Deciphering the binding mechanisms of eugenol and 2-methylpyrazine with human serum albumin using technical approach

Eugenol (EGL) and 2-methylpyrazine (2-MTP) are common food additives that are used as flavors in a variety of foods. To study the effect of food additives on human serum albumin (HSA), it is necessary to deeply study the interaction of EGL and 2-MTP with HSA. Fluorescence, UV–vis absorption, circular dichroism (CD) and computational techniques showed EGL and 2-MTP bind statically to HSA, inducing conformational changes of HSA. We calculated the quenching constants (k sv ), binding constants (k q ), binding distances (r) and thermodynamic constants (ΔH 0 , ΔS 0 , ΔG 0 ) at four different temperatures. Based on thermodynamic analysis and molecular dynamics (MD) simulations, the main forces of 2-MTP-HSA and EGL-HSA systems are hydrophobic interaction and π-π accumulation, respectively. In addition, the interaction alters the physiological activity of HSA, esterase activity and free radical scavenging ability. This study provides valuable insights into the molecular interactions of food additive compounds EGL and 2-MTP with HSA, the findings provide theoretical reference for the development of new food additives and drugs in the future.