期刊
PHYTOCHEMISTRY
卷 62, 期 1, 页码 101-107出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/S0031-9422(02)00444-2
关键词
pear; Pyrus ussuriensis Maxim.; Rosaceae (III); Erwinia amylovora; antibacterial activity; benzoquinone; arbutin; hydroquinone; bacterial shoot blight disease
Aqueous extracts of the tissue of succulent young shoots of the pear Pyrus spp. exhibited strong antibacterial activity against the bacterium Erwinia amylovora bv. 4. This activity was investigated quantitatively by a newly developed bioassay method. It was found that the activity changed with the age of the tissue. Extracts of the youngest leaves and stems from the shoot tops showed the strongest activity, and the activity decreased with age of the leaves and stems. The activity also changed with increase in time after preparation of the extract, increasing rapidly in the first hour after preparation, reaching a maximum at about 4 h, and then decreasing slowly. The substance essential for the antibacterial activity was isolated from the extract by steam distillation in vacuo and through charcoal powder column chromatography. It was identified as benzoquinone (2,5-cyclohexadiene-1,4-dione) by NMR-spectra, mass spectra and HPLC analysis. The phenolic metabolism from arbutin to hydroquinone and then to benzoquinone in the aqueous extracts was analyzed quantitatively by HPLC. The changes in the contents of benzoquinone in the extracts of leaves and stems with tissue aging and with increase in time after preparation of the extracts paralleled the changes in antibacterial activity as determined by the quantitative bioassay. (C) 2003 Elsevier Science Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据