| Thymol is the main monoterpene phenol present in the essential oils which is used in the food
industry as flavoring and preservative agent. In this study, the interaction of thymol with the concentration
range of 1 to 6 μM and bovine serum albumin (BSA) at fixed concentration of 1 μM
was investigated by fluorescence, UV‐vis, and molecular docking methods under physiological‐
like condition. Fluorescence experiments were performed at 5 different temperatures, and the
results showed that the fluorescence quenching of BSA by thymol was because of a static
quenching mechanism. The obtained binding parameters, K, were in the order of 104 M−1
, and
the binding number, n, was approximately equal to unity indicating that there is 1 binding site
for thymol on BSA. Calculated thermodynamic parameters for enthalpy (ΔH), entropy (ΔS), and
Gibb's free energy (ΔG) showed that the reaction was spontaneous and hydrophobic interactions
were the main forces in the binding of thymol to BSA. The results of UV‐vis spectroscopy and
Arrhenius' theory showed the complex formation in the interaction of thymol and BSA. Negligible
conformational changes in BSA by thymol were observed in fluorescence experiments, and the
same results were also obtained from UV‐vis studies. Results of molecular docking indicated that
the subdomain IA of BSA was the binding site for thymol. |