title: Screening of lipase inhibitors from Scutellaria baicalensis extract using lipase immobilized on magnetic nanoparticles and study on the inhibitory mechanism.
abstract: Scutellaria baicalensis is a traditional Chinese medicinal plant possessing a wide variety of biological activities. In this work, lipase immobilized on magnetic nanoparticles (LMNPs) was used as solid phase extract absorbent for screening of lipase inhibitors from this plant. Three flavonoids were found to bind to LMNPs and were identified as baicalin, wogonin, and oroxylin A by liquid chromatography-mass spectrometry (HPLC-MS). Their IC50 values were determined to be 229.22 ± 12.67, 153.71 ± 9.21, and 56.07 ± 4.90 μM, respectively. Fluorescence spectroscopy and molecular docking were used to probe the interactions between these flavonoids and lipase. All the flavonoids quenched the fluorescence of lipase statically by forming new complexes, implying their affinities with the enzyme. The thermodynamic analysis suggested that van der Waals force and hydrogen bond were the main forces between wogonin and lipase, while hydrophobic force was the main force for the other two flavonoids. The results from a molecular docking study further revealed that all of them could insert into the pocket of lipase binding to a couple of amino acid residues.
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: Wan
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Xiao-Lan
authors.initials: XL
authors.lastname: Jiang
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China. yiming.liu@jsums.edu.|Department of Chemistry and Biochemistry, Jackson State University, 1400 Lynch St., Jackson, MS, 39217, USA. yiming.liu@jsums.edu.
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Liu
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Jin-Jie
authors.initials: JJ
authors.lastname: Hu
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liang
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China. liaoxun@cib.ac.cn.
authors.forename: Xun
authors.initials: X
authors.lastname: Liao
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000032:analysis* / Q000302:isolation & purification; D004800:Enzymes, Immobilized / Q000737:chemistry*; D008049:Lipase / Q000037:antagonists & inhibitors*; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D010936:Plant Extracts / Q000737:chemistry*; D031364:Scutellaria baicalensis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D053719:Tandem Mass Spectrometry; D013818:Thermogravimetry
chemical_list: D004791:Enzyme Inhibitors; D004800:Enzymes, Immobilized; D010936:Plant Extracts; D008049:Lipase
keywords: Fluorescence spectroscopy; Lipase inhibitors; Magnetic solid phase extraction; Molecular docking; Scutellaria baicalensis