刺梨多糖的理化性质、体外抗氧化和α-葡萄糖苷酶抑制活性

Physicochemical Characterization, in vitro Antioxidant and α-Glucosidase Inhibitory Activity of Polysaccharides from Rosa sterilis Fruit

摘要:

采用热水提取和分级醇沉技术，从无籽刺梨中制备得到两种主要多糖组分，命名为RSPs-40和RSPs-60，对其化学组成、理化性质、体外抗氧化活性和α-葡萄糖苷酶抑制活性进行了研究。结果表明，RSPs-40和RSPs-60的提取率分别为2.62%和1.81%，总糖含量分别为42.5%±0.91%和45.90%±0.37%，蛋白质含量均为2.89%。高效凝胶渗透色谱（HPGPC）分析表明RSPs-40和RSPs-60的分子量大小分别为 228.298 ku和124.144 ku。单糖组成分析表明RSPs-40主要由阿拉伯糖、半乳糖、葡萄糖、果糖和半乳糖醛酸组成，摩尔比为0.24:0.37:3.22:0.27:1.44，而RSPs-60主要由阿拉伯糖、半乳糖、葡萄糖和半乳糖醛酸组成，摩尔比为1.58:2.06:2.37:1.69。体外抗氧化实验结果表明RSPs-40和RSPs-60较好的DPPH自由基清除活性和ABTS自由基清除活性；体外降血糖实验结果表明RSPs-40和RSPs-60表现出较强的α-葡萄糖苷酶抑制活性，二者均优于阿卡波糖。RSPs-60抗氧化和α-葡萄糖苷酶抑制活性优于RSPs-40。这些结果表明无籽刺梨多糖可发一种有前途的抗氧化和降血糖膳食补充剂，应用于食品和医药领域。

Abstract:

Two main polysaccharide fractions (RSPs-40 and RSPs-60) were isolated from Rosa sterilis fruit by hot water extraction and fractional alcohol precipitation, respectively. The physicochemical characteristic, antioxidant and α-glucosidase inhibition activity of RSPs-40 and RSPs-60 were investigated. The results showed that the extraction yields of RSPs-40 and RSPs-60 were 2.62% and 1.81%, respectively. The total sugar contents of RSPs-40 and RSPs-60 were 42.5%±0.91% and 45.90%±0.37%, respectively. Protein contents were all 2.89%. The average molecular weights of RSPs-40 and RSPs-60 were 228.298 ku and 124.144 ku, respectively. Monosaccharide composition analysis showed that RSPs-40 mainly consisted of arabinose, galactose, glucose, fructose, and galacturonic acid in a molar ratio of 0.24:0.37:3.22:0.27:1.44, while RSPs-60 was mainly composed of arabinose, galactose, glucose, and galacturonic acid in a molar ratio of 1.58:2.06:2.37:1.69. The results of in vitro antioxidant assays showed that RSPs-40 and RSPs-60 exhibited good DPPH and ABTS free radical scavenging activity. The results of in vitro hypoglycemic assays showed that RSPs-40 and RSPs-60 exhibited stronger α-glucosidase inhibitory activity than acarbose. The antioxidant and α-glucosidase inhibitory activities of RSPs-60 were better than those of RSPs-40. Overall, these results suggested that the polysaccharides from R. sterilis fruit could be explored as a promising antioxidant and hypoglycemic dietary supplement.