title: Target-guided isolation of polar antioxidants from Abelmoschus esculentus (L). Moench by high-speed counter-current chromatography method coupled with wavelength switching and extrusion elution mode.
abstract: An off-line two-dimensional high-speed counter-current chromatography strategy combined with the wavelength switching technique and extrusion elution mode was successfully developed and applied to the isolation of polar antioxidants from Abelmoschus esculentus (L).Moench. Target-guided by the result of 2,2-diphenyl-1-picrylhydrazyl screening assay, four antioxidants were obtained with purities over 90% through orthogonal high-speed counter-current chromatography separation. UV spectroscopy, mass spectrometry and1H NMR spectroscopy were employed to identify their structures, which were assigned as l-tryptophan, quercetin-3-O-sophoroside, 5,7,3',4'-tetrahydroxyflavonol-3-O-[β-d-rhamnopyranosil-(1→2)]-β-d-glucopyranoside, and quercetin-3-O-glucoside. Each monomer exhibited significant antioxidant activity. The results demonstrated that proposed method could be an effective approach to isolate bioactive compounds from complex natural products.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, China.
authors.forename: Ranhao
authors.initials: R
authors.lastname: Wang
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, China.|China Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, China.
authors.forename: Meiling
authors.initials: M
authors.lastname: Wang
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, China. xqchen@csu.edu.cn.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Chen
mesh_terms: D028483:Abelmoschus / Q000737:chemistry*; D000975:Antioxidants / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts
keywords: Abelmoschus esculentus (L).Moench; Antioxidants; Extrusion elution mode; High-speed counter-current chromatography; Wavelength switching