Huang Y, Quan P, Wang Y, Zhang D, Zhang M, Li R, Jiang N. Host-guest interaction of β-cyclodextrin with isomeric ursolic acid and oleanolic acid: physicochemical characterization and molecular modeling study.
J Biomed Res 2017;
31:395-407. [PMID:
28958995 PMCID:
PMC5706432 DOI:
10.7555/jbr.31.20160073]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 01/16/2017] [Indexed: 11/03/2022] Open
Abstract
Ursolic acid (UA) and oleanolic acid (OA) are insoluble drugs. The objective of this study was to encapsulate them into β-cyclodextrin (β-CD) and compare the solubility and intermolecular force of β-CD with the two isomeric triterpenic acids. The host-guest interaction was explored in liquid and solid state by ultraviolet-visible absorption,1 H NMR, phase solubility analysis, and differential scanning calorimetry, X-ray powder diffractometry, and molecular modeling studies. Both experimental and theoretical studies revealed that β-CD formed 1: 1 water soluble inclusion complexes and the complexation process was naturally favorable. In addition, the overall results suggested that ring E with a carboxyl group of the drug was encapsulated into the hydrophobic CD nanocavity. Therefore, a clear different inclusion behavior was observed, and UA exhibited better affinity to β-CD compared with OA in various media due to little steric interference, which was beneficial to form stable inclusion complex with β-CD and increase its water solubility effectively.
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