尼古丁的两个环之间的键之间的干扰
Jérôme Graton1, Tanja van Mourik, Sarah L Price
1Centre for Theoretical and Computational Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom.
Journal of the American Chemical Society
|May 8, 2003
概括
尼古丁是一种尼古丁.
科学领域:
- 生物化学 生物化学
- 计算化学计算化学
- 分子建模分子建模
背景情况:
- 尼古丁的生化运输和结合依赖于键.
- 存在两个不同的结位:化环和质子化化环.
- 这些部位在尼古丁相互作用中的独立性尚未完全理解.
研究的目的:
- 为了研究基尼古丁中结位点的独立性.
- 为了模拟尼古丁与水,二碳酸盐,和的相互作用.
- 评估这些相互作用对尼古丁结构和结合性的影响.
主要方法:
- 尼古丁集群的计算结构与各种分子 (水,碳酸,,,醇).
- 使用分子间异质原子-原子模型潜力探索潜在能量表面.
- 使用密度函数理论 (DFT) 进行完整的几何优化,以包括非添加效应.
主要成果:
- 尼古丁的pyrrolidine的质子化会影响pyridine环中的键.
- 双碳酸离子部分恢复了匹里丁环的结合能力.
- 和醇的相互作用不同,醇部分恢复了胺的能力.
- 第二个水分子诱导了尼古丁的显著形状变化.
结论:
- 尼古丁气结合点的独立性有限,挑战了传统的预测.
- 与阳离子和芳香分子的相互作用调节结能力.
- 结果为生物化学系统中的原子模型提供了基准.
相关概念视频
Interference and Diffraction
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
Nuclear Overhauser Enhancement (NOE)
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the nuclear Overhauser enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring spin-active...
Interference: Path Lengths
Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
Interference and Decay
Forgetting is a complex cognitive phenomenon influenced by several factors, among which interference and decay are particularly prominent. These processes explain why individuals often struggle to retrieve specific information from memory, leading to lapses in recall that can be observed in everyday situations.
Interference occurs when competing memories hinder the retrieval of particular information. It can be classified into two types: proactive and retroactive interference. Proactive...
Interference occurs when competing memories hinder the retrieval of particular information. It can be classified into two types: proactive and retroactive interference. Proactive...


