分析化学2024，Vol.52Issue(6)：866-875,10.DOI:10.19756/j.issn.0253-3820.231333
N-月桂酰基-L-丙氨酸分子组装结构的固体核磁共振研究
Insight of N-Lauroyl-L-alanine Molecular Assembly Using Solid-State Nuclear Magnetic Resonance Technique
摘要
Abstract
Amino acid surfactants (AAS) have excellent properties such as low toxicity,antibacterial,mildness,and corrosion resistance. In recent years,they have been widely applied in the field of daily chemicals,food and pharmaceutical industry. It is pointed out that the structure at molecular level largely affects the physical and chemical properties of AAS materials. In this work,the structures of solid-state N-lauroyl-L-alanine (NLLA) including intermolecular interactions,molecular local dynamics and molecular assembly were investigated by a variety of solid-state nuclear magnetic resonance (SSNMR) techniques. Based on 2D 1H-1H double quantum-single quantum (2D 1H-1H DQ-SQ),1H-1H DQ sideband pattern and molecular simulation,it was found that there was a stable intermolecular hydrogen bond formed between the carboxyl units of two NLLA molecules. Combined with the study of 2D frequency switched Lee—Goldberg heteronuclear correlation (2D 13C-1H FSLG-HETCOR) and 13C T1,another type of hydrogen bond was probed,which existed between amide units of neighboring molecules. In addition,the conformation of alkyl chain ends was investigated. According to 1D 13C{1H}cross polarization/magic angle spinning (CP/MAS) and 2D 13C-1H FSLG-HETCOR spectra,it was revealed that the alkyl-chain ends had both gauche and trans conformations. Moreover,the trans conformation showed two distinct 13C chemical shifts,originated from two NLLA molecular assembly forms. Accordingly,two NLLA molecular assembly structures were suggested which were transoid form and cisoid form. This work provided a SSNMR investigation strategy for characterizing the molecular local structure and dynamics of AAS materials,which helped task of researching and developing materials with improved chemical and physical properties.关键词
固体核磁共振/氨基酸表面活性剂/N-月桂酰基-L-丙氨酸/氢键/组装结构Key words
Solid-state nuclear magnetic resonance/Amino acid-based surfactants/N-Lauroyl-L-alanine/Hydrogen bond/Assembly引用本文复制引用
裘子慧,徐凌云,陈伊健,董洪春,舒婕,姚志刚..N-月桂酰基-L-丙氨酸分子组装结构的固体核磁共振研究[J].分析化学,2024,52(6):866-875,10.基金项目
江苏省大型科学仪器开放共享自主研究课题项目(No.TC2021A027)资助.Supported by the Independent Research Project of Open Sharing of Large Scientific Instruments in Jiangsu Province,China(No.TC2021A027). （No.TC2021A027）
