New Sulfonamides Derived from Carvacrol: Compounds with High Antibacterial Activity against Resistant Staphylococcus aureus Strains

Abstract

Nine new sulfonamides derived from carvacrol were prepared through a reaction between 4-hydroxy-2-isopropyl-5-methyl benzene sulfonyl chloride with various amines in excellent yields (76% -92%). The sulfonamides were characterized using spectrometric and spectroscopic me-thods. Among these compounds, three derivatives showed excellent results in antibacterial activi-ty against resistant S. aureus strains, with MIC values ranging from 3.9 to 62.50 ppm. The sulfona-mide derivative of 4-methylaniline (SULF-1) had the best performance for all tested strains of bacteria (MIC = 3.9 to 15.62 ppm). Furthermore, the sulfonamide derivative of 4-fluoro aniline (SULF-3), which also presented promising results, was found to have a synergistic effect when combined with tetracycline and partial synergistic effect when combined with ampicillin, exhibit-ing an FIC index between 0.50 and 0.75. The sulfonamide derivative of 4-methylaniline had a syn-ergistic effect in combination with erythromycin exhibiting an FIC index of 0.37. Carvacrol in asso-ciation with the antibiotics tested did not have a synergistic effect.