Cyclic Voltammetric Studies of Nitroimidazoles in Aqueous Solution with Additions of Cysteine
Because of the high reactivity of the nitroso and hydroxylamine imidazoles, it is not generally possible to prepare and isolate them to study their reactivity directly. However they can be studied indirectly using cyclic voltammetry since upon reduction of the nitro group in aqueous solution new peaks due to the oxidation of the hydroxylamine and reduction of the nitroso can be seen. By varying the scan rate, information on the stability of these species in aqueous solution can be obtained. Further information on the activity of the nitroso and hydroxylamine forms can be obtained by adding equivalents of cysteine to the cell in order to monitor the rate of reaction between cysteine and the nitroso and hydroxylamine forms of different imidazoles.
This paper will describe the cyclic voltammetry of 1-methyl-5-nitroimidazole and 1-methyl-2-nitroimidazole in aqueous solution in greater detail. Rough estimates of the lifetimes of nitroso and hydroxylamine derivatives in water will be determined using the current vs. time data at different scan rates. If possible, better estimates of the lifetimes and the rates of reaction with cysteine will be obtained by simulation of the voltammograms.