五倍子中α-淀粉酶抑制因子的研究

采用甲醇粗提、索氏抽提及pH值梯度提取和聚酰胺柱层析等分离纯化法及酶反应动力学跟踪的方法对五倍子中的α-淀粉酶抑制因子进行系统研究。结果表明：乙醚、乙酸乙酯、丙酮-水(体积比1:1)、甲醇、石油醚组分和甲醇粗提物对α-淀粉酶的抑制率依次为：91.04%、90.38%、80.09%、66.48%、34.14%和23.96%。其中石油醚组分中的α-淀粉酶抑制因子是月桂酸、肉豆蔻酸和棕榈酸，其抑制率分别为34.34%、31.71%和31.01%，而乙醚组分中的抑制因子是鞣酸及没食子酸，其抑制率分别为66.7% 和21.3%。丙酮-水组分中的抑制因子较为复杂，经初步纯化和气质联用得知其为脂肪醇类并部分甲酯化。

Alpha-Amylase Inhibitors in Galla Chinensis

In order to separate the inhibitory factors of α-amylase in Galla Chinensis, crude methanol extract of Galla Chinensis was fractionated by sequential Soxhlet extraction with petroleum ether, ethyl ether, ethyl acetate and methanol. Meanwhile, the residue left after methanol extraction was extracted with acetone-water (1:1, V/V) and the extract obtained was further separated by pH gradient extraction, polyamide column chromatography and Seaphadex LH-20, respectively. The inhibitory activity of all samples against α-amylase was determined. The results showed that the inhibitory rates of ethyl ether fraction, ethyl acetate fraction, acetone-water extract, methanol faction (obtained from secondary extraction by Soxhlet method), petroleum ether fraction and crude methanol extract were 91.04%, 90.38%, 80.09%, 66.48%, 34.14% and 23.96%, respectively. The α-amylase inhibitors in petroleum ether fraction were lauric acid, myristic acid and palmitic acid with corresponding inhibitory rates of 34.34%, 31.71% and 31.01%, respectively. Tannic acid and gallic acid were the α-amylase inhibitors in ethyl ether fraction, with corresponding inhibitory rates of 66.7% and 21.3%, respectively. The α-amylase inhibitor composition in acetone-water extract was complicated and consisted of partially methyl-esterified fatty alcohols according to preliminary purification and GC-MS analysis.