脯氨酸类N-酰胺衍生物的核磁共振研究

脯氨酸类衍生物结构独特，鲜有报道利用核磁共振（nuclear magnetic resonance，NMR）技术对氨基酸的手性进行鉴别.利用多种NMR技术:1H NMR、1H-1H同核位移相关谱（1H-1H COSY）、1H-1H质子全相关谱（1H-1H TOCSY）、1H-1H核Overhauser效应谱（1H-1H NOESY）、13C NMR、无畸变的极化转移增强法（DEPT135°）、1H-13C检出1H的异核单量子相干（1H-13C HSQC）和1H-13C检出1H的异核多键相关（1H-13C HMBC），对脯氨酸类N-酰胺衍生物两种构象异构体的1H和13C NMR进行了全归属，确定了室温下在二甲基亚砜（DMSO）中L型和D型的顺反异构体以相同的比例同时存在.

An Nuclear Magnetic Resonance Study of Proline N-Amide Derivative

Proline derivatives have unique structures, and few reports have been published on the chiral identification of amino acids by nuclear magnetic resonance (NMR). The structures of two proline N-amide conformation isomers were analyzed in detail using ¹H NMR, ¹H-¹H correlated spectroscopy(¹H-¹H COSY), ¹H-¹H total correlation spectroscopy(¹H-¹H TOCSY), ¹H-¹H nuclear overhauser effect spectroscopy(¹H-¹H NOESY), ¹³C NMR, distortionless enhancement by polarization transfer(DEPT135°), ¹H-¹³C ¹H detected heteronuclear single quantum coherence(¹H-¹³C HSQC) and ¹H-¹³C ¹H detected heteronuclear multiple-bond correlation(¹H-¹³C HMBC) techniques, and the positions of ¹H and ¹³C NMR peaks of the derivatives were assigned. The co-existence of L- and D-type cis-trans isomers in dimethylsulfoxide (DMSO) at room temperature were determined.