Elucidation of the mechanism of complexation between oncocalyxone A and cyclodextrins by isothermal titration calorimetry and molecular modeling
| Autor: | C.T. Tavares, Nereide S. Santos-Magalhães, Alejandro Ayala, Marcelo Zaldini Hernandes, Rafael Matos Ximenes, Marcelo M. Rabello, Francisco Humberto Xavier-Júnior, Beatriz Pinheiro Bezerra, Otília Deusdênia L. Pessoa |
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| Rok vydání: | 2019 |
| Předmět: |
Molecular model
Supramolecular chemistry Isothermal titration calorimetry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Gibbs free energy Hydrophobic effect chemistry.chemical_compound symbols.namesake chemistry Docking (molecular) Computational chemistry Materials Chemistry symbols Molecule Hydroxymethyl Physical and Theoretical Chemistry 0210 nano-technology Spectroscopy |
| Zdroj: | Journal of Molecular Liquids. 274:165-172 |
| ISSN: | 0167-7322 |
| DOI: | 10.1016/j.molliq.2018.10.129 |
| Popis: | The physicochemical stability and bioavailability of oncocalyxone A (onco A), a quinone isolated from Auxemma oncocalyx tree, could be improved by supramolecular inclusion complexes with cyclodextrins (CDs). The aim of this study was thus to elucidate the complexation of onco A with different CDs using isothermal titration calorimetry (ITC) and molecular modeling. Data from the most favorable host:guest interaction made it possible to obtain onco A:HP-γ-CD inclusion complex, which was characterized by FTIR, 1HNMR, DSC and TG. Experimental results showed that onco A tends to interact more favorably with HP-γ-CD (K = 3175 M−1) with the most favorable Gibbs free energy (ΔG = −19.98 kJ.mol−1). Thermodynamic analysis indicates that the formation of the inclusion complex was entropy-driven (-TΔS = −19.54 kJ.mol−1), associated mainly with the hydrophobic interactions and release of water molecules from the cavity of the CD. Taken together, physicochemical analysis showed host:guest intermolecular interactions between onco A and the cavity of the HP-γ-CD, thereby confirming the formation of the inclusion complex. Moreover, molecular docking results showed two main orientations in which the interaction of the hydroxyl group and a hydroxymethyl group at the wider rim of the HP-γ-CD was more stable (average docking energy of −7.3 kcal/mol) than the one involving the methoxy group with two carbonyl groups at the wider rim (−7.1 kcal/mol). In conclusion, onco A:HP-γ-CD inclusion complex based on results of rational approaches was obtained for use in for further pharmaceutical application in drug delivery systems in cancer therapy. |
| Databáze: | OpenAIRE |
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