Yu R K, Koerner T A, Ando S, Yohe H C, Prestegard J H
J Biochem. 1985 Nov;98(5):1367-73. doi: 10.1093/oxfordjournals.jbchem.a135404.
Ganglioside GM3 lactone (1) was prepared in 95% yield from the parent ganglioside by incubation at 25 degrees C for 4 days in glacial acetic acid. Inspection of the 500 MHz proton NMR spectra of 1 and its precursor in dimethylsulfoxide-d6-deuterium oxide at 30 degrees C revealed a large deshielding (+1.42 ppm) of the H-2 resonance of the galactosyl residue. This suggests that 1 must be the lactone formed by esterification of the sialic acid carboxyl group with the C-2 hydroxyl of the galactosyl residue. Consideration of all the NMR data leads to a specific structure proposal in which 1 has a highly rigid structure. Interesting features of the structure include a hydrophobic inner surface and a semicircular outer edge of seven-oxygen atoms, which may have physiological importance.
神经节苷脂GM3内酯（1）通过在25℃下于冰醋酸中孵育4天，从母体神经节苷脂以95%的产率制备得到。在30℃下对1及其前体在二甲基亚砜 - d6 - 重水中的500 MHz质子核磁共振谱进行检查，发现半乳糖基残基的H - 2共振有很大的去屏蔽作用（+1.42 ppm）。这表明1必定是由唾液酸羧基与半乳糖基残基的C - 2羟基酯化形成的内酯。对所有核磁共振数据的考虑得出了一个特定的结构提议，其中1具有高度刚性的结构。该结构的有趣特征包括一个疏水的内表面和一个由七个氧原子组成的半圆形外边缘，这可能具有生理重要性。
