Synthesis of (E)-Ethyl-4-(2-(furan-2-ylmethylene)hydrazinyl)benzoate, crystal structure, and studies of its interactions with human serum albumin by spectroscopic fluorescence and molecular docking methods

A novel hydrazone, (E)-Ethyl-4-(2-(furan-2-ylmethylene)hydrazinyl)benzoate (EFHB), has been synthesized and characterized by FT-IR, NMR and Mass spectroscopy, and X-ray diffraction; compound crystallized as translucent light yellow thin plates. EFHB was studied for their binding to human serum albumin (HSA) using the fluorescence quench titration method. Molecular docking was also performed to get a more detailed insight into their interaction with HSA at the binding site. Addition of this hydrazone to HSA produced significant fluorescence quenching and splitting of emission spectra of HSA through static quenching mechanism with binding constants of about 10⁴ M⁻¹ at 292.15, 298.15, 304.15 and 310.15 K. According to the synchronous fluorescence, tryptophan and tyrosine residues of the protein are most perturbed by the binding process. Thermodynamic parameters ΔG, ΔH, and ΔS were got and the main sort of acting force between EFHB and HSA was studied. Results of molecular docking have shown that EFHB binds to subdomain IIA of HSA mainly by hydrophobic interaction, energy binding are in good agreement with those obtained by fluorescence study (ΔG_the = −7.32 ± 0.09 kcal mol⁻¹ and ΔG_exp = −6.76 ± 0.03 kcal mol⁻¹).