title: Antioxidant properties of prunes (Prunus domestica L.) and their constituents.
abstract: Prunes contain large amounts of phenolics and show high antioxidant activity. The aim of this study is to clarify the contents of caffeoylquinic acid (CQA) isomers, and to estimate the contribution of these isomers to the antioxidant activity of prunes. Furthermore, structural elucidation and evaluation of antioxidant activity of prune components were also performed. CQA isomers in prunes were quantified by HPLC analysis, and it has become apparent that prunes contain relatively high amount of 4-O-caffeoylquinic acid. The contribution of CQA isomers to the antioxidant activity of prunes was revealed to be 28.4% on the basis of oxygen radical absorbance capacity (ORAC); hence, it was indicated that residual ORAC is dependent on unknown antioxidant components. Total 28 compounds were isolated and their structures were elucidated by NMR and MS analyses. Four abscisic acid related compounds, a chromanon, and a bipyrrole were novel. Each CQA isomer in prunes showed high antioxidant activities when measured by the oil stability index (OSI) method, O2- scavenging activity, and ORAC. Other isolated compounds such as hydroxycinnamic acids, benzoic acids, coumarins, lignans, and flavonoid showed high ORAC values. Furthermore, a novel chromanon indicated a remarkable synergistic effect on ORAC of CQA isomers.
authors.affiliation: Research and Development Institute, MIKI Corporation, 12-4, Naruohama 3, Nishinomiya 663-8142, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kayano
authors.forename: Hiroe
authors.initials: H
authors.lastname: Kikuzaki
authors.forename: Naoko Fukutsuka
authors.initials: NF
authors.lastname: Yamada
authors.forename: Asuka
authors.initials: A
authors.lastname: Aoki
authors.forename: Kumi
authors.initials: K
authors.lastname: Kasamatsu
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yamasaki
authors.forename: Takao
authors.initials: T
authors.lastname: Ikami
authors.forename: Tomoo
authors.initials: T
authors.lastname: Suzuki
authors.forename: Takahiko
authors.initials: T
authors.lastname: Mitani
authors.forename: Nobuji
authors.initials: N
authors.lastname: Nakatani
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D005511:Food Handling; D005609:Free Radicals; D007536:Isomerism; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification; D027861:Prunus / Q000737:chemistry*; D011801:Quinic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D013329:Structure-Activity Relationship
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D010636:Phenols; C472707:caffeoylquinic acid; D011801:Quinic Acid