title: Experimental and Theoretical Investigations on the Supermolecular Structure of Isoliquiritigenin and 6-O-α-D-Maltosyl-β-cyclodextrin Inclusion Complex.
abstract: Isoliquiritigenin (ILTG) possesses many pharmacological properties. However, its poor solubility and stability in water hinders its wide applications. The solubility of bioactive compounds can often be enhanced through preparation and delivery of various cyclodextrin (CD) inclusion complexes. The 6-O-α-D-maltosyl-β-CD (G2-β-CD), as one of the newest developments of CDs, has high aqueous solubility and low toxicity, especially stable inclusion characteristics with bioactive compounds. In this work, we for the first time construct and characterize the supermolecular structure of ILTG/G2-β-CD by scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffractometry (XRD). The solubility of ILTG in water at 25 °C rises from 0.003 to 0.717 mg/mL by the encapsulation with G2-β-CD. Our experimental observations on the presence of the ILTG/G2-β-CD inclusion complex are further supported by the ONIOM(our Own N-layer Integrated Orbital molecular Mechanics)-based QM/MM (Quantum Mechanics/Molecular Mechanics) calculations, typically substantiating these supermolecular characteristics, such as detailed structural assignments, preferred binding orientations, selectivity, solvent effects, interaction energies and forces of the ILTG/G2-β-CD inclusion complex. Our results have elucidated how ILTG interacts with G2-β-CD, demonstrating the primary host-guest interactions between ILTG and G2-β-CD, characterized by hydrogen bonds, hydrophobic interactions, electrostatic forces, and conformational effects, are favored for the formation of the ILTG/G2-β-CD inclusion.
authors.affiliation: School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China. lb55@hist.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China. liubenguo@hist.edu.cn.
authors.forename: Benguo
authors.initials: B
authors.lastname: Liu
authors.affiliation: School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China. ljq15937322777@gmail.com.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Biorheological Science and Technology, Ministry of Education, School of Bioengineering, Chongqing University, Chongqing 400044, China. 20131902032@cqu.edu.cn.
authors.forename: Huizhi
authors.initials: H
authors.lastname: Xiao
authors.affiliation: School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China. wangjunyi21@gmail.com.
authors.forename: Junyi
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Biorheological Science and Technology, Ministry of Education, School of Bioengineering, Chongqing University, Chongqing 400044, China. gzliang@cqu.edu.cn.
authors.forename: Guizhao
authors.initials: G
authors.lastname: Liang
mesh_terms: D047188:Chalcones / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D046911:Macromolecular Substances / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D047188:Chalcones; D046911:Macromolecular Substances; D047392:beta-Cyclodextrins; D014867:Water; C075170:6-O-maltosyl-beta-cyclodextrin; C040920:isoliquiritigenin
keywords: 6-O-α-D-Maltosyl-β-CD; ONIOM calculation; inclusion complex; isoliquiritigenin