Voltammetric study of the interaction between oxacillin sodium and cysteine in the presence and absence of Mn(II)ions in neutral buffer solution

In this study, the voltammetric behaviour of the interaction of oxacillin sodium (OXA) and OXA-cysteine (RSH) was studied by square-wave voltammetry, cyclic voltammetry in Britton-Robinson (B-R) buffer (pH 7.0). OXA gave two peaks at -0.248 and -1.224 V. For the interaction, the peak of mercurous cysteine thiolate (Hg2(SR)2) was selected. It was found that the peak currents corresponding to Hg2(SR)2 significantly decreased, while the peak potential shifted to more positive potentials upon the addition of OXA. The observed phenomena are due to the interaction of OXA with RSH on the surface of the mercury electrode. When OXA was added to the electrochemical cell along with Mn(II), new peaks at -0.146 and -0.608 V were observed. These peaks were due to the catalytic activity of OXA on the reduction of Mn(II) and could be attributed to the formation of Mn(II) complexes with different metal/ligand ratios. On the other hand, in the presence of RSH, the peak at -0.608 V vanished and a reduction peak was observed at -0.662 V. The catalytic reduction peak potential of Mn(II) at -0.662 V indicated that RSH slightly prevented the catalysis process of OXA due to their mutual interaction. . U radu je ispitivano voltametrijsko ponasanje natrijum-oksacilina (OXA) i interakcije OXA i cisteina (RSH) u Briton-Robinsonovom (Britton-Robinson, B-R) puferu pH 7.0 koriscenjem voltametrije sa pravougaonim talasom i ciklicne voltametrije. OXA je pokazala dva voltametrijska pika: na -0.248 i -1.224 V. Za ispitivanje interakcija izabran je pik cisteintiolata zive (Hg2(SR)2). Zapazeno je da strujni pikovi koji poticu od Hg2(SR)2 nakon dodatka OXA znacajno opadaju i da se potencijal pika pomera ka pozitivnijim vrednostima. To potice od interakcija OXA sa RSH na povrsini zivine elektrode. Kada se u elektrohemijsku celiju dodaju i OXA i Mn(II) joni, pojavljuju se novi pikovi na -0.146 i -0.608 V. Oni poticu od kataliticke aktivnosti OXA za redukciju Mn(II) jona i mogu se pripisati formiranju Mn(II) kompleksa sa razlicitim odnosima metalnog jona i liganda. S druge strane, u prisustvu RSH pik na -0.608 V nestaje, a zapaza se redukcioni pik na -0.662 V. Potencijal pika kataliticke redukcije Mn(II) na -0.662 V ukazuje da RSH u izvesnoj meri umanjuje kataliticku aktivnost usled njihove medjusobne interakcije. .