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Abstract
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The electrochemical synthesis of arylsulfonyl-4,40-biphenol (ASB) and bis-phenylsulfonyl-4,40-biphenol (BASB) derivatives was carried out via the electrochemical oxidation of 4,40-biphenol in the presence of arylsulfinic acids as nucleophiles using a carbon anode. Our data demonstrate that the arylsulfinic acids participate in Michael type addition reaction with the electrogenerated 4,40-diphenoquinone, converts it to the arylsulfonyl-4,40-biphenol or bis-phenylsulfonyl-4,40-biphenol derivatives depends on electrode potential. The arylsulfonyl-4,40-biphenols were evaluated for their in vitro antibacterial activity against Escherichia coli (E. coli) ATCC 35218 (Gram-negative) and Staphylococcus aureus (S. aureus) ATCC 6538 (Gram-positive). It was found that the tested compounds were more active against gram-positive than gram-negative bacteria. It was also found that the antimicrobial activity of ASB derivatives to vary in the order ASB-CH3 > ASB-Cl > ASB-H. Furthermore, based on the EC mechanism, the observed homogeneous rate constants (kobs) of the reaction of 4,40-diphenoquinone with arylsulfinic acids were estimated by comparing the experimental cyclic voltammograms with the digital simulated results in various pH values.
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