Artículos de revistas
Synthesis and spectral investigation of Al(III) catechin/beta-cyclodextrin and Al(III) quercetin/beta-cyclodextrin inclusion compounds
Fecha
2008Registro en:
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, v.70, n.1, p.154-161, 2008
1386-1425
10.1016/j.saa.2007.07.022
Autor
DIAS, Karina
NIKOLAOU, Sofia
GIOVANI, Wagner F. De
Institución
Resumen
Al-catechin/beta-cyclodextrin and Al-quercetin/beta-cyclodextrin (beta-CD) inclusion compounds were synthesized and characterized by IR, UV-vis, H-1 and C-13 NMR and TG and DTA analyses. Because quercetin is sparingly soluble in water, the stability constants of the Al-quercetin/beta-CD and Al-catechin/beta-CD compounds were determined by phase solubility studies. The A(L)-type diagrams indicated the formation of 1:1 inclusion compounds and allowed calculation of the stability constants. The thermodynamic parameters were obtained from the dependence of the stability constants on temperature and results indicated that the formation of the inclusion compounds is an enthalpically driven process. The thermal decomposition of the solid Al-quercetin/beta-CD and Al-catcchin/beta-CD inclusion compounds took place at different stages, compared with the respective precursors, proving that an inclusion complexation process really occurred. (C) 2007 Published by Elsevier B.V.