title: Bioassay-guided preparative separation of angiotensin-converting enzyme inhibitory C-flavone glycosides from Desmodium styracifolium by recycling complexation high-speed counter-current chromatography.
abstract: A new strategy of the convergence of high-speed counter-current chromatography (HSCCC) and bioactive assay technique was developed for rapidly screening and separating the angiotensin-converting enzyme (ACE) inhibitors from the aerial parts of Desmodium styracifolium. Bioactivity-guided fractionation of the crude extract was first established to target the bioactive fractions based on HSCCC coupled with in vitro ACE inhibitory assay. Subsequently, the bioactive fractions were further separated by the recycling complexation HSCCC respectively, using 0.10 mol/L copper sulfate in the lower phase of two-phase solvent system composed of n-butanol/water (1:1, v/v). Five C-glycosylflavones, vicenin 2 (1), carlinoside (2), vicenin 1 (3), schaftoside (4) and vicenin 3 (5), were successfully obtained. Their chemical structures were identified using ESI-MS and NMR. All the isolates showed in vitro ACE inhibitory activity with the IC50 values between 33.62 and 58.37 μM. The results demonstrated that the established method was proposed as an excellent strategy to systematically screen and purify active compounds from traditional Chinese medicines.
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China.
authors.forename: Ying-Qi
authors.initials: YQ
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China.
authors.forename: Jian-Guang
authors.initials: JG
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Han
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China.
authors.forename: Jin-Fang
authors.initials: JF
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China. Electronic address: cpu_lykong@126.com.
authors.forename: Ling-Yi
authors.initials: LY
authors.lastname: Kong
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D007887:Fabaceae / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D047309:Flavones; D006027:Glycosides
keywords: Angiotensin-converting enzyme inhibitor; Bioactivity-guided fractionation; C-flavone glycosides; Desmodium styracifolium; High-speed counter-current chromatography