Ultrasound-assisted extraction of water-soluble polysaccharides from the roots of valerian (Valeriana officinalis L.)

The insoluble plant residues, obtained after preparation of medicinal tinctures from the roots of valerian (Valeriana officinalis L.) by classical and ultrasound-assisted extraction with aqueous ethanol in a pilot plant, were subsequently treated with hot water to isolate the accessible polysaccharide cell wall components. At almost equal amounts of the hot-water extractable material, the yields of the recovered polysaccharides were lower in the ultrasonical experiment. This is due to the fact that a part of accessible polysaccharides were already solubilised by the aqueous ethanol and recoverable from the medicinal tincture. Therefore, the net yield of extracted polysaccharides was enhanced in the ultrasonical procedure. This fact as well as the sugar composition and structural features of the isolated polysaccharides suggest that ultrasonication have attacked the integrity of cell walls, released and degraded its most accessible polysaccharides (pectic polysaccharides and starch) and increased also the extractibility of its less accessible components--xylan, mannan and glucan. The water-soluble polysaccharide fractions from both the conventional and ultrasonical experiments exhibit significant immunostimulatory activities in mitogenic and comitogenic thymocyte tests.     

超声波强化提取对茯苓水溶性多糖结构影响的研究

以茯苓菌核为原料,采用正交实验法确定超声波辅助热水浸提茯苓水溶性多糖的最佳提取条件,并对超声波辅助提取中药多糖的机理进行初步研究。用苯酚硫酸法测定糖含量,傅立叶变换红外光谱仪(FTIR)分析糖类官能团,气相色谱法测定单糖组成,原子力显微镜观察多糖结构,并将测定结果与传统热水法浸提所得茯苓多糖进行对比。实验结果表明:采用超声波辅助热水浸提可以使水溶性茯苓多糖的提取率达到2.71%(传统热水浸提法提取率为1.49%),传统热水浸提得茯苓多糖(PPTH)与超声波辅助热水浸提得茯苓多糖(PPUH)具有相同的单糖组成,都包含核糖、木糖、甘露糖、果糖、半乳糖和葡萄糖,二者的红外吸收谱也基本相同,原子力显微镜扫描分析显示,PPTH整体呈现网状结构,而PPUH主要以长短不一的近棒状结构存在。     

白僵蚕多糖的甲醇提取与热水提取工艺的比较

建立了白僵蚕多糖的甲醇提取法,采用正交设计,优化了提取工艺,并采用传统的热水提取法验证了新工艺的应用效果。结果表明,甲醇提取法可以有效的应用于白僵蚕多糖的制备。最佳工艺为:浸提温度55℃,浸提时间4h,提取次数2次,料液比1∶40。甲醇提取法提取的多糖得率为11.21%。而热水提取法的多糖得率为10.14%。甲醇提取法的多糖得率优于热水提取法。     

Ultrasonic extraction of plant materials--investigation of hemicellulose release from buckwheat hulls

Various one- and two-step extraction procedures with and without a short application of ultrasound at the beginning of the extraction were used to examine the effect of sonication on the extractibility of the hemicellulose components of buckwheat hulls. The polysaccharides recovered from the extracts were characterised by yield as well as composition determined by chemical methods and spectroscopic techniques. They comprised a complex of glucuronoxylan and co-extracted amylose-rich starch in various proportions contaminated with other cell wall components (protein, pectic polysaccharides). The hemicellulose fractions obtained by classical and ultrasound-assisted extraction exhibited significant immunomodulatory activities. The increased yield of ultrasonically extracted hemicelluloses, which have preserved their structural and molecular properties as well as immunological activity, confirmed the importance and great potential of ultrasound-assisted extraction of industrially important polysaccharides from different tissues of plant materials.     

热水回流提取香椿叶多糖的工艺研究

研究热水回流提取香椿叶总多糖的工艺条件。单因素考察了原料粒度、提取温度、提取时间、料液比对香椿叶总多糖提取量的影响。以香椿叶总多糖提取量为考察指标,选用L9(34)试验设计对香椿叶总多糖的热水回流提取工艺条件进行优化,并验证最佳工艺条件、确定提取次数。其最佳工艺条件为:在原料粒度约为40目的条件下,提取温度为90℃,提取时间为3h,料液比为1∶25,提取次数为5次。在最佳参数组合下,每克香椿叶可提取总多糖为34.783mg。     

胡萝卜多糖含量的测定

采用热水浸提、乙醇分级沉淀和洗涤等步骤提取胡萝卜中的多糖,通过苯酚-硫酸比色法测定多糖的含量,选择490nm作为检测波长,在5-60μtg范围内葡萄糖质量浓度和吸光度呈良好的线性关系,相关系数r为0.9997,相对标准偏差RSD为1.86％,平均回收率为99.61％,胡萝卜中多糖含量为6.02％.本方法简便、快速、准确、重现性好,可作为胡萝卜多糖含量的测定方法,对于综合开发利用胡萝卜及提高胡萝卜品质的研究能提供一定参考依据.     

