Hampel Daniela, Mosandl Armin, Wüst Matthias
Institut für Lebensmittelchemie, Johann Wolfgang Goethe-Universität, Marie-Curie-Strasse 9, D-60439 Frankfurt/Main, Germany.
Phytochemistry. 2005 Feb;66(3):305-11. doi: 10.1016/j.phytochem.2004.12.010.
The biosynthesis of the monoterpenes terpinolene and myrcene and the sesquiterpene beta-caryophyllene in roots and leaves of two carrot varieties (Daucus carota L. cultivars Bolero and Kazan) were investigated by in vivo feeding experiments with [5,5-2H2]-mevalonic acid lactone (d2-MVL) and [5,5-2H2]-1-deoxy-D-xylulose (d2-DOX). The volatiles of the tissues were extracted by stir bar sorptive extraction and analyzed using thermal desorption-multidimensional gas chromatography-mass spectrometry. The experiments demonstrate independent de novo-biosynthesis of terpenoids in carrot roots and in carrot leaves. In both plant tissues monoterpenes are biosynthesized exclusively via the 1-deoxy-D-xylulose/2-C-methyl-D-erythritol-4-phosphate (DOXP/MEP) pathway, whereas sesquiterpenes are generated by the classical mevalonic acid pathway as well as by the DOXP/MEP route. A more detailed investigation of carrot root tissues revealed that the biosynthesis of terpenes is mainly localized in the phloem. Nevertheless, in xylem a de novo-biosynthesis of terpenes was detectable as well, even in the absence of oil ducts in this tissue.
通过用[5,5-2H₂]-甲羟戊酸内酯（d₂-MVL）和[5,5-2H₂]-1-脱氧-D-木酮糖（d₂-DOX）进行体内饲喂实验，研究了两个胡萝卜品种（胡萝卜变种Bolero和Kazan）根和叶中单萜类化合物萜品油烯和月桂烯以及倍半萜类化合物β-石竹烯的生物合成。通过搅拌棒吸附萃取法提取组织中的挥发物，并使用热脱附-多维气相色谱-质谱联用仪进行分析。实验证明胡萝卜根和叶中萜类化合物可独立从头合成。在这两种植物组织中，单萜类化合物仅通过1-脱氧-D-木酮糖/2-C-甲基-D-赤藓糖醇-4-磷酸（DOXP/MEP）途径生物合成，而倍半萜类化合物则通过经典的甲羟戊酸途径以及DOXP/MEP途径生成。对胡萝卜根组织更详细的研究表明，萜类化合物的生物合成主要定位于韧皮部。然而，即使该组织中没有油管，在木质部中也可检测到萜类化合物的从头合成。
