石榴皮多酚提取物及纯化物对α-葡萄糖苷酶的抑制作用研究

采用紫外分光光度法研究了石榴皮多酚提取物及其2种纯化物(P-1和P-2)对α-葡萄糖苷酶体外抑制作用以及纯化物对该酶的抑制作用类型.结果显示,石榴皮多酚提取物和纯化物对α-葡萄糖苷酶活性均表现出较强的抑制作用,且其作用大小与浓度呈明显的剂量-效应关系；3种多酚样品中,纯化物P-2的抑酶活性最强,纯化物P-1次之,提取物最弱,它们对α-葡萄糖苷酶的半数抑制浓度(IC50,mg/mL)分别为0.045、0.185和0.278.石榴皮多酚纯化物P-2对α-葡萄糖苷酶抑制作用类型为反竞争性抑制；浓度为0.01 mg/mL时该纯化物对α-葡萄糖苷酶的抑制常数Ki为1.22 μg/mL.

Inhibitory Effect of Polyphenol Extract from Pomegranate Peel and Its Purified Fractions on α-glucosidase Activity

This paper studied the inhibitory effect of a polyphenol extract from pomegranate peel and its two purified fractions(P-1 and P-2) on the activity of α-glucosidase by applying UV spectrophotometry.In addition,the inhibition type of one purified fraction was determined.The extract and the purified fractions showed a dose-dependent inhibitory effect on α-glucosidase activity,of which P-2 demonstrated the strongest inhibition followed by P-1 and the extract,their 50% inhibition concentrations(mg/mL) on the enzyme being 0.045,0.185 and 0.278,respectively.The purified fraction P-2 exhibited an anti-competitive inhibitory effect on α-glucosidase and its inhibition constant was 1.22 μg/mL at 0.01 mg/mL.