Eisenreich W, Menhard B, Hylands P J, Zenk M H, Bacher A
Institut für Organische Chemie und Biochemie, Technische Universität München, Germany.
Proc Natl Acad Sci U S A. 1996 Jun 25;93(13):6431-6. doi: 10.1073/pnas.93.13.6431.
A cell culture of Taxus chinensis was established to produce the diterpene 2alpha,5alpha,10beta,14beta-tetra-acetoxy4 ++ +(20),11-taxadiene (taxuyunnanine C) in 2.6% (dry weight) yield. The incorporation of [U-13C6]glucose, [1-13C]glucose, and [1,2-13C2]acetate into this diterpene was analyzed by NMR spectroscopy. Label from [1,2-13C2]acetate was diverted to the four acetyl groups of taxuyunnanine C, but not to the taxane ring system. Label from [1-13C]glucose and [U-13C6]glucose was efficiently incorporated into both the taxane ring system and the acetyl groups. The four isoprenoid moieties of the diterpene showed identical labeling patterns. The analysis of long-range 13C13C couplings in taxuyunnanine C obtained from an experiment with [U-13C6]glucose documents the involvement of an intramolecular rearrangement in the biosynthesis of the isoprenoid precursor. The labeling patterns are inconsistent with the mevalonate pathway. The taxoid data share important features with the alternative pathway of isoprenoid biosynthesis operating in certain eubacteria Rohmer, M., Knani, M., Simonin, P., Sutter, B. & Sahm, H. (1993) Biochem. J. 295, 517-524].
建立了中国红豆杉细胞培养体系，以2.6%（干重）的产率生产二萜2α,5α,10β,14β-四乙酰氧基-4(20),11-紫杉二烯（云南紫杉碱C）。通过核磁共振光谱分析了[U-13C6]葡萄糖、[1-13C]葡萄糖和[1,2-13C2]乙酸掺入该二萜的情况。[1,2-13C2]乙酸的标记进入了云南紫杉碱C的四个乙酰基，但未进入紫杉烷环系统。[1-13C]葡萄糖和[U-13C6]葡萄糖的标记有效地掺入了紫杉烷环系统和乙酰基。二萜的四个异戊二烯部分显示出相同的标记模式。通过[U-13C6]葡萄糖实验获得的云南紫杉碱C中远程13C-13C偶合分析证明了异戊二烯前体生物合成中分子内重排的参与。标记模式与甲羟戊酸途径不一致。紫杉烷类数据与某些真细菌中运行的异戊二烯生物合成替代途径具有重要共同特征[罗默，M.，克纳尼，M.，西蒙宁，P.，萨特，B.和萨姆，H.（1993年）《生物化学杂志》295，517 - 524]。
