Abstract:
Two-dimensional (2D) J-resolved spectroscopy provides valuable information on J-coupling constants for molecular structure analysis by resolving one-dimensional (1D) spectra. However, it is challenging to decipher the J-coupling connectivity in 2D J-resolved spectra because the J-coupling connectivity cannot be directly provided. In addition, 2D homonuclear correlation spectroscopy (COSY) can directly elucidate molecular structures by tracking the J-coupling connectivity between protons. However, this method is limited by the problem of spectral peak crowding and is only suitable for simple sample systems. To fully understand the intuitive coupling relationship and coupling constant information, we propose a three-dimensional (3D) COSY method called CTCOSY-JRES (Constant-Time COrrelation SpectroscopY and J-REsolved Spectroscopy) in this paper. By combining the J-resolved spectrum with the constant-time COSY technique, a doubly decoupled COSY spectrum can be provided while preserving the J-coupling constant along an additional dimension, ensuring high-resolution analysis of J-coupling connectivity and J-coupling information. Moreover, compression sensing and fold-over correction techniques are introduced to accelerate experimental acquisition. The CTCOSY-JRES method has been successfully validated in a variety of sample systems, including industrial, agricultural, and biopharmaceutical samples, revealing complex coupling interactions and providing deeper insights into the resolution of molecular structures.
摘要:
二维(2D)J分辨光谱通过解析一维(1D)光谱为分子结构分析提供了有关J耦合常数的有价值的信息。然而,在2DJ分辨光谱中破译J耦合连通性是具有挑战性的,因为不能直接提供J耦合连通性。此外,2D同核相关光谱(COSY)可以通过跟踪质子之间的J耦合连接来直接阐明分子结构。然而,这种方法受到光谱峰拥挤问题的限制,仅适用于简单的样品系统。为了充分了解直观的耦合关系和耦合常数信息,本文提出了一种三维(3D)COSY方法,称为CTCOSY-JRES(恒定时间相关性光谱和J-重溶光谱)。通过将J分辨光谱与恒定时间COSY技术相结合,可以提供双解耦的COSY谱,同时保持沿附加维度的J耦合常数,保证J耦合连通性和J耦合信息的高分辨率分析。此外,引入压缩感知和折叠校正技术来加速实验采集。CTCOSY-JRES方法已在各种示例系统中成功验证,包括工业,农业,和生物制药样品,揭示复杂的耦合相互作用,并为分子结构的分辨率提供更深入的见解。