Article Sidebar
Published:
Jan 9, 2015Keywords:
Article Details
Submission of a manuscript to this journal is a representation that the manuscript has not been published previously and is not under consideration for publication elsewhere.
All authors named in each manuscript would be required to sign a form (to be supplied by the Editor) so that they may retain their copyright in the article but to assign to us (the Publishers) and its licensees in perpetuity, in all forms, formats and media (whether known or created in the future) to (i) publish, reproduce, distribute, display and store the contribution, (ii) translate the contribution into other languages, create adaptations, reprints, include within collections and create summaries, extracts and/or abstracts of the contribution, (iii) create any other derivative works(s) based on the contribution, (iv) to exploit all subsidiary rights in the contribution, (v) the inclusion of electronic links from the contribution to third party material where-ever it may be located, and (vi) license any thrid party to do any or all of the above.
Main Article Content
Inclusion Mechanism and Heat Stability of the Complex of 4'-Hydroxychalcone and Hydroxypropyl-β-Cyclodextrin
Abstract
Purpose: To study the inclusion mechanism and heat stability of the complex formed between 4'- hydroxychalcone and hydroxypropyl-β-cyclodextrin (HP-β-CD)
Methods: The inclusion mechanism of the complex of 4'-hydroxychalcone and HP-β-CD was investigated by phase solubility method. The physicochemical properties of the complex were evaluated by Fourier transform infrared spectroscopy (FT-IR) and x-ray diffractometry (XRD) while the heat stability of the complex was measured by thermogravimetric/differential scanning calorimetry (TG/DSC).
Results: The stability constants of the complexes were higher than those of β-CD at all temperatures. For the formation of the complex, Gibbs energy (-16.87 KJ/mol at 20 °C) was negative, and positive entropy (31.15 KJ/mol) along with a slightly positive enthalpic change (163.89 J/mol) was also found. IR and XRD analysis showed that the physical phase of 4-hydroxylchalcone was changed and completely dispersed in HP-β-CD while TG/DSC data indicate that the starting decomposition temperature of 4'- hydroxychalcone (200 °C) was significantly enhanced to 397 °C due to the formation of inclusion complex with HP-β-CD in the solid state.
Conclusion: The stability constant of HP-β-CD for 4'-hydroxychalcone is higher than that of β-CD. The inclusion is a spontaneous process, driven by hydrophobic forces. The heat stability of 4’- hydroxychalcone is significantly enhanced by complexing with HP-β-CD.
Keywords: 4'-Hydroxychalcone, Hydroxypropyl-β-cyclodextrin, Inclusion complex, Phase solubility, Thermogravimetry, Differential scanning calorimetry
