Abstract：
Xylooligosaccharides (XOs) have shown high potential as prebiotics with nutritional and health benefits. In this work, XOs were obtained from highly purified, carboxy-reduced glucuronoarabinoxylans by treatment with Driselase®. The mixtures were fractionated, and the structures were elucidated by methylation analysis and NMR spectroscopy. Antioxidant activity was determined by the methods of DPPH and β-carotene/linoleic acid. It was found that the most active oligosaccharides (P3 and G3) comprised 4 or 5 xylose units, plus two arabinoses and one 4-O-methylglucose as side chains, their sequence of units was determined. The optimal concentration for their use as antioxidants was 2 mg/mL. The synthetic antioxidant butylated hydroxytoluene (BHT, 0.2 mg/mL) showed a percentage of inhibition 15% higher than P3. Although its concentration was ∼10 times higher, P3 is non-toxic, and could have great advantages as food additive. These results show that pure XOs exert significant antioxidant activity, only due to their carbohydrate nature.
摘要：
低聚木糖(XOs)已显示出作为具有营养和健康益处的益生元的高潜力。在这项工作中,XO是从高度纯化的，用Driselase®处理的羧基还原的葡糖醛酸阿拉伯木聚糖。将混合物分馏,并通过甲基化分析和NMR光谱阐明了结构。通过DPPH和β-胡萝卜素/亚油酸的方法测定抗氧化活性。发现最活跃的寡糖（P3和G3）包含4或5个木糖单元，加上两个阿拉伯糖和一个4-O-甲基葡萄糖作为侧链，他们的单位序列被确定。它们用作抗氧化剂的最佳浓度为2mg/mL。合成抗氧化剂丁基化羟基甲苯(BHT,0.2mg/mL）显示比P3高15%的抑制百分比。尽管它的浓度高出约10倍，P3是无毒的，作为食品添加剂可能有很大的优势。这些结果表明，纯XOs发挥显著的抗氧化活性，只是因为它们的碳水化合物性质。
