Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound.

Joana M Pais,Susana S Braga,Maria João Barroca,Filipe A Almeida Paz,Maria Paula M Marques

doi:10.3762/bjoc.13.212

Abstract

Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD), Raman, infrared and 13C{1H} CP-MAS NMR spectroscopies, and thermal analysis (TGA) to verify fisetin inclusion and to present a hypothetical structural arrangement for the host–guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

Highlights

Flavonoids, natural compounds with numerous beneficial actions on human health, including antioxidant [1], anti-inflammatory [2,3], anti-atherosclerotic [4,5], antidiabetic [6] and antitumor activities [7], are presently receiving much attention
The powder X-ray diffraction (PXRD) of the rehydrated sample reveals the presence of a new phase which contains no traces of crystallites of either γ-CD heptahydrate or pure fisetin (Figure 1)
Note the good similarity between the diffraction envelope of the recrystallized γ-CD·fisetin and the diffractogram calculated from the atomic coordinates of a model inclusion complex, γ-CD–12-crown-4 ether (trace (d) in Figure 1) [31]

Summary

Introduction

Flavonoids, natural compounds with numerous beneficial actions on human health, including antioxidant [1], anti-inflammatory [2,3], anti-atherosclerotic [4,5], antidiabetic [6] and antitumor activities [7], are presently receiving much attention. Studies focus on the elucidation of their biomolecular targets and on their applications as medicinal supplements [8] and in food fortification [9]. Examples include their content in cocoa powder [10], grains like rice, maize and wheat [11] and bread [12]. A flavonol, is among the most promising compounds of this class due to its broader range of activities.

Methods

Results

Conclusion