New Antioxidant Triphenol-Derived Hydrazide-Hydrazone Thiazole: Formation and Analysis of Inclusion Complex with β-CD Using Experimental and Computational Approaches.

A new water-soluble not-colored antioxidant (Z)-N'-(4-(3,4-dihydroxyphenyl)-3-ethylthiazol-2(3H)-ylidene)-4-hydroxybenzohydrazide hydrochloride (DHTH) was obtained and characterized. The interaction between DHTH and β-CD was studied by experimental thermodynamic methods such as isothermal titration calorimetry (ITC) and (1)H NMR spectroscopy and confirmed by in silico calculations. Thermodynamic data indicated that the inclusion process is driven by enthalpy, predominantly as a result of the guest-host hydrophobic interactions. (1)H NMR measurements were applied to study the interaction with β-CD by changing the studied compound concentration in the solution. UV-vis titration and in vitro antiradical assay were performed, to study the antioxidant activity of DHTH, free and included in β-CD. A molecular docking study added supplementary insight to the experimental analyses regarding the binding conformation of the new polyphenolic compound to β-CD.