title: Preparative isolation and purification of seven main antioxidants from Eucommia ulmoides Oliv. (Du-zhong) leaves using HSCCC guided by DPPH-HPLC experiment.
abstract: Seven antioxidants were purified from Eucommia ulmoides Oliv. leaves using HSCCC guided by DPPH-HPLC experiment. HSCCC was successfully used to separate target antioxidants by three runs with different solvent systems after D101 column chromatography fractionation. Ethyl acetate-n-butanol-water (1:2:3, v/v/v) was selected as the optimum solvent system to purify geniposidic acid. Ethyl acetate-ethanol-water (4:1:5, v/v/v) was used to isolate caffeic acid, chlorogenic acid and ferulic acid. While three flavonoids, quercetin-3-O-sambubioside, rutin and isoquercitrin were purified by petroleum ether-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v). The structures were identified by MS and NMR. Antioxidant activities were assessed, and compounds 2-7 showed strong antioxidant activities. This is the first report about separation of antioxidants from E. ulmoides leaves by HSCCC. The results indicated that the combinative methods using DPPH-HPLC and HSCCC could be widely applied for screening and isolation of antioxidants from complex extracts.
authors.affiliation: Department of Integrated Traditional Chinese and Western Medicine, Key Laboratory of Traditional Chinese Medicine Gan Organ of SATCM, Central South University, Xiangya Hospital, Changsha 410008, PR China.
authors.forename: Xingping
authors.initials: X
authors.lastname: Dai
authors.forename: Qiong
authors.initials: Q
authors.lastname: Huang
authors.forename: Boting
authors.initials: B
authors.lastname: Zhou
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Gong
authors.forename: Zhaoqian
authors.initials: Z
authors.lastname: Liu
authors.forename: Shuyun
authors.initials: S
authors.lastname: Shi
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification*; D001713:Biphenyl Compounds; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003377:Countercurrent Distribution / Q000379:methods*; D031283:Eucommiaceae / Q000737:chemistry*; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification*; D018515:Plant Leaves / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl