In vitro formation of the anthranoid scaffold by cell-free extracts from yeast-extract-treated Cassia bicapsularis cell cultures
作者:Iman A.M. Abdel-Rahman、Till Beuerle、Ludger Ernst、Afaf M. Abdel-Baky、Ezz El-Din K. Desoky、Amany S. Ahmed、Ludger Beerhues
DOI:10.1016/j.phytochem.2013.01.001
日期:2013.4
give the shunt products SEK4 and SEK4b. Here we report in vitro formation of the anthranoid scaffold by cell-free extracts from yeast-extract-treated Cassia bicapsularis cell cultures. Unlike field- and in vitro-grown shoots which accumulate anthraquinones, cell cultures mainly contained tetrahydroanthracenes, formation of which was increased 2.5-fold by the addition of yeast extract. The elicitor-stimulated
Anthranoid 骨架被认为是由八酮合酶 (OKS) 形成的,它是 III 型聚酮合酶 (PKS) 超家族的成员。重组 OKS 催化八个乙酰基单元逐步缩合形成线性八酮中间体,然而,该中间体被错误折叠和环化,得到分流产物 SEK4 和 SEK4b。在这里,我们报告了通过酵母提取物处理的决明子细胞培养物的无细胞提取物在体外形成类蒽醌支架。与积累蒽醌的田间和体外生长的芽不同,细胞培养物主要含有四氢蒽,通过添加酵母提取物,四氢蒽的形成增加了 2.5 倍。引发剂刺激的四氢蒽积累之前是大约。OKS 活动增加了 35 倍。将酵母提取物处理过的细胞培养物中的无细胞提取物与乙酰辅酶 A 和 [2-(14)C] 丙二酰辅酶 A 一起孵育,除了两种尚未确定的产品外,还会形成 torosachrysone(四氢蒽)和大黄素蒽酮。在没有乙酰辅酶 A 作为起始底物的情况下没有产物形成。为了确认酶产物的身份,无细胞提取物与乙酰辅酶