紫甘薯茎叶中绿原酸及异绿原酸对α-葡萄糖苷酶的抑制作用  

Inhibitory Effects of Chlorogenic Acid and Isochlorogenic Acid from Purple Sweet Potato Leaves on α-glucosidase

作　　者：刘雪辉[1] 李觅路[1] 谭斌 陈惠衡[1] 陆英[1,2] 

机构地区：[1]湖南农业大学园艺园林学院,湖南长沙410128 [2]国家植物功能成分利用工程技术研究中心,湖南长沙410128

出　　处：《现代食品科技》2014年第3期103-107,共5页Modern Food Science and Technology

基　　金：湖南省科技厅资助(2012NK3088)

摘　　要：本实验通过高速逆流色谱从紫甘薯茎叶中制备分离得到绿原酸(1)、4,5-O-咖啡酰基奎宁酸(2,异绿原酸C)、3,5-O-咖啡酰基奎宁酸(3,异绿原酸A)及3,4-O-咖啡酰基奎宁酸(4,异绿原酸B)等四个高纯度天然化合物,并以4-硝基酚-α-D-吡喃葡萄糖苷(PNPG)为底物分别测定了四个化合物及紫甘薯茎叶提取物对α-葡萄糖苷酶的抑制作用。结果显示上述4个化合物及紫甘薯茎叶粗提物抑制α-葡萄糖苷酶的IC50值分别为:7.556μg/mL、1.419μg/mL、0.209μg/mL、9.339μg/mL和5.371μg/mL,均远远低于阳性对照阿卡波糖的IC50(355.4μg/mL),而进一步的酶抑制反应动力学分析结果显示化合物及提取物对α-葡萄糖苷酶表现为竞争性抑制类型。试验表明紫甘薯茎叶提取物具有显著的α-葡萄糖苷酶抑制作用,为甘薯茎叶资源作为降糖保健品或药品开发提供理论依据。Chlorogenic acid （1）, 4,5-O-caffeoylquinic acid （2）, 3,5-O-caffeoylquinic acid （3） and 3,4-O-eaffeoylquinic acid （4） were isolated and prepared from purple sweet potato leaves by high speed counter-current chromatography （HSCCC）. Then the inhibitory effect of these compounds and crude extract of sweet potato leaves on α-glucosidase were examined by using PNPG as substrate. The results indicated that four compounds and crude extract of sweet potato leaves exhibited certain inhibitory effects on α-glucosidase, with IC50 value of 7.556 ~μg/mL, 1.419 μg/mL, 0.209 μg/mL, 9.339 μg/mL and 5.371 μg/mL, respectively, which were far less than the positive control acarbose （ICso 355.4 p.g/mL）. In addition, the kinetic analysis showed the inhibitory effects of the four compounds on α-glucosidase were competitive, and the Ki were 27.18 μg/mL, 2.06 μg/mL, 8.42 μg/mL and 19.58 μg/mL, respectively. Therefore, sweet potato leaf extract has significant α-glucosidase inhibition, and could provide a theoretical basis for sweet potato leaves as a resource of hypoglycemic drug development or health care.

关 键 词：紫甘薯茎叶 绿原酸 异绿原酸 Α-葡萄糖苷酶 抑制作用 

分 类 号：R587.1[医药卫生—内分泌]