Synthesis, characterization and in vitro antibacterial analysis of carvacrol based-hybrid analogues

he focus of this research was to synthesize and characterize carvacrol hybrid analogues. Twenty-one (21) carvacrol analogues were synthesized by reacting carvacrol with (1. 4- aminosalicylic acid, 2. ferrocene keto-butanoic acid, 3. Ferrocene butanoic acid, 4. succinic anhydride, 5. folic acid, 6. cinnamic acid, 7. leucovorin, 8. oleanolic acid, 9. artesunate, 10. cholesterol, 11. cholesterol succinate, 12. curcumin, 13. curcumin succinate, 14. zidovudine, 15. Zidovudine succinate, 16. 8-hydroxyquinoline, 17. 8-hydroxyquinoline succinate, 18. 2- (7-chloroquinolin-4-ylamino)ethyl 5-isopropyl-2-methylphenyl, 19. 2-(7-chloroquinolin-4- ylamino)ethyl 5-isopropyl-2-methylphenyl succinate, 20. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl, 21. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl succinate). The carvacrol analogues were characterized using FTIR, UHPLC-HRMS, 1H- and 13C-NMR spectroscopy. The antibacterial analysis was performed to evaluate the carvacrol analogues against bacterial strains. FTIR spectra of carvacrol analogues were found to exhibit peaks of C-O stretch and Ar-C in a range of 1014-1280 cm-1 and a range of 1414-1697 cm-1 which confirm the successful formation of esters. The proposed structures of carvacrol analogues were confirmed by the 1H- and 13C-NMR. The selected 1H-NMR signal for aromatic protons ranged at 6.00-8.95 ppm/δ. The selected 13C-NMR signal for ester carbon and aromatic carbons ranged at 160.0-175.0 ppm/δ and at 110.00-154.00 ppm/δ. The structures were also confirmed by UHPLC-HRMS. Carvacrol analogues exhibited the highest inhibitory effect against Gram-positive and Gram-negative tested bacterial strains