It was also shown here that that clinical isolates of 50 S. aureus have various resistance patterns against to four sulfonamide derivatives. It may also be emphasized here that in vitro antimicrobial susceptibility testing results for S. aureus need standardization with further studies and it should also have a correlation with in vivo therapeutic response experiments.

The exposure of human enamel and restorative materials to acidic drinks may accelerate the degradation process and so reduce the life time of filler materials at equivalent integral exposure times longer than three months. Clinical Relevance Erosive foods and drinks having acidic potential destroy not only tooth enamel but also restorative materials.

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The mechanism of acid-catalyzed hydrolysis of a series of p-substituted N,N′-diarylsulfamides was investigated in aqueous mineral acid solutions. Rate profiles, reaction activation parameters, catalytic order of strong acids, solvent isotope effects, and analysis of the kinetic data by the excess acidity method suggest a change in the mechanism from A2 to A1. While the hydrolysis proceeds with an A2 mechanism in low acidity regions, an A1 mechanism takes place in high acid concentrations.

The acid-catalysed hydrolyses of some N-(para-substituted pheny1)propane-I ,3-sultams have been studied in aqueous acidic solutions. The rate maxima observed are shown to be consistent with an A-2 mechanism in which extensive protonation of the substrate occurs. Values of pK,,+ for the sultams have been determined.Whilst the acid-catalysed hydrolysis of sulfonamides has been studied in some detail because of its relevance to the Hinsberg method for the separation of amines, very few studies of the hydrolyses of sultams (the corresponding cyclic sulfonamides) have been recorded.' Erman and Kretschmar reported that a number of five-membered N-alkyl sultams undergo hydrolysis in methanolic HCl or HBr or in glacial acetic acid.2 They suggested that acid catalysed cleavage of the ring proceeds via an A-1 mechanism by analogy to the mechanism proposed earlier for the acid-catalysed hydrolysis of sulfonamides3 although Klamann and his co-workers subsequently changed this view.4 In order to clarify the situation for the hydrolysis of sultams, we now report a detailed study of the protonation behaviour and kinetics of hydrolysis of a series of fivemembered N-arylpropane-1,3-sultams 1 in aqueous solutions of mineral acids.