title: Exploring host-guest interactions of sulfobutylether-β-cyclodextrin and phenolic acids by chemiluminescence and site-directed molecular docking.
abstract: We have developed a rapid method that allows us to characterize the binding interaction of sulfobutylether-β-cyclodextrin (SBE-β-CD) with five therapeutically important phenolic acids: ferulic acid, caffeic acid, gallic acid, protocatechuic acid, and vanillic acid. The method utilizes a flow-injection chemiluminescence (FI-CL) technique that relies on the inhibition of a cyclodextrin-luminol chemiluminescence (CL) by increasing amounts of the phenolic acids (PAs). This loss of CL with increasing amounts of PAs fits the equation lg[(I0-Is)/Is]=lgKPAs+nlg[PAs], allowing calculation of the binding constant (KPAs) and stoichiometric ratio (n). The five phenolic acids and SBE-β-CD formed complexes with a stoichiometric ratio of 1:1. The binding constants were on the order of 10(7) M(-1). These results showed a good correlation with the scores calculated by molecular docking. Further investigation by site-directed molecular docking and linear correlation analysis revealed that PAs entered the larger cavity of SBE-β-CD and the formation constants mainly depended on the number of hydrogen bond acceptors in the PAs structures. All these results indicate that the CL-based affinity method can be used for direct determination of host-guest inclusion interactions and has great potential to become a reliable alternative for quantitatively studying host-guest binding and drug-protein interactions.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China; College of Chemistry & Chemical Engineering, Xi'an Shiyou University, Xi'an 710065, China.
authors.forename: Xunyu
authors.initials: X
authors.lastname: Xiong
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an 710069, China.
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China. Electronic address: songzhenghua@hotmail.com.
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Song
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002236:Carbohydrate Conformation; D062385:Hydroxybenzoates / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D008163:Luminescent Measurements / Q000379:methods*; D062105:Molecular Docking Simulation; D047392:beta-Cyclodextrins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D062385:Hydroxybenzoates; D047392:beta-Cyclodextrins; C093196:SBE4-beta-cyclodextrin; C017616:phenolic acid
keywords: Chemiluminescence; Luminol; Molecular docking; Phenolic acids