Synthesis of Amide Compounds of Ferulic Acid and Their Association with Bovine Serum Albumin

In this work, three new amide compounds of ferulic acid (FA) were synthesized. The fluorescence and ultraviolet spectroscopy were explored to study the interactions between three amide compounds of FA and bovine serum albumin (BSA) under imitated physiological conditions. The experimental results showed that the fluorescence quenching mechanism between BSA and three amide compounds of FA were mainly static quenching and nonradiation energy transfer at 25°C, 30°C, and 37°C. The Stern–Volmer quenching constants, the binding constants, and the number of binding sites and corresponding thermodynamic parameters ΔH, ΔG, and ΔS were calculated at different temperatures. From the thermodynamic parameters, we concluded that the action force was mainly a hydrophobic interaction. According to the Főrster theory of nonradiation energy transfer, the binding distances (r) between BSA and amide compounds are less than 7 nm. Furthermore, the effects of amide compounds on the conformation of BSA were analyzed using synchronous fluorescence spectroscopy.