在质子化甘油酸中,质子迁移和分体变异
C F Rodriquez1, A Cunje, T Shoeib
1Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.
Journal of the American Chemical Society
|July 18, 2001
概括
质子迁移在质子化甘甘甘 (GGG) 中涉及小的能量障碍. 最稳定的质子位点是N端碳基氧,影响碎片化路径.
科学领域:
- 计算化学的计算化学
- 物理化学 物理化学
- 生物物理化学 生物物理化学
背景情况:
- 甘氨酸甘氨酸甘氨酸 (GGG) 是一种具有生物相关性的三.
- 了解质子和碎片化对于质化学至关重要.
- 之前对GGG质子化的研究已经产生了不同的结果.
研究的目的:
- 为了研究质子迁移途径在质子化甘油甘油甘油 (GGG).
- 描述能量超表面,并确定关键点.
- 确定最有利的质子化位点和碎片化机制.
主要方法:
- 密度函数理论 (DFT) 使用B3LYP/6-31++G (d,p) 理论水平进行计算.
- 在GGG能量超表面上,对19个关键点 (11个最小点,8个点) 的表征.
- 对质子迁移和分裂的过渡状态结构和自由能量障碍的计算.
主要成果:
- 确定了11个稳定的质子化GGG异构体和8个过渡状态.
- 最有利的质子化位点是N端碳基氧,由O-H.N键稳定.
- 对于b(2) 离子形成的计算能量障碍是32.5kcal mol(-1).
- 计算的质子亲和度和基本度值与经过修订的实验数据非常一致.
结论:
- 在质子化GGG中,质子迁移的特点是小的个体自由能量障碍.
- 在N端碳酸氧的质子化在能量上受到青,导致特定的碎片化途径.
- 该研究为GGG质子亲和力和基本性提供了准确的计算数据,与实验发现保持一致.
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