Determination of stoichiometric coefficients and apparent formation constants for beta-cyclodextrin complexes of trans-resveratrol using reversed-phase liquid chromatography.
J Chromatogr A 2006;
1135:158-65. [PMID:
17083948 DOI:
10.1016/j.chroma.2006.09.013]
[Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 09/04/2006] [Accepted: 09/05/2006] [Indexed: 11/21/2022]
Abstract
The complexation of trans-resveratrol with beta-cyclodextrin (beta-CD) was investigated using reversed-phase liquid chromatography and mobile phases to which beta-CD was added. The decrease in the retention times with increasing concentrations of beta-CD (0-2.5 mM) showed that trans-resveratrol forms a 1:1 complex with beta-CD, while the apparent formation constants (K(F)) were strongly dependent of the water-methanol proportion of the mobile phase employed. A slight decrease in K(F) was observed at 50-55% water in the mobile phase but a large increase from 55 to 70% water. The values of K(F) for the trans-resveratrol-beta-CD interaction decreased when the temperature was raised from 20 to 37 degrees C. In order to gain information about the mechanism aspect of the trans-resveratrol affinity for beta-CD, the thermodynamic parameters of the complexation were obtained. Complex formation of trans-resveratrol with beta-CD (DeltaG degrees =-17.01 kJ/mol) is largely driven by enthalpy (DeltaH degrees = -30.62 kJ/mol) and slightly entropy changes (DeltaS degrees = -45.68 J/mol K).
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