Antioxidant and Biological Activities of the Lotus Root Polysaccharide-Iron (III) Complex

In this study, the synthesis parameters of the lotus root polysaccharide iron complex (LRPF) were determined and optimized by response surface methodology. Under the optimum preparation conditions, the pH of the solution was 9, the ratio of M (trisodium citrate): m (lotus root polysaccharide) was 0.45, the reaction time was 3 h. UV spectroscopy, thermogravimetry, FT-IR spectroscopy, X-ray diffraction, CD, and NMR were used for the characterization of the LRPF. LRPF has good stability and easily releases iron ions under artificial gastrointestinal conditions. LRPF exhibited antioxidant activity in vitro and can significantly improve the antioxidant activity in vivo. In addition, LRPF has a good effect in the treatment of iron deficiency anemia in model mice, impacts the gut microbiome, and reduces the iron deficiency-induced perniciousness by regulating steroid hormone biosynthesis. Therefore, LRPF can be used as a nutritional supplement to treat and prevent iron-deficiency anemia and improve human immunity.     

Comparison of the Antioxidant Activities and Polysaccharide Characterization of Fresh and Dry Dendrobium officinale Kimura et Migo

It is generally believed that fresh Dendrobium officinale (FDO) has more significant pharmacological activity than dried Dendrobium officinale (DDO); however, the difference has not been clearly shown. Our study compared their antioxidant properties both in vitro and in vivo, and the molecular weight arrangement and monosaccharide composition of the fresh Dendrobium officinale polysaccharides (FDOPs) and the dried Dendrobium officinale polysaccharides (DDOPs) were analyzed by HPLC-GPC and GC-MS. The results showed that the FDO and its polysaccharides had more significant effects on scavenging DPPH, ABTS, and hydroxyl radicals than the DDO. In addition, both the FDO and DDO significantly reduced lipid peroxidation levels and increased the SOD, T-AOC, CAT, and GSH levels in mice with acute liver damage caused by CCl₄, while the FDO and its polysaccharides were more effective. Histopathological analysis further verified the protective effect of the Dendrobium polysaccharides on CCl₄-induced liver injury. The determination of the polysaccharides revealed that the polysaccharide and mannose contents of the FDO were significantly higher than their dried counterparts, and the homogeneous arrangement of the polysaccharides in the FDO was degraded into three polysaccharide fragments of different molecular weights in the DDO. Overall, our data identified differences in the antioxidant activities of the FDO and DDO, as well as the reasons for these differences.     

无花果多糖的分离、纯化和鉴定

经脱脂、沸水抽提、乙醇沉淀、酶-Sevag法脱蛋白得到粗多糖,再经DEAE-Sepharose fast flow阴离子交换层析和Sephadex G-200葡聚糖凝胶柱层析得到纯化的无花果多糖(FCPS),用红外光谱和紫外光谱分析鉴定该多糖.红外光谱分析具有典型的多糖特征吸收峰,紫外光谱分析未见蛋白质(280 nm)与核酸(260 nm)的特征吸收峰.结果表明,所提取的无花果多糖为单一组分的多糖.     

紫心甘薯多糖对四氯化碳肝损伤小鼠的保护作用

研究紫心甘薯多糖对四氯化碳(CCl4)诱导小鼠免疫性肝损伤的保护作用及可能作用机制.以不同剂量的紫心甘薯多糖200、400、800 mg.(kg.d)-1分别给予小鼠灌胃,设立对照组,连续10 d作预处理,腹腔注射0.1%的CCl410 ml.kg-1建立CCl4诱导小鼠肝损伤模型.测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)酶活力、总胆红素(TBIL)、总蛋白(TP)含量,测定肝组织中超氧化物岐化酶(SOD)、谷胱甘肽(GSH)、丙二醛(MDA)水平,并进一步观察肝组织病理组织学变化.紫心甘薯多糖各剂量组均能明显地抑制血清中ALT、AST、LDH、TBIL的升高和TP的下降,降低肝脏中MDA的含量,提高肝组织中SOD和GSH活性,减轻CCl4对肝脏细胞的病理损伤.紫心甘薯多糖对CCl4致小鼠急性肝损伤具有明显保护作用,其作用机理可能与抗氧化作用有关.     

