Study of the Interactions of Bovine Serum Albumin with the New Anti-Inflammatory Agent 4-(1,3-Dioxo-1,3-dihydro-2H-isoindol-2-yl)-N'-[(4-ethoxy-phenyl)methylidene]benzohydrazide Using a Multi-Spectroscopic Approach and Molecular Docking.

The lipophilic derivative of thalidomide (4-(1,3-dioxo-1,3-dihydro-2-isoindol-2-yl)--[(4-ethoxyphenyl)methylidene]benzohydrazide, ) was synthesized to enhance its characteristics and efficacy. Earlier studies have proved the immunomodulatory and anti-inflammatory effects of . In this study the interaction between bovine serum albumin (BSA) and was studied using a multi-spectroscopic approach which included UV spectrophotometry, spectrofluorimetry and three dimensional spectrofluorometric and molecular docking studies. Static quenching was involved in quenching the fluorescence of BSA by , because a complex formation occurred between the and BSA. The binding constant decreased with higher temperature and was in the range of 2.5 × 10⁵-4.8 × 10³ L mol suggesting an unstable complex at higher temperatures. A single binding site was observed and the the site probe experiments showed site II (sub-domain IIIA) of BSA as the binding site for . The negative values of ∆G⁰, ∆H⁰ and ∆S⁰ at (298/303/308 K) indicated spontaneous binding between and BSA as well as the interaction was enthalpy driven and van der Waals forces and hydrogen bonding were involved in the interaction. The docking results and the results from the experimental studies are complimentary to each other and confirm that binds at site II (sub-domain IIIA) of BSA.