• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Toward Closing the Gap between Hexoses and N-Acetlyhexosamines: Experimental and Computational Studies on the Collision-Induced Dissociation of Hexosamines
【24h】

Toward Closing the Gap between Hexoses and N-Acetlyhexosamines: Experimental and Computational Studies on the Collision-Induced Dissociation of Hexosamines

机译：靠近己糖和N-乙酰脲蛋白质之间的差距：对冬虫胺碰撞诱导的解离的实验和计算研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Motivated by the fundamental difference in the reactivity of hexoses and N-acetylhexosamines under collision-induced dissociation (CID) mass spectrometry conditions, we have investigated the CID of two hexosamines, glucosamine (GlcN) and galactosamine (GalN), experimentally and computationally. Both hexosamines undergo ring-opening and then dissociate via the (0,2)A and the (0,3)A (X-0,X-3) cross-ring cleavage channels. The preference for the ring-opening is similar to the behavior of N-acetylhexosamines and explains why the two anomers of the same sugar give the same mass spectrum. While the spectrum for GlcN is dominated by the (0,2)A signal, the signal intensities for both (0,2)A and the (0,3)A (X-0,X-3) dissociation channels are comparable for GalN, which allows GlcN and GalN to be distinguished easily. Calculations at MP2 level of theory indicate that this is related to the differences in the relative barrier heights for the (0,2)A and the (0,3)A (X-0,X-3) cross-ring cleavage channels. This, in return, reflects the circumstance that the (0,2)A cross-ring cleavage barriers are different for the two sugars, while the barriers of all other dissociation channels are comparable. While the mechanisms of the cross-ring dissociation channels of hexoses are well described using the retro-aldol mechanism in the literature, this study proposes a new mechanism for the (0,3)A (X-0,X-3) cross-ring cleavage of hexosamines that involves the formation of an epoxy intermediate or a zwitterionic intermediate.
机译：在碰撞诱导的解离（CID）质谱条件下，己糖和N-乙酰己胺反应性的基本差异激励，我们研究了两种己糖胺，葡糖胺（GLCN）和半乳糖胺（GALN）的CID，实验和计算。六氧肟胺经过开环，然后通过（0,2）A和（0,3）A（X-0，X-3）交叉环切割通道解离。开环的偏好类似于N-乙酰己胺的行为，并解释了为什么相同糖的两个异构体提供相同的质谱。虽然GLCN的频谱由（0,2）信号主导，但是（0,2）A和（0,3）A（X-0，X-3）解离通道的信号强度对于Galn，允许Glcn和Galn轻松区分。 MP2理论水平的计算表明，这与（0,2）A和（0,3）A（X-0，X-3）交叉环切割通道的相对阻挡高度的差异有关。作为回报，反映了（0,2）横环裂解屏障对两种糖不同的情况，而所有其他离解通道的屏障是可比的。虽然使用文献中的retro-aldol机制，己烷串的交叉环解离通道的机制很好地描述，但是本研究提出了一种（0,3）A（x-0，x-3）交叉的新机制环瘤的环裂解，其涉及形成环氧中间体或两性离子中间体。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号