Host-guest interaction of 13-cyclodextrin with isomeric ursolicacid and oleanolic acid＂ physicochemical characterization andmolecular modeling study

• Published in: 生物医学研究杂志：英文版 Vol. 31; no. 5; pp. 395 - 407
• Main Author: Yuan Huang;Peng Quan;Yongwei Wang;Dongsheng Zhang;Mingwan Zhang;Rui Li;Nan Jiang
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: acid; host-guest; interaction; modeling; molecular; oleanolic; ursolic; β-cyclodextrin
• ISSN: 1674-8301

Ursolic acid （UA） and oleanolic acid （OA） are insoluble drugs. The objective of this study was to encapsulate theminto β-cyclodextrin （13-CD） and compare the solubility and intermolecular force of β-CD with the two isomerictriterpenic acids. The host-guest interaction was explored in liquid and solid state by ultraviolet-visible absorption, 1 HNMR, phase solubility analysis, and differential scanning calorimetry, X-ray powder diffractometry, and molecularmodeling studies. Both experimental and theoretical studies revealed that β-CD formed 1：1 water soluble inclusioncomplexes and the complexation process was naturally favorable. In addition, the overall results suggested that ring Ewith a carboxyl group of the drug was encapsulated into the hydrophobic CD nanocavity. Therefore, a clear differentinclusion behavior was observed, and UA exhibited better affinity to β-CD compared with OA in various media dueto little steric interference, which was beneficial to form stable inclusion complex with β-CD and increase its watersolubility effectively.