Theoretical study of the interactions of β-cyclodextrin with 2′-hydroxyl-5′-methoxyacetophone and two of its isomers

• Published in: Journal of molecular liquids 2009-05, Vol.146 (1), p.15-22
• Main Authors: Xing, S.K., Zhang, C., Ai, H.Q., Zhao, Q., Zhang, Q., Sun, D.Z.
• Format: Article
• Language: English
• Subjects: Cyclodextrin; Equilibrium distribution; Inclusion complex; Molecular recognition; Mulliken charge population analysis
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2009.01.005

The inclusion process of 2′-hydroxyl-5′-methoxyacetophone (Hma) with β-cyclodextrin ( β-CD), as well as their other seven possible interaction types, was investigated theoretically. The data suggest that: (1) the inclusion complex formed by Hma entering into the cavity of β-CD from its wide side (the secondary hydroxyl group side) is more stable than that from its narrow side (the primary hydroxyl group side); (2) the formation of the inclusion complex is predicted to be an enthalpy-driven process in gas phase and an enthalpy–entropy co-driven process in aqueous solution, which is in accord with the experimental results; (3) other different interaction types between Hma and β-CD should be also possibly found experimentally due to their negative binding energy (Δ E) though their distributions differ greatly. At last, comparative study of the interactions of β-CD with Hma and its two isomers, paeonol (Pae) and acetovanillone (Ace), are investigated and their obvious differences in binding energy and enthalpy change suggest that the β-CD could identify the three isomers.