27 罹病ナス科植物フィトアレキシン類の生合成研究

概要

論文の詳細を見る
The present paper describes biosynthetic studies on phytoalexins produced in diseased potato tubers (S. demissum×S. tuberosum), using synthetic (±)-[8,8-^2H_2]solavetivone (2a) and (-)-[12,12-^2H_2]rishitin (1a). The result summarized in Scheme 5 indicates that (i) natural (-)-(2) is metabolized into (-)-(1) via (+)-lubimin (16) and (+)-oxylubimin (17), while synthetic (+)-(1) does not undergo such enzymatic reactions, (ii) (-)-(2) would be a key intermediate for formation of (-)-(1) and (-)-phytuberin (3), two major phytoalexins in potato, (iii) (-)-(1) is metabolized separately into rishitin M-1 (4), M-2 (5), and M-3 (14) [and M-4 (15)], (iv) transformation of (-)-(1) into (-)-(5) in vivo proceeds in stereospecific manner, when the NIH shift and the deuterium isotopic effect in chemical shift were observed, and (v) the D_2-content of stress metabolites formed on incubation of the labelled compounds (2a) and (1a) (both D_2-content, ca. 100%) decreased clearly, indicating that some of the stress compounds are a stress itself, i.e., rishitin produces rishitin. Detailed examination of the deuterium content leads us to propose that phytoalexins accumulate in the area where phytoalexins are produced ("product-staying hypothesis" rather than currently accepted "transportation hypothesis").
天然有機化合物討論会の論文
1982-09-10