Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins
â-Cyclodextrins ( â - CDs), macrocyclic oligosaccharides formed by seven glucopyranose units, have a rigid lipophilic cavity and can form host - guest inclusion complexes with suitably sized hydrophobic molecules. Water content infl uences the structure of â - CDs and affects the chemical and physic...
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todo:paper_97808138_v_n_p149_Ponce2023-10-03T16:42:51Z Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins Ponce, P.A. Buera, M.P. Elizalde, B.E. β-Cyclodextrins - rigid lipophilic cavity cyclodextrins (CDs) - cyclic oligosaccharides consisting of glucose units DSC thermograms of complexes - disappearance of fusion peaks of thymol and cinnamaldehyde Inclusion complexes of thymol and cinnamaldehyde - coprecipitation method Sorption isotherms - standard isopiestic static-gravimetric method Water sorption - affecting stability Water-sorption properties - stability of inclusion complexes â-Cyclodextrins ( â - CDs), macrocyclic oligosaccharides formed by seven glucopyranose units, have a rigid lipophilic cavity and can form host - guest inclusion complexes with suitably sized hydrophobic molecules. Water content infl uences the structure of â - CDs and affects the chemical and physical stability of complexed compounds. This work investigated the relationship between the sorption characteristics of â - CDs and complexes formed with thymol and cinnamaldehyde and their release. The complexes were obtained by coprecipitation, fi ltered, freeze - dried, and stored at constant relative humidity (RH) in evacuated chambers (22% - 97%) at 25 ° C. The release of encapsulated compounds was determined after equilibration by differential scanning calorimetry (DSC) following the enthalpy of the fusion peak at 50 ° C (thymol) and 7.5 ° C (cinnamaldehyde). DSC thermograms of complexes after freeze drying showed the disappearance of fusion peaks of thymol and cinnamaldehyde, indicating complex formation. Water - sorption isotherms for â - CD and the complexes showed constant and low water sorption at an RH of less than 80%, and then the uptake of water increased abruptly. At 95% RH, the water adsorbed was in the order â - CD (12.5 mol water/mol â - CD) â - CD - thymol (8.5 mol water/mol complex) â - CD - cinnamaldehyde (7 mol water/mol complex). The guest molecules displaced water molecules from inside the cavity of â - CD. At an RH of less than 84%, thymol and cinnamaldehyde were not released. The percent of released compound abruptly increased from 84% RH, coinciding with the abrupt increase of water. Water sorption signifi cantly affected thymol and cinnamaldehyde complexes with â - CD, and complex stability was thus governed by the shape of the water -sorption isotherm. © 2010 Blackwell Publishing. Fil:Ponce, P.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Buera, M.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Elizalde, B.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. CHAP info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_97808138_v_n_p149_Ponce |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
β-Cyclodextrins - rigid lipophilic cavity cyclodextrins (CDs) - cyclic oligosaccharides consisting of glucose units DSC thermograms of complexes - disappearance of fusion peaks of thymol and cinnamaldehyde Inclusion complexes of thymol and cinnamaldehyde - coprecipitation method Sorption isotherms - standard isopiestic static-gravimetric method Water sorption - affecting stability Water-sorption properties - stability of inclusion complexes |
| spellingShingle |
β-Cyclodextrins - rigid lipophilic cavity cyclodextrins (CDs) - cyclic oligosaccharides consisting of glucose units DSC thermograms of complexes - disappearance of fusion peaks of thymol and cinnamaldehyde Inclusion complexes of thymol and cinnamaldehyde - coprecipitation method Sorption isotherms - standard isopiestic static-gravimetric method Water sorption - affecting stability Water-sorption properties - stability of inclusion complexes Ponce, P.A. Buera, M.P. Elizalde, B.E. Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins |
| topic_facet |
β-Cyclodextrins - rigid lipophilic cavity cyclodextrins (CDs) - cyclic oligosaccharides consisting of glucose units DSC thermograms of complexes - disappearance of fusion peaks of thymol and cinnamaldehyde Inclusion complexes of thymol and cinnamaldehyde - coprecipitation method Sorption isotherms - standard isopiestic static-gravimetric method Water sorption - affecting stability Water-sorption properties - stability of inclusion complexes |
| description |
â-Cyclodextrins ( â - CDs), macrocyclic oligosaccharides formed by seven glucopyranose units, have a rigid lipophilic cavity and can form host - guest inclusion complexes with suitably sized hydrophobic molecules. Water content infl uences the structure of â - CDs and affects the chemical and physical stability of complexed compounds. This work investigated the relationship between the sorption characteristics of â - CDs and complexes formed with thymol and cinnamaldehyde and their release. The complexes were obtained by coprecipitation, fi ltered, freeze - dried, and stored at constant relative humidity (RH) in evacuated chambers (22% - 97%) at 25 ° C. The release of encapsulated compounds was determined after equilibration by differential scanning calorimetry (DSC) following the enthalpy of the fusion peak at 50 ° C (thymol) and 7.5 ° C (cinnamaldehyde). DSC thermograms of complexes after freeze drying showed the disappearance of fusion peaks of thymol and cinnamaldehyde, indicating complex formation. Water - sorption isotherms for â - CD and the complexes showed constant and low water sorption at an RH of less than 80%, and then the uptake of water increased abruptly. At 95% RH, the water adsorbed was in the order â - CD (12.5 mol water/mol â - CD) â - CD - thymol (8.5 mol water/mol complex) â - CD - cinnamaldehyde (7 mol water/mol complex). The guest molecules displaced water molecules from inside the cavity of â - CD. At an RH of less than 84%, thymol and cinnamaldehyde were not released. The percent of released compound abruptly increased from 84% RH, coinciding with the abrupt increase of water. Water sorption signifi cantly affected thymol and cinnamaldehyde complexes with â - CD, and complex stability was thus governed by the shape of the water -sorption isotherm. © 2010 Blackwell Publishing. |
| format |
CHAP |
| author |
Ponce, P.A. Buera, M.P. Elizalde, B.E. |
| author_facet |
Ponce, P.A. Buera, M.P. Elizalde, B.E. |
| author_sort |
Ponce, P.A. |
| title |
Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins |
| title_short |
Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins |
| title_full |
Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins |
| title_fullStr |
Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins |
| title_full_unstemmed |
Water-Sorption Properties and Stability of Inclusion Complexes of Thymol and Cinnamaldehyde with β-Cyclodextrins |
| title_sort |
water-sorption properties and stability of inclusion complexes of thymol and cinnamaldehyde with β-cyclodextrins |
| url |
http://hdl.handle.net/20.500.12110/paper_97808138_v_n_p149_Ponce |
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AT poncepa watersorptionpropertiesandstabilityofinclusioncomplexesofthymolandcinnamaldehydewithbcyclodextrins AT bueramp watersorptionpropertiesandstabilityofinclusioncomplexesofthymolandcinnamaldehydewithbcyclodextrins AT elizaldebe watersorptionpropertiesandstabilityofinclusioncomplexesofthymolandcinnamaldehydewithbcyclodextrins |
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