Conformational analysis of (+)-germacrene A by variable-temperature NMR and NOE spectroscopy
Conformational analysis of (+)-germacrene A by variable-temperature NMR and NOE spectroscopy
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DOI：
10.1016/j.tet.2007.04.037
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发表时间：
2007-08-06
期刊：
影响因子：
2.1
通讯作者：
Coates, Robert M.
中科院分区：
文献类型：
--
作者：
Faraldos, Juan A.;Wu, Shuiqin;Coates, Robert M.
(+)- Germacrene A 是倍半萜生物合成的重要中间体，以纯品形式从基因工程酵母中分离出来，并通过色谱特性（TLC、GC）、MS、旋光度、UV、IR、H-1 NMR 和 C-13 NMR 数据进行表征。 CDCl3 中的变温 500 MHz H-1 NMR 谱表明，在普通探针温度（25 摄氏度）或以下时，这种柔性环癸二烯环以三种 NMR 可区分的构象异构体的形式存在，其比例约为 5:3:2。通过 H-1 NMR 数据比较、NOE 实验和邻位偶联来确定构象异构体结构如下：1a（52%，UU）、1b（29% UD）和 1c（19%，DU）。 (c) 2007 Elsevier Ltd. 保留所有权利。
(+)- Germacrene A, an important intermediate in sesquiterpene biosynthesis, was isolated in pure form from a genetically engineered yeast and was characterized by chromatographic properties (TLC, GC), MS, optical rotation, UV, IR, H-1 NMR, and C-13 NMR data. Variable-temperature 500 MHz H-1 NMR spectra in CDCl3 showed that this flexible cyclodecadiene ring exists as three NMR-distinguishable conformational isomers in a ratio of about 5: 3: 2 at or below ordinary probe temperature ( 25 degrees C). The conformer structures were assigned by H-1 NMR data comparisons, NOE experiments, and vicinal couplings as follows: 1a (52%, UU), 1b (29% UD), and 1c (19%, DU). (c) 2007 Elsevier Ltd. All rights reserved.