The degradation, antioxidant and antimutagenic activity of the mucilage polysaccharide from Dioscorea opposita

• Polysaccharide from Dioscorea opposita was degraded with the oxidation method.
• The antioxidant and antimutagenic activity of all the samples were investigated.
• The degraded sample with lower molecular weight possessed higher activities.

The mucilage polysaccharide was extracted from Dioscorea opposita in cold water and then degraded in two reagents hydrogen peroxide and ascorbic acid. Three low-molecular-weight-samples were prepared, and their antioxidant and antimutagenic activity were investigated. Chemical composition analysis indicated that the degradation action was in a concentration dependent manner. Total sugars content of three degraded samples were significantly higher than raw sample. The uronic acid content in the degraded sample LP3 was significantly higher than other samples. LP3 processed the higher scavenging effect on hydroxyl and superoxide radicals than other two degraded samples because of its lower molecular weight and more uronic acid. LP3 processed the excellent antimutagenic activity and higher anti-lipid peroxidation in garlic roots. There maybe a certain relationship between the two activities. The present results indicated this mucilage could be a potential candidate of the natural antimutagen.