核磁共振燃料 溶剂系统选择用于对流分离自然产品
Tao Chen1, Qiqi Wang2, Feilong Zhao3
1Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, PR China.
Talanta
|November 6, 2025
概括
核磁共振 (NMR) 为高性能液体染色学 (HPLC) 提供了一种强大的替代方案,用于选择自然产品逆流分离中的溶剂系统,特别是对于具有挑战性的异构体和吸收紫外线的化合物.
科学领域:
- 自然产品化学 自然产品化学
- 分析化学 分析化学
- 分离科学 分离科学
背景情况:
- 溶剂系统的选择对于自然产品的逆流分离至关重要,但具有挑战性.
- 高性能液体染色学 (HPLC) 仅限于分离缺少紫外线吸收的异构体或化合物.
- 核磁共振 (NMR) 为这些具有挑战性的分离提供了一个潜在的替代方案.
研究的目的:
- 利用NMR作为在逆流分离中选择溶剂系统的补充策略.
- 解决HPLC对异构体和非UV吸收自然产品的局限性.
- 为了证明NMR在复杂的天然产品混合物中的可行性.
主要方法:
- 从复杂的混合物中使用NMR进行质子信号的表征和量化.
- 使用量子力学自旋分析来提取单个组件的光谱信息.
- 确定用于溶剂系统优化的分区系数.
- 应用该方法来分离酸异构体和三烯酸盐素.
主要成果:
- 核磁共振成功地为混合物中的单个成分提供了光谱信息.
- 分割系数被准确地确定,有助于选择溶剂系统.
- 通过成功分离具有挑战性的自然产品示例来证明可行性.
- 对于没有紫外线吸收的同位素和化合物,NMR被证明是有效的.
结论:
- 核磁共振是HPLC的强大补充工具,用于在逆流分离中选择溶剂系统.
- 这种基于NMR的方法增强了复杂的自然产品的分离,包括异构体.
- 该方法扩大了对比电流分离的适用性,用于更广泛的自然化合物.
相关概念视频
Chemical Shift: Internal References and Solvent Effects
1.2K
In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
1.2K
Double Resonance Techniques: Overview
680
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...
680
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.7K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.7K
¹³C NMR: ¹H–¹³C Decoupling
1.7K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.7K
Capillary Electrophoresis: Applications
1.1K
Capillary electrophoretic separations offer various modes, each with unique applications. These modes include capillary zone electrophoresis, capillary gel electrophoresis, capillary array electrophoresis, capillary isoelectric focusing, capillary isotachophoresis, micellar electrokinetic chromatography, and capillary electrochromatography.
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...
1.1K
2D NMR: Overview of Homonuclear Correlation Techniques
604
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
COSY90 is the standard two-dimensional (2D) COSY experiment that...
604


