孙海红 薛鲁燕 孙永红 张瑞巧 王文娇 蔡葵 赵征宇

摘要 莼菜多糖具有抗肿瘤、降血糖、降血脂等多种生理活性。从莼菜（Brasenia schreberi）中提取胶质多糖，采用碱提和酶法预处理提取莼菜多糖，经过除蛋白、醇沉、透析得到多糖组分，并结合高效液相色谱（HPLC）、原子力显微镜（AFM）和扫描电镜（SEM）等现代仪器技术和物理化学方法对其进行单糖组分、纯度及分子量测定等分析。莼菜多糖的提取工艺为料液比1∶20（W/V），纤维素酶100 U/g、果胶酶100 U/g 、木瓜蛋白酶1 100 U/g，pH为5，预处理温度为50 ℃，时间3 h。再用0.02 mol/L NaOH溶液30 ℃加热3 h提取，得率为0315%。高效液相色谱法测得的莼菜多糖中单糖组成分为鼠李糖、葡萄糖醛酸、半乳糖、木糖、阿拉伯糖、岩藻糖，摩尔比约为1.0∶1.0∶6.8∶2.0∶0.3∶3.0，凝胶渗透色谱测得分子量2.44×106。部分酸水解后单糖组成表明莼菜多糖的中心链主要为葡萄糖醛酸和半乳糖，支链的边缘结构或末端残基结构为鼠李糖、半乳糖、岩藻糖和阿拉伯糖和木糖。通过原子力显微镜和扫描电镜观察可知莼菜多糖是呈网状交联的凝胶结构。

关键词 莼菜;多糖;理化性质;空间结构

中图分类号 S645.9文献标识码 A文章编号 0517-6611（2021）02-0158-04

doi：10.3969/j.issn.0517-6611.2021.02.043

开放科学（资源服务）标识码（OSID）：

Study on Extraction and Physicochemical Properties of Polysaccharide from Brassica schreberi

SUN Haihong， XUE Luyan， SUN Yonghong et al

（Qingdao Academy of Agricultural Sciences， Qingdao， Shandong 266100）

Abstract Polysaccharide from Brassica schreberi had antitumor， hypoglycemic， hypolipidemic and other physiological activities. In this paper， the extraction conditions of glycine from Brasenia schreberi were optimized. The physicochemical properties and spatial structure of the glycine were studied. The optimized extraction process was as follows： the ratio of material to liquid 1∶20 （W/V）， cellulase 100 U/g， pectinase 100 U/g， papain 1 100 U/g， pH 5， the pretreatment temperature 50 ℃， time 3 h. And then the product treated with 0.02 mol/L NaOH solution at 30 ℃ for 3 h.The yield of glycine was 0.315%. The monosaccharides was determined by high performance liquid chromatography （HPLC）. The glycine was composed of rhamnose， glucuronic acid， galactose， xylose， arabinose and fucose at the ratio of 1.0∶10∶6.8∶2.0∶0.3∶3.0. It had a molecular weight of 2.44×106. Partial acid hydrolysis revealed that the central chain of polysaccharide was mainly composed of glucuronic acid and galactose. Rhamnose， galactose， fucose， arabinose and xylose consisted the branches of the polysaccharide. Atomic force microscopy and scanning electron microscope showed that B. schreberi polysaccharides formed a chain structure with branch nodes. The chain structure crosslinked to form a network of fibrous structures.

Key words Brasenia schreberi;Polysaccharide;Physicochemical properties;Spatial structure

莼菜（Brasenia schreberi J.F.Gmel）系原始花被亞纲睡莲科（Nymphaeaceae）植物[1]，属多年生淡水水生草本植物，又名马蹄草、湖菜、水葵、露葵，生长于池塘、湖泊和沼泽中[2-3]。近年来，由于其在食用和药用上的突出价值，因而受到人们的普遍关注[4]，我国很早就将莼菜作为药食两用。作为食物，其鲜嫩滑腻，用来调羹作汤，清香浓郁，被视为宴席上的珍贵食品。据《本草纲目》记载[5]，莼菜具有消渴热痹、治热疸、厚肠胃、安下焦、逐水、解百药毒等功效。……