Antioxidant properties of prunes (Prunus domestica L.) and their constituents

Issue title: The Proceedings of the 3rd International Conference on Food Factors (ICoFF 03)

Article type: Research Article

Authors: Kayano, Shin-ichi^; | Kikuzaki, Hiroe | Yamada, Naoko Fukutsuka^; | Aoki, Asuka | Kasamatsu, Kumi | Yamasaki, Yuka | Ikami, Takao | Suzuki, Tomoo | Mitani, Takahiko^; | Nakatani, Nobuji^;

Affiliations: Research and Development Institute, MIKI Corporation, 12-4, Naruohama 3, Nishinomiya 663-8142, Japan | Division of Food and Health Sciences, Graduate School of Human Life Science, Osaka City University, 3-138, Sugimoto 3, Sumiyoshi, Osaka 558-8585, Japan | Institute of Advanced Technology, Kinki University, 14-1, Minamiakasaka, Kainan, Wakayama 642-0017, Japan | The University of the Air, 2-11, Wakaba, Mihama-ku, Chiba, 261-8586, Japan

Note: [] Corresponding author. Tel.: +81 6 6605 2812; Fax: +81 6 6605 3086; E-mail: [email protected]

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, O_2^- 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.

Keywords: prunes (Prunus domestica L.), oxygen radical absorbance capacity (ORAC), HPLC, chromanon, abscisic acid related compounds, bipyrrole, hydroxycinnamic acids, benzoic acids, coumarins, lignans, flavonoid

Journal: BioFactors, vol. 21, no. 1-4, pp. 309-313, 2004