羊栖菜多糖的提取和分离

羊栖菜多糖是从马尾藻科植物羊栖菜（Sargassum fusiforme(Harv.)Setchel)中提取到的，具有抗肿瘤，抗凝血，降血糖，提高机体免疫功能等生理活性，本文研究用水提法提取羊栖菜多糖，考虑到提取温度，时间，加水量等因素的影响，优化提取条件，确定水提法的最佳温度80℃，提取时间3h，水加量为羊栖菜样品的3倍，并采用乙醇沉淀，透析及凝胶层析等方法对羊栖菜提取物中多糖进行沉淀，提取和分离获得4个组分，并用光谱扫描法，凝胶色谱和旋光度法鉴定其纯度，进一步研究其分离获得的组分对生物体免疫功能指标的影响。     

Affinity of Hemicellulose for Cellulose Produced by Acetobacter Xylinum

Cellulose composites were produced by culturing Acetobacter aceti subsp. xylinum (ATCC 53524, agitation tolerant strain) under shaking and agitating conditions in the presence of 2% pine or beech Björkman lignin-carbohydrate complexes (LCCs) or six different types of hemicellulosic polysaccharides including glucuronoxylan, glucomannan, O-acetyl-glucuronoxylan, arabinoglucuronoxylan, arabinogalactan and xyloglucan. Hemicellulosic polysaccharide contents in cellulose composites were similar in spite of the differences in culture, shaking and agitating conditions. On the basis of hemicellulosic polysaccharide contents and X-ray diffraction patterns after extraction by dilute NaOH solution, glucomannan family polysaccharides were found to have the highest affinity to bacterial cellulose. Composites with neutral and acidic LCCs were resistant against alkali while high lability of their delignified carbohydrates against alkali indicates the importance of lignin for formation of cellulose-hemicellulose-lignin framework of plant secondary cell-walls.     

多糖化学合成研究进展

多糖是一类结构复杂的生物大分子,广泛分布于微生物、植物、动物等生物体中,参与众多重要的生命过程.然而,多糖研究一直受限于难以获得足量结构均一的多糖物质,这使得多糖的结构和功能研究及其相关的应用研究进展缓慢.近几十年来,随着糖合成技术的进步,糖的化学合成效率不断提高,人们开始关注复杂多糖的化学合成,并取得了一些进展.本文主要对多糖化学合成所涉及的糖基化方法、糖组装策略和代表性的合成工作进行综述,并对研究前景进行展望.     

Determination of Polysaccharide Hydrolyzates in Chinese Herbal Medicine by UltraHigh-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry and Evaporative Light Scattering Detection

Ultrahigh-performance liquid chromatography coupled with evaporative light scattering detector was used to optimize acid hydrolysis conditions of polysaccharides from Dendrobium candidum. The optimized conditions were the concentration of H₂SO₄, 0.4?M, hydrolysis temperature, 90°C, and hydrolysis time, 1?h. Ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used to obtain the total ion current chromatograms and determine the hydrolyzates of polysaccharides, such as monosaccharides, oligosaccharides, and some low-molecular weight polysaccharides from D. candidum, Cordyceps sinensis, and Ganoderma atrum. The accurate mass data were analyzed by chemometric tools, including an unsupervised analytical method, principal component analysis (one-way ANOVA, p?D. candidum polysaccharides from different locations and grades can be discriminated effectively by the principal component analysis scores. The quality predictive models showed a high value with a low prediction error calculated from both validation and training sets.     

Determination of Polysaccharides in Undaria pinnatifida by Ionic Liquid-Modified Silica Gel Size Exclusion Chromatography

Ionic liquid-modified silica particles with a large pore size were synthesized and used as the stationary phase for size exclusion chromatography coupled with a refractive index detector for the determination of polysaccharides, such as fucoidan, alginic acid, and laminarin from Undaria pinnatifida (seaweed). The molecular weight of polysaccharide was determined by a dextran standard curve (5–1100?kDa). The ionic liquid-modified silica column exhibited excellent size exclusion properties in separating laminarin from other components. The 1-butyl-3-methyl-imidazolium bis-(trifluoromethylsulfonyl)-amino silica column has superior resolution in laminarin separation than the other columns because the amino-group in ionic liquid provide π–π interactions due to aromaticity of the ring structure, which enhances the effect of the hydroxyl group in the target compound separation. The concentrations of polysaccharides were calculated using a standard linear equation to be 0.332–0.484?mg/g of fucoidan, 0.207–0.301?mg/g of alginic acid, and 0.154–0.297?mg/g of laminarin.