Synthesis, Configuration, and Antimicrobial Properties of Novel Substituted and Cyclized ‘2′,3″-Thiazachalcones’

Abstract

Nine new thiazachalcone-based drugs, compounds 1-9, were prepared and fully characterized. The configurations of the photochemical-dimerization products 7-9 were rationalized by semi-empirical calculations. Both the experimental data and the theoretical calculations showed that the ?-truxinic acid type dimer is the most stable isomer of all. All compounds were tested for their antibacterial and antifungal activities. The N-alkylated congeners 4-6 showed strong antimicrobial activities against various bacteria and a yeast-like fungus. The MIC and MBC values were as low as 0.1 ?g/ml. All the compounds were active against the Gram-positive bacterium Staphylococcus aureus. © 2007 Verlag Helvetica Chimica Acta AG.