Voltammetric determination of sodium 5-(7-amino-3-cyanopyrazolo[1,5-a]pyrimidin-6-yl)tetrazol-2-ide as a promising antitumor molecule

The electrochemical behavior of sodium 5-(7-amino-3-cyanopyrazolo[1,5-a]pyrimidin-6-yl)tetrazol-2-ide (compound 1) as a promising inhibitor of casein ki-nase 2, a novel target in anticancer therapy, was investigated for the first time. Compound 1 undergoes irreversible electrooxidation on a glassy carbon electrode (GCE) in aqueous media, producing two poorly resolved peaks caused by amino group oxidation. The first oxidation step, involving a two-electron transfer, is diffu-sion-controlled and complicated by a preceding chemical reaction. The peak current of the first oxidation step of the amino group of compound 1 in the potential range 0.0–1.25 V was used as the response. The influence of voltammetric mode, electro-lyte pH, potential scan rate, accumulation time and potential on the oxidation peak current of compound 1 was studied. A method of compound 1 quantification by di-rect differential pulse voltammetry was developed. The peak current obtained in 0.1 M KCl was linearly related to the compound 1 concentration in the range of 0–160 mg/L with the determination coefficient of 0.999. The method provided a detection limit of 1.9 mg/L and recovery close to 100%.