title: HPLC coupled on-line to ESI-MS and a DPPH-based assay for the rapid identification of anti-oxidants in Butea superba.
abstract: A reversed-phase HPLC coupled on-line to a radical scavenging detection system and MS/MS was developed in order to combine separation, activity determination and structural identification of anti-oxidants in complex mixtures in one run. The sample was separated by HPLC and the eluate split into two flows. The major portion was fed into an electrospray ionisation MS/MS system, while the minor part was mixed with a free radical, 2,2'-diphenyl-1-picrylhydrazyl (DPPH), and the reaction determined spectrophotometrically. The negative peaks, which indicated the presence of anti-oxidant activity, were monitored by measuring the decrease in absorbance at 517 nm. The developed method was successfully applied to the identification of anti-oxidant compounds in a fraction, obtained by solid-phase extraction, of an extract of a Thai medicinal plant, Butea superba Roxb. The anti-oxidant compounds were separated and identified as procyanidin B2, (-)-epicatechin and procyanidin B5.
authors.affiliation: Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand.
authors.forename: N
authors.initials: N
authors.lastname: Nuengchamnong
authors.forename: C F
authors.initials: CF
authors.lastname: de Jong
authors.forename: B
authors.initials: B
authors.lastname: Bruyneel
authors.forename: W M A
authors.initials: WM
authors.lastname: Niessen
authors.forename: H
authors.initials: H
authors.lastname: Irth
authors.forename: K
authors.initials: K
authors.lastname: Ingkaninan
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D001713:Biphenyl Compounds; D031290:Butea / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006834:Hydrazines; D010851:Picrates; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D006834:Hydrazines; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl