Physicochemical and electrochemical characteristics of pyrazine-2-thiocarboxamide and its interaction ability against biomolecules

The pyrazine-2-thiocarboxamide (PTCA) as a pyrazine derivative with proven antifungal properties has for the first time been the subject of extensive research to evaluate its physicochemistry and ability to interact with biomolecules. The complete physicochemical and electrochemical profile of the studied compound together with its ionic species assignment were established as well as reported. The electrochemical characteristic of PTCA was examined in both: aqueous and aprotic solvent using the cyclic voltammetry technique. All the experimental results obtained were supported and compared with the DFT calculations. Furthermore, the pH effect on the redox processes and PTCA spectroscopic properties were also studied. The pKa values of the compound were determined using combined potentiometric and spectrophotometric/voltammetric (micro)titration methods. The detailed analyses of the PTCA's affinity to Calf thymus DNA and to Bovine Serum Albumin considered in scientific assay as potential cellular targets were the most important parts of the presented study. Indeed, a possible intercalation interaction mode was demonstrated for PTCA-DNA system studied by both spectrophotometric and electrochemical data which has never been reported before. Interestingly, values received by using the broad spectrum of techniques with different, individual measurable parameters have been showed a good agreement compared.