Abstract：
Profiling of pectic arabinans and galactans by analysis of the released oligosaccharides after backbone cleavage provides information on the complexity of the polymer structure. In plants of the family Amaranthaceae, arabinan and galactan substitution with ferulates extends the polysaccharide complexity, changing its chemical properties. Knowledge of the ferulate environment is crucial to understand structure-function-relationships of feruloylated pectins. Here, we present an approach to separate enzymatically generated feruloylated and non-feruloylated arabino- and galactooligosaccharides, followed by deesterification and semiquantitative analysis by HPAEC-PAD using previously reported relative response factors. Application of this approach to sugar beet pectins and insoluble and soluble dietary fiber preparations of amaranth and quinoa suggests that ferulates are preferably incorporated into more complex structures, as nicely demonstrated for feruloylated galactans. Also, ferulate substitution appears to negatively affect enzymatic cleavage by using endo-enzymes. As a consequence, we were able to tentatively identify new feruloylated tri- and tetrasaccharides of galactans isolated from sugar beet pectins.
摘要：
通过分析主链裂解后释放的寡糖来分析果胶阿拉伯聚糖和半乳聚糖提供了有关聚合物结构复杂性的信息。在牡丹科植物中，用阿魏酸酯取代阿拉伯聚糖和半乳聚糖扩展了多糖的复杂性，改变其化学性质了解阿魏酸盐环境对于了解阿魏酸盐果胶的结构-功能-关系至关重要。这里,我们提出了一种分离酶促产生的阿魏酸化和非阿魏酸化阿拉伯寡糖和低聚半乳糖的方法，然后使用先前报道的相对响应因子通过HPAEC-PAD进行脱酯化和半定量分析。将此方法应用于甜菜果胶以及a菜和藜麦的不溶性和可溶性膳食纤维制剂表明，优选将阿魏酸盐掺入更复杂的结构中，正如阿魏酸化半乳聚糖所证明的那样。此外，通过使用内切酶，阿魏酸酯取代似乎会对酶促切割产生负面影响。因此,我们能够初步鉴定从甜菜果胶中分离出的半乳聚糖的新阿魏酸化三糖和四糖。
