有效访问难以捉摸的1D13C NMR光谱通过高分辨率1H,13C-长距离相关性光谱学
Peyman Sakhaii1, Bojan Bohorc1, Uwe Schliedermann1
1NMR Laboratory of SANOFI, Global CMC Early Development, Synthetics Platform, Industrial Park Hoechst, Building G849, 65926 Frankfurt/Main, Germany.
Analytical chemistry
|March 7, 2024
概括
这项研究为天然产品引入了一种新的质子检测1D13CNMR方法. 它产生清晰的13C单片,改善信号噪声,减少代谢物分析的获取时间.
科学领域:
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
- 代谢学 代谢学 代谢学
- 自然产品化学 自然产品化学
背景情况:
- 质子检测的1D13CNMR对于分析天然产品和代谢产物至关重要.
- 传统方法通常需要宽带质子解,使光谱解释复杂化.
- 改善信号噪声比 (SINO) 和缩短采集时间仍然是关键挑战.
研究的目的:
- 开发一种以质子检测的1D13C核磁共振 (NMR) 方法,在没有宽带质子脱的情况下产生单子.
- 为了提高光谱质量和自然产品和代谢物表征的效率.
- 为直接C激发方法提供一个优质的替代方案.
主要方法:
- 使用恒时HMBC (CT-HMBC) 和传统的HSQC实验,具有高数字分辨率和纯相处理.
- 实施非均采样 (NUS) 和回声处理,用于具有狭窄C线形状的相敏感2D光谱.
- 结合CT-HMBC和HSQC的C投影以获得最终的1D光谱,抑制合并优化放松.
主要成果:
- 该方法通过去除H多重结构,为所有碳类型生成13个C单体.
- 观察到13C信号与噪声比 (SINO) 的显著增加,特别是在四级碳中 (增强至6-12倍).
- 不统一的采样大大减少了总采集时间,而回声处理则清除了光谱.
结论:
- 开发的质子检测1D13C核磁共振技术为天然产品和代谢物提供了增强的SINO和光谱清晰度.
- CT-HMBC和HSQC投影的正交组合将与合延迟和T2放松相关的风险降到最低.
- 这种方法在代谢学和自然产品化学中为结构阐明提供了强大而高效的方法.
相关概念视频
2D NMR: Overview of Heteronuclear Correlation Techniques
179
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
179
2D NMR: Overview of Homonuclear Correlation Techniques
197
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...
197
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
707
Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
707
2D NMR: Homonuclear Correlation Spectroscopy (COSY)
1.1K
Homonuclear correlation spectroscopy, or COSY, is a 2-dimensional NMR technique that provides information about coupled protons. Typically, the geminal and vicinal coupling are observed. For example, consider the COSY spectrum of ethyl acetate, where its 1D proton NMR spectrum is plotted along the vertical and horizontal axes with their corresponding chemical shift scale. Three spots on the diagonal corresponding to the three peaks in the 1D proton spectrum are called diagonal peaks. The COSY...
1.1K
¹³C NMR: ¹H–¹³C Decoupling
1.1K
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...
1.1K
¹H NMR: Long-Range Coupling
1.7K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
1.7K


