Synthesis and evaluation of potential antimicrobial agents

Antibiotic resistance is a global problem and the development of new drugs, among other approaches, should contribute to mitigating the consequences. All newly prepared compounds are based on the 4,6-dimethylpyrimidine-2-amine, in some syntheses its derivative sulfamethazine was used as a starting compound. The starting molecule was chosen based on the antimicrobial activity of 4,6-dimethylpyrimidine-2-amine derivatives. The aim of three one-step syntheses was to prepare sulfonamides from 4,6-dimethylpyrimidine-2-amine and corresponding sulfonyl chlorides. Other ten also one-step reactions led to the preparation of Schiff bases, which are mostly based on salicylaldehyde and benzaldehyde derivatives. Different methods were used, yields ranged from 13 % to 48 % for sulfonamides and from 13 % to 96 % for Schiff bases. All thirteen compounds were tested for antibacterial (against selected G+ and G- strains) and antifungal activity using the microdilution broth method. In general, the compounds were ineffective against G- bacteria and, on the other hand, showed the greatest activity (i.e., lowest minimum inhibitory concentrations, MIC) against fungi. Sulfonamides were ineffective. The lowest MICs for both fungi (3.9 µmol l-1) and bacteria (15.62 µmol l-1) were found for..