Ultrasound-assisted extraction and characteristics of maize polysaccharides from different sites

Antitumor, antioxidant, hypoglycemic, and immunomodulatory properties are all exhibited by maize polysaccharides. With the increasing sophistication of maize polysaccharide extraction methods, enzymatic method is no longer limited to a single enzyme to extract polysaccharides, and is more often used in combination with ultrasound or microwave, or combination with different enzymes. Ultrasound has a good cell wall-breaking effect, making it easier to dislodge lignin and hemicellulose from the cellulose surface of the maize husk. The “water extraction and alcohol precipitation” method is the simplest but most resource- and time-consuming process. However, the “ultrasound-assisted extraction” and “microwave-assisted extraction” methods not only compensate for the shortcoming, but also increase the extraction rate. Herein, the preparation, structural analysis, and activities of maize polysaccharides were analyzed and discussed.     

Ultrasound-assisted polysaccharide extraction from Cercis chinensis and properites,antioxidant activity of polysaccharide

The purpose of the study was to improve the extraction of polysaccharide from the leaves of Cercis chinensis Bunge using ultrasound, and compare the difference between boiling and ultrasound extraction in terms of polysaccharide content, monosaccharide compounds, and evaluate how the factors affected the bioactivity. The best conditions, according to the single factor experiments and the Box-Bohnken design (BBD), were an intensity of ultrasound of 180 W, duration of extraction of 40 min, proportion of water to material of 15:1 (g/g), and a higher polysaccharide yield of 20.02 ± 0.55 (mg/g) than in boiling extraction (16.09 ± 0.82 mg/g). The antioxidative experiment suggested the polysaccharide by ultrasound exhibited higher DPPH, hydroxyl radical scavenging capacities, and reducing power at 1.2–1.4 mg/mL, which was superior to the boiling polysaccharide. Further analysis showed that the ultrasonic purified polysaccharides like Gla, N-Glu, and GluA contained more total sugar and uronic acids than the boiling method did. This may indicate that the ultrasonic isolation of the polysaccharides increase the antioxidant activity of the polysaccharides.     

粗江蓠多糖的提取及光谱分析

采用热水浸提和乙醇沉淀的方法提取粗江蓠多糖(gracilaria gigas harvey polysacchrides,GHPS),用苯酚-硫酸法测定糖含量,等离子体原子发射光谱(ICP)测多糖中矿物元素的含量,傅里叶红外光谱仪(FTIR)分析糖类官能团.结果表明:采用热水浸提和乙醇沉淀的方法提取粗江蓠多糖提取率达14.98%,苯酚-硫酸法测得提取物多糖含量为78.2%;ICP测得粗江蓠多糖含Ca,Fe,Mg和S等矿物元素;FTIR分析GHPS有一般糖类物质的特征吸收峰,是一种酸性多糖,同时存在呋喃环和吡喃环.     

蒙药嘎日迪-15中多糖的研究

用热水提取蒙药嘎日迪-15中水溶性多糖,经SephadexC-25进行提纯精制得纯糖,采用硫酸-苯酚法测定了其水溶性多糖含量.方法的平均回收率为100.50%,RSD为0.82%.用GC测定了蒙药嘎日迪-15中水溶性多糖主要由木糖、甘露糖、半乳糖、葡萄糖组成,其摩尔比为1.03:1.26:0.77:2.30.用溴化钾压片法测得的红外谱图显示多糖的特征吸收峰为3 417.46,2 928.65,1 742.86,1 643.69,1 149.78,1 078.19,1 022.56,834.57 cm-1,其中1 078.19和1 022.56 cm-1为吡喃糖特征峰,834.57 cm-1是α-吡喃糖苷键的特征吸收峰.紫外谱图在280 nm处有明显的糖吸收峰,说明有C=O键存在.