title: A 5,7-dimethoxyflavone/hydroxypropyl-β-cyclodextrin inclusion complex with anti-butyrylcholinesterase activity.
abstract: This study aimed to improve the water solubility of 5,7-dimethoxyflavone (5,7-DMF) isolated from Kaempferia parviflora by complexation with 2-hydroxypropyl-β-cyclodextrin (HPβ-CD). The phase solubility profile of 5,7-DMF in the presence of HPβ-CD was classified as AL-type and indicated a 1:1 mole ratio. Differential scanning colorimetry, X-ray diffraction, NMR and SEM analyses supported the formation of a 5,7-DMF/HPβ-CD inclusion complex involving the A ring of 5,7-DMF inside the HPβ-CD cavity. This is the first example of CD inclusion with the A ring of non-hydroxyl flavones. The stability and binding constants of the complexes were determined using the phase solubility and UV-vis absorption spectroscopy, respectively. The water solubility of 5,7-DMF was increased 361.8-fold by complexation with HPβ-CD and overcame the precipitation problem observed in aqueous buffers, such as during in vitro anti-butyrylcholinesterase activity assays. The 1:1 mole ratio of the 5,7-DMF/HPβ-CD complex showed a 2.7-fold higher butyrylcholinesterase inhibitory activity (in terms of the IC50 value) compared to the non-complexed compound.
authors.affiliation: Petrochemical and Polymer Science Program, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
authors.forename: Supachai
authors.initials: S
authors.lastname: Songngam
authors.forename: Mongkol
authors.initials: M
authors.lastname: Sukwattanasinitt
authors.forename: Krisana
authors.initials: K
authors.lastname: Siralertmukul
authors.forename: Pattara
authors.initials: P
authors.lastname: Sawasdee
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002091:Butyrylcholinesterase; D002626:Chemistry, Pharmaceutical; D002800:Cholinesterase Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D012995:Solubility; D047392:beta-Cyclodextrins / Q000494:pharmacology*
chemical_list: D002800:Cholinesterase Inhibitors; D005419:Flavonoids; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; C060298:5,7-dimethoxyflavone; D002091:Butyrylcholinesterase