Ovchinnikova Olga G, Moryl Magdalena, Shashkov Alexander S, Chizhov Alexander O, Arbatsky Nikolay P, Shpirt Anna M, Rozalski Antoni, Knirel Yuriy A
N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
Department of Immunobiology of Bacteria, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, PL 90-237 Lodz, Poland.
Carbohydr Res. 2015 Jan 12;401:11-5. doi: 10.1016/j.carres.2014.10.016. Epub 2014 Oct 27.
The O-polysaccharide was obtained by degradation of the lipopolysaccharide of Providencia alcalifaciens O2 under mild acidic conditions followed by GPC. The polysaccharide was found to contain two unusual components: 3,6-dideoxy-L-arabino-hexose (ascarylose, Asc) and 2-(L-alanyl)amino-2-deoxy-D-glucose (GlcNAla). Ascarylose was partially split off during lipopolysaccharide degradation and could be eliminated completely by selective acid hydrolysis, which also partially cleaved the β-GAlNAc-(1 → 6) linkage. The following structure of the branched pentasaccharide repeating unit was established by (1)H and (13)C NMR spectroscopy of the O-polysaccharide and O-deacetylated polysaccharide, as well as products of partial acid hydrolysis: α-Ascp-(1 → 4)-α-D-GlcpA-(1 → 4) → 6)-β-D-GlcpNAla-(1 → 4)-β-D-GlpA-(1 → 3)-β-D-GalpNAc-(1 → ~60% OAc--3).
通过在温和酸性条件下对产碱普罗威登斯菌O2的脂多糖进行降解，随后进行凝胶渗透色谱（GPC），获得了O-多糖。发现该多糖含有两种不寻常的成分：3,6-二脱氧-L-阿拉伯己糖（阿糖胺，Asc）和2-（L-丙氨酰）氨基-2-脱氧-D-葡萄糖（GlcNAla）。阿糖胺在脂多糖降解过程中部分脱落，可通过选择性酸水解完全去除，该水解还部分切断了β-GAlNAc-(1→6)键。通过对O-多糖、O-脱乙酰化多糖以及部分酸水解产物进行（1）H和（13）C核磁共振光谱，确定了以下分支五糖重复单元的结构：α-Ascp-(1→4)-α-D-GlcpA-(1→4)→6)-β-D-GlcpNAla-(1→4)-β-D-GlpA-(1→3)-β-D-GalpNAc-(1→~60% OAc--3) 。
