作者:Hirotaka YAMAMOTO、Masahiro INOMATA、Shinobu TSUCHIYA、Makoto NAKAMURA、Takeo UCHIYAMA、Takayuki ORITANI
DOI:10.1271/bbb.64.2075
日期:2000.1
A new biosynthetic intermediate of ABA, (2Z,4E)-γ-ionylideneacetaldehyde, was isolated from young mycelia of Cercospora cruenta. Under an 18O2 atmosphere, an oxygen atom of this endogenous aldehyde was exclusively labeled. Similarly, three 18O atoms were incorporated into the ABA molecule recovered after prolonged incubation; selectively labeled were one of the carboxyl oxygen atoms and the two on the ring portion of ABA. A feeding experiment with [1-13C]glucose proved the exclusive operation of the mevalonate pathway for the formation of both ABA and β-carotene. These results suggest that (2Z,4E)-γ-ionylideneacetaldehyde can be a key ABA biosynthetic intermediate formed by the oxidative cleavage of a carotenoid precursor.
从蕨类植物 Cercospora cruenta 的幼嫩菌丝体中分离出了一种新的 ABA 生物合成中间体 (2Z,4E)-γ-亚氨乙醛。在 18O2 气氛下,这种内源醛的一个氧原子被完全标记。同样,经过长时间培养后,ABA 分子中也含有三个 18O 原子;其中一个羧基氧原子和 ABA 环上的两个氧原子被选择性标记。用[1-13C]葡萄糖进行的喂养实验证明,甲羟戊酸途径是形成 ABA 和 β-胡萝卜素的唯一途径。这些结果表明,(2Z,4E)-γ-亚氨乙醛可能是类胡萝卜素前体氧化裂解形成的关键 ABA 生物合成中间体。