β-葡萄糖苷酶水解对辽东楤木嫩芽皂苷理化性质的影响

Effect of hydrolyzing with β-glucosidase on the physical and chemical properties of aralosides

以实验室制备的本溪产辽东楤木嫩芽皂苷为试验材料,探索了β-葡萄糖苷酶酶解对辽东楤木嫩芽皂苷基本理化性质的影响。结果表明:经过β-葡萄糖苷酶酶解后辽东楤木嫩芽皂苷黏度明显减小,颜色变为浅黄色,溶解度增大,挥发程度提高,刺激气味变强烈,甜味降低。经过硅胶柱分离的样品组分的质量比例与齐墩果酸含量比例也发生变化,齐墩果酸含量由原来的33.5%升高至37.2%。随着皂苷溶液浓度的增大其清除羟基自由基与氧自由基的能力逐渐增强,β-葡萄糖苷酶酶解可显著提高皂苷自由基的清除效果。β-葡萄糖苷酶酶解后辽东楤木嫩芽总皂苷吸收峰明显减少,紫外吸收明显向低波长靠近,最大的吸收峰由299 nm降低到236 nm。红外图谱表明:酶解后增加了脂肪族伯胺、脂肪族仲醇、脂肪族羧酸、不饱和脂肪酸脂;经详细图谱检索,说明β-葡萄糖苷酶水解掉部分葡萄糖,裸露出了β-D-半乳糖、苯基葡萄糖苷、羧基与长的碳链。这说明β-葡萄糖苷酶水解掉部分单糖,使皂苷单体分子明显变小,单体数量减少,改变其物理化学特性,提高其清除自由基能力,这为提高辽东楤木嫩芽总皂苷活性提供参考。

The material was the aralosides extracted from Aralia elata （Miq） Seem which is planted in Benxi city Liaoning province. The main physical and chemical properties of the aralosides were analyzed after hydrolyzation with β- glucosidase in this study. The results indicated that the viscidity of the aralosides was decreased after hydrolyzation with β-glucosidase, and the color of the araloside was changed from brown to buff, the solubility was improved, the vol- atilization was boosted, the stimulating odor was stronger, and the sweet taste was reduced. The proportions of quantity and oleanolic acid content in the six fractions separated by silica gel column were changed and the content of oleanolic acid in the aralosides rose from 33.5% to 37. 2%. The capability of eliminating hydroxyl and superoxide anions free radical was positively related to aralosides concentration. The capability of eliminating free radical was improved obvi- ously after hydrolyzation by β-glucosidase. The figure of ultraviolet absorption indicated that the quantity of the absorb- ing peaks reduced obviously, the absorption band was close to the shorter wavelength, and the biggest absorbing peak was changed from 299 - 236nm after hydrolyzation by β-glucosidase. The figures of infrared absorption indicate that the functional groups such as aliphatic primary amines, secondary aliphatic alcohols, aliphatic carboxylic acids and unsatu- rated fatty acid appeared after hydrolyzation by β-glucosidase. The molecules of β-D galactose, phenyl glucoside, ben- zoic acid and long carbon chain emerged. These changes proved that the glucose molecule was released from the aralo- sides after hydrolyzation by the β-glucosidase, the molecules of the aralosides became smaller, the mount of monomers reduced, the main physical and chemical properties were changed , and the capability of eliminating free radical was im- proved obviously. All of these results gave a reference for the improvement of the physiological activities.