Hunter B K, Mowbray S L, Walton D J
Biochemistry. 1979 Oct 16;18(21):4458-65. doi: 10.1021/bi00588a002.
In order to study the structure of the methylglucose-containing polysaccharide (MGP) of Mycobacterium smegmatis by NMR spectroscopy, we have prepared the model compound O-alpha-D-glucopyranosyl-(1 leads to 2)-D-glyceric acid. This compound, which represents the aglycon-containing terminus of MGP, was made from leucorse [O-alpha-D-glucopyranosyl-(1 leads to 5)-D-fructopyranose] by successive treatment with sodium borohydride, lead tetraacetate, and hypobromite. The structure of O-alpha-D-glucopyranosy.-(1 leads to 2)-D-glyceric acid was confirmed by chemical and enzymic methods. 13C and 1H NMR spectra of this compound, together with spectra of several disaccharides, were obtained for future reference in the polysaccharide study. The nine resonances in the 13C spectrum were assigned by comparison with the spectrum of methyl alpha-D-glucopyranoside. Analysis of the 1H NMR spectrum showed that the two methylene protons on C-3 of the glycerate moiety were less equivalent in the sodium salt than in the acid. This may be attributable to hydrogen bonding between the carboxylate and the hydrogen atom of the glycerate 3-hydroxyl group.
为了通过核磁共振光谱研究耻垢分枝杆菌含甲基葡萄糖的多糖（MGP）的结构，我们制备了模型化合物O-α-D-吡喃葡萄糖基-(1→2)-D-甘油酸。该化合物代表MGP含苷元的末端，由来苏糖[O-α-D-吡喃葡萄糖基-(1→5)-D-呋喃果糖]经硼氢化钠、四乙酸铅和次溴酸盐连续处理制得。通过化学和酶法确定了O-α-D-吡喃葡萄糖基-(1→2)-D-甘油酸的结构。获得了该化合物的13C和1H核磁共振光谱以及几种二糖的光谱，以供多糖研究时参考。通过与α-D-吡喃葡萄糖苷甲酯的光谱比较，确定了13C光谱中的九个共振峰。对1H核磁共振光谱的分析表明，甘油酸部分C-3上的两个亚甲基质子在钠盐中的等效性低于在酸中的等效性。这可能归因于羧酸盐与甘油酸3-羟基氢原子之间的氢键作用。
