478. Studies of Aspergillus niger. Part VI. The separation and structures of oligosaccharides from nigeran
478. Studies of Aspergillus niger. Part VI. The separation and structures of oligosaccharides from nigeran
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478. 黑曲霉的研究。
DOI：
10.1039/jr9570002448
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发表时间：
1957
期刊：
影响因子：
--
通讯作者：
M. Stacey
中科院分区：
文献类型：
--
作者：
S. A. Barker;E. J. Bourne;D. M. O'Mant;M. Stacey
三-O-甲基-D-葡萄糖被证明具有未封端的Co，因为它能够在室温下在甲醇氯化氢中形成呋喃甲酯。当三-0-甲基-葡萄糖还原成相应的山梨醇衍生物时，产物消耗了近1mol。产生高碘酸盐，但不产生醛和可忽略量的甲酸。预期以这种方式表现的两种三甲基山梨糖醇衍生物具有 Cm 和 C（且不含 2: 3: 6-和 2: 5: 衍生物。然而，由于三-0-甲基糖在色谱上可与 2: 3: Merivative 区分开，因此它一定是 2: 5: 6-三-0-甲基-D-葡萄糖。因此，有充分的证据表明级分 (I) 和 (11) 主要分别是 3-OaD-glUCOpyranOSyl-D-glUCOSe 的 α-([a],,+ 40') 和 α-甲基呋喃糖苷 ([a] D+ 12S0)。 通过在木炭柱上优先形成呋喃糖苷和分馏，对三糖异构体 T 和 T 进行空间分离，得到色谱纯的 T，以及含有不同量 (7.3-28~ 0) T, 的 T, contaminattA 的甲基呋喃糖苷的级分。 呋喃糖苷很容易从 T, bg 分级中分离出来。
The tri-O-methyl-D-glucose was shown to have Co unblocked because of its ability to undergo methyl-furanaide formation in methanolic hydrogen chlofide at room temperature. When the tri-0-methyl-&glucose was reduced to the corresponding sorbitol derivative, the product consumed practically 1 mol. of periodate but produced no faimddehyde and a negligible amount of formic acid. The ody two tri4hmethylsotbitol derivatives which would be expected to behave in this way and have Cm and C (& free were the 2: 3: 6-and the 2: 5: &derivative. Since however the tri-0-methyl sugar was distinguishable from the 2: 3: Merivative chromatographically, it must have been 2: 5: 6-tri-0-methyl-D-glucose. Ample evidence is therefore available to show that fractions (I) and (11) are predominautly the@-([a],,+ 40') and the a-methyl furanoside ([a] D+ 12S0), respectively, of 3-OaD-glUCOpyranOSyl-D-glUCOSe.Spatation of the trisaccharide isomers, T, and T,, effected by preferential furamside formation and fractionation on a charcoal column, gave chromatographically pure T, together with fractions containing the methyl furanosides of T, contaminattA with varying amounts (7.3-28~ 0) of T,. The furanosides were easily freed from the T, bg fractionation