A solid‐state 17O NMR study of L ‐phenylalanine and L ‐valine hydrochlorides
A solid‐state 17O NMR study of L ‐phenylalanine and L ‐valine hydrochlorides
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L-苯丙氨酸和L-缬氨酸盐酸盐的固态17O NMR研究
DOI：
10.1002/mrc.2167
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发表时间：
2008
影响因子：
2
通讯作者：
T. Yamazaki
中科院分区：
文献类型：
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作者：
Kazuhiko Yamada;T. Shimizu;S. Ohki;T. Yamazaki
我们对多晶氨基酸盐酸盐中α-COOH基的氧-17化学屏蔽张量和电场梯度张量进行了实验研究。通过对[17O]-L-苯丙氨酸盐酸盐和[17O]-L-缬氨酸盐酸盐的17O魔角旋转(MAS)谱和9.4、11.7、16.4和21.8T的稳态核磁共振谱的分析，确定了包括两个核磁共振张量之间的相对取向的17O CS和EFG张量。计算得到羰基和羟基氧原子的四极耦合常数和CS张量的跨度分别为8.41~8.55 MHz和7.35~7.41 MHz，548~570ppm和225~231ppm。用密度泛函理论(DFT)对氢键模型进行了大量的量子化学计算。结果表明，卤素离子的氢键距离对17O核磁共振张量的依赖行为与水分子不同。版权所有©2008 John Wiley&Sons，Ltd.
We have presented an experimental investigation of the oxygen‐17 chemical shielding (CS) and electric‐field‐gradient (EFG) tensors for α‐COOH groups in polycrystalline amino acid hydrochlorides. The 17O CS and EFG tensors including the relative orientations between the two NMR tensors are determined in [17O]‐L‐phenylalanine hydrochloride and [17O]‐L‐valine hydrochloride by the analysis of the 17O magic‐angle‐spinning (MAS) and stationary NMR spectra obtained at 9.4, 11.7, 16.4, and 21.8 T. The quadrupole coupling constants (CQ) and the span of the CS tensors are found to be 8.41–8.55 MHz and 7.35–7.41MHz, and 548–570 ppm and 225–231 ppm, for carbonyl and hydroxyl oxygen atoms, respectively. Extensive quantum chemical calculations using density functional theory (DFT) have been also carried out for a hydrogen‐bonding model. It is demonstrated that the behavior of the dependence of hydrogen‐bond distances on 17O NMR tensors for the halogen ions is different from those for the water molecule. Copyright © 2008 John Wiley & Sons, Ltd.
生物固体中的固态 170 NMR：氨基酸和肽的高效 170 标记。
DOI：
--
发表时间：
2007
期刊：
Chemistry Letters 36(1)
影响因子：
--
作者：
Yamada;Kazuhiko
通讯作者：
Kazuhiko