Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-980 Curitiba, PR, Brazil.
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-980 Curitiba, PR, Brazil.
Carbohydr Polym. 2015 May 5;121:224-30. doi: 10.1016/j.carbpol.2014.12.034. Epub 2014 Dec 31.
A structural characterization of polysaccharides obtained from edible tropical fruit named starfruit (Averrhoa carambola L.) was carried out. After fractionation by freeze-thaw and Fehling precipitation, a pectic polysaccharide was obtained. It was composed of rhamnose, arabinose, galactose and uronic acid in the 5.0:72.5:12.1:10.4 molar ratios, respectively. A combination of monosaccharide, GPC, methylation and NMR analysis and enzymatic hydrolysis with endo-β-(1→4)-D-galactanase showed the presence of a rhamnogalacturonan I to which a branched arabinan and a type I arabinogalactan are attached. The arabinan moiety was formed by (1→5)-linked α-L-Araf units in the backbone, branched only at O-3 by (1→2)- and (1→3)-linked α-L-Araf units, while the type I arabinogalactan was formed by (1→4)- and (1→4,6)-linked β-D-Galp units in the backbone with (1→5)-, (1→3,5)- and (1→3)-linked α-L-Araf units as side chains.
对一种名为杨桃（Averrhoa carambola L.）的可食用热带水果中提取的多糖进行了结构表征。经反复冻融和费林沉淀分级后，得到一种果胶多糖。它由鼠李糖、阿拉伯糖、半乳糖和糖醛酸以摩尔比 5.0:72.5:12.1:10.4 组成。单糖、GPC、甲基化和 NMR 分析以及用内切-β-（1→4）-D-半乳糖苷酶的酶解组合表明，存在一种鼠李半乳糖醛酸聚糖 I，其上连接有分支阿拉伯聚糖和 I 型阿拉伯半乳聚糖。阿拉伯聚糖部分由主链上的（1→5）连接的α-L-Araf 单元组成，仅在 O-3 处由（1→2）和（1→3）连接的α-L-Araf 单元分支，而 I 型阿拉伯半乳聚糖由主链上的（1→4）和（1→4,6）连接的β-D-Galp 单元以及侧链上的（1→5）、（1→3,5）和（1→3）连接的α-L-Araf 单元组成。
