title: Simple detection method of powerful antiradical compounds in the raw extract of plants and its application for the identification of antiradical plant constituents.
abstract: A simple detection method for a powerful radical scavenging compound in a mixture containing a large variety of compounds, such as the raw extract of edible plants, was developed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the radical reagent. The method was established on the basis of the features of the typical chain-breaking antioxidation reaction mechanism, which suggests that the radical scavenging antioxidant should be converted to other stable nonradical compounds during the reaction. This method requires only a simple HPLC instrument, and the disappearance or decrease in the peak intensity, which is induced by the addition of DPPH. This change is monitored by the HPLC to detect the powerful radical scavenger from the complex mixture. The method was applied to the detection and identification of the most powerful antiradical compound in the extracts of three antioxidatively active plant extracts (Psidium guajava, Citrus depressa, and Hypericum chinense). The radical scavenging efficiency of a newly identified compound from H. chinense was also compared with that of Trolox and catechin using the method.
authors.affiliation: Faculty of Integrated Arts and Sciences, University of Tokushima, Tokushima 770-8502, Japan. masuda@ias.tokushimau.ac.jp
authors.forename: Toshiya
authors.initials: T
authors.lastname: Masuda
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Inaba
authors.forename: Tomomi
authors.initials: T
authors.lastname: Maekawa
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Takeda
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Katsuo
authors.initials: K
authors.lastname: Nakamoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Kuninaga
authors.forename: Saori
authors.initials: S
authors.lastname: Nishizato
authors.forename: Akira
authors.initials: A
authors.lastname: Nonaka
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D001713:Biphenyl Compounds; D002392:Catechin; D002839:Chromans; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002957:Citrus / Q000737:chemistry; D016166:Free Radical Scavengers / Q000032:analysis*; D020902:Hypericum / Q000737:chemistry; D007202:Indicators and Reagents; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D031647:Psidium / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002839:Chromans; D016166:Free Radical Scavengers; D007202:Indicators and Reagents; D010851:Picrates; D010936:Plant Extracts; D002392:Catechin; C004931:1,1-diphenyl-2-picrylhydrazyl; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid