Molecular organization and motions of crystalline monoacylglycerols and diacylglycerols: a C-13 MASNMR study.
Molecular organization and motions of crystalline monoacylglycerols and diacylglycerols: a C-13 MASNMR study.
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结晶单酰基甘油和二酰基甘油的分子组织和运动：C-13 MASNMR 研究。
DOI：
10.1016/s0006-3495(95)80311-5
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Hamilton,JA
中科院分区：
文献类型：
--
作者：
Guo,W;Hamilton,JA
用天然丰度C-13核磁共振魔角自旋（MASNMR）研究了6种饱和酰基甘油（1-肉豆蔻酰-sn-甘油、1-棕榈酰-sn-甘油、1，2-二肉豆蔻酰-sn-甘油、1，2-二棕榈酰-sn-甘油、1，2-二棕榈酰-rac-甘油和1，3-二肉豆蔻酰甘油）的各种多晶型（亚α、α、β '）。C-13 MASNMR不需要单晶，可以观察相对无序的晶体，这比晶体衍射方法有明显的优势。得到很好的解决光谱为每个酰基甘油，和相应的碳的化学位移是不同的每个晶相和各向同性的液相;此外，在单酰基甘油的情况下，在相同的晶体结构中的对称非等效分子给不同的C-13共振相同的碳。对应于每个多晶相的C-13化学位移被解释在分子内键距，分子间相互作用（如氢键），和分子运动的差异。甘油主链和酰基链的迁移率由C-13线宽和C-H偶极弛豫速率评估。从慢自旋MAS光谱确定每个酰基甘油的羰基的化学位移各向异性（ES）（Δ Σ），并根据羰基碳的构象和/或运动变化进行了讨论。
Six saturated acylglycerols (1-myristoyl-sn-glycerol, 1-palmitoyl-sn-glycerol, 1,2-dimyristoyl-sn-glycerol, 1,2-dipalmitoyl-sn-glycerol, 1,2-dipalmitoyl-rac-glycerol, and 1,3-dimyristoylglycerol) were studied in their various polymorphic forms (sub-alpha, alpha, beta') by natural abundance C-13 nuclear magnetic resonance (NMR) with magic angle spinning (MASNMR). C-13 MASNMR does not require single crystals and can observe relatively disordered crystals, distinct advantages over crystallographic diffraction methods. Well resolved spectra were obtained for each acylglycerol, and the chemical shifts of corresponding carbons were different for each crystalline phase and the isotropic liquid phase; moreover, in the case of monoacylglycerols, the symmetrically nonequivalent molecules in the same crystalline structure gave distinct C-13 resonances for the same carbon. The C-13 chemical shifts corresponding to each polymorphic phase were interpreted in terms of differences in intramolecular bond distances, intermolecular interactions (such as H bonding), and molecular motions. Mobilities of the glycerol backbone and acyl chains were assessed by the C-13 linewidths and the C-H dipolar relaxation rates. The chemical shift anisotropy(ies) (delta sigma) of the carbonyl group(s) of each acylglycerol was determined from slow-spinning MAS spectra, and was discussed in terms of the conformational and/or motional changes for the carbonyl carbon(s).