Antimicrobial Evaluation of Some Arylsulfanylpyrazinecarboxylic Acid Derivatives

The radical-ionic coupling of chloropyrazine-2-carboxylic acid derivatives with methoxybenzenethiols, carried out in the presence of a heterogeneous copper catalyst, provided the series of 6- or 5- or 3-(4-methoxyphenyl)sulfanylpyrazine- 2-carboxylic acid derivatives as well as 6- or 5- or 3-(3-methoxyphenyl)sulfanylpyrazine-2-carboxylic acid derivatives. The prepared compounds were evaluated as potential antifungal agents and new antituberculotics. Their preliminary in vitro evaluation of antimycobacterial activity according to the international program with the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF) is presented. Several compounds showed an interesting activity in the preliminary screening with a percentage growth inhibition of the virulent Mycobacterium tuberculosis H37Rv between 50 to 100% at the concentration 6.25 μg/mL. Structure-activity relationships among the chemical structure, the physical properties and the biological activities of the evaluated compounds are discussed in the article.