Synthesis and in vitro antibacterial activity of thymol and carvacrol derivatives.

Fourteen esters of thymol and carvacrol were synthesized and characterized on the basis of spectral data. The NMR data for some of these are being given for the first time. The antibacterial activity screening of thymol, carvacrol and their esters were carried out against four Gram-positive (Streptococcus mutans MTCC 890, Staphylococcus aureus MTCC 96, Bacillus subtilis MTCC 121, Staphylococcus epidermidis MTCC 435) and one Gram-negative (Escherichia coli MTCC 723) bacteria. The enhancement in activity was noticed in the thymyl ester derivatives 4a-c (against S. mutans, B. subtilis and S. epidermidis) in comparison to thymol, whereas the carvacrol derivatives were found to be much less active than carvacrol.