Production and isolation of chitosan from Aspergillus terreus and application in tin(II) adsorption

Fed‐batch fermentation was used for biomass and fungal chitosan production by Aspergillus terreus (BCRC 32068) grown in a potato dextrose agar medium. The polysaccharides were extracted by an alkali–acid treatment, and structural investigations by X‐ray diffraction, Fourier transform infrared analysis, and viscosity and thermal analysis were done. A high level of chitosan was extracted from A. terreus; this implied that it was feasible to produce chitosan from industrial waste mycelia. Fungal chitosan derived from A. terreus showed the highest adsorption capacity for Sn(II). The order of Sn(II) adsorption capacity for these chitosanaceous materials was Fungal chitosan > Chitin > Biomass. Fungal chitosan derived from A. terreus was well correlated with Langmuir's isotherm model. The maximum capacity for Sn(II) sorption deduced from the use of the Langmuir isotherm equation was 303 mg/g; this was significantly higher than that of A. terreus. Fungal chitosan is an easy and cost‐effective material for the abatement of pollution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40436.     

In vitro evaluation of spray‐dried chitosan microspheres crosslinked with pyromellitic dianhydride for oral colon‐specific delivery of protein drugs

Chitosan microspheres have been prepared using a spray‐drying method, and crosslinked with pyromellitic dianhydride. The chemical structure of the modified chitosan was characterized by FTIR spectroscopy and solid state 13C NMR analysis. The particle size and morphology of the crosslinked chitosan were investigated. These microspheres were evaluated for colon‐specific delivery of bovine serum albumin (BSA) as a model protein drug. The results indicate that the drug was released as follows: 37.1 ± 2.8% after 2 h in SGF, 73.1 ± 4.8% after 8 h (2 h in SGF+ 6 h in SIF), and 80.9 ± 4.1% after 12 h in SCF. The effect of β‐glucosidase on the drug release was also examined. The encapsulation efficiency was decreased from 88.4 ± 3.1% to 62.8 ± 2.9%, with increasing BSA concentration. Loading capacity was significantly increased from 6.3 ± 0.3% to 41.8 ± 4.1% by increasing the initial BSA concentration. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40514.     

Maximizing the Retention of Ganoderic Acids and Water-Soluble Polysaccharides Content of Ganoderma lucidum Using Two-Stage Dehydration Method

Ganoderic acids and water-soluble polysaccharides are the main bioactive ingredients of Ganoderma lucidum and are heat sensitive. Hence, it is crucial to apply a suitable drying method for the drying of G. lucidum to minimize the loss of these bioactive ingredients. In this study, a two-stage drying method was applied to enhance the drying kinetics, as well as the retention of both ganoderic acids and water-soluble polysaccharides in dried G. lucidum fruiting bodies and slices compared to other single-stage-dried products. The results showed that two-stage drying enhanced the overall drying rate, which consequently shortened the total drying time up to 61 and 330% for fruiting bodies and slices, respectively, compared to single-stage drying methods. Furthermore, two-stage drying of Ganoderma fruiting bodies, which involves 18-h vacuum drying followed by 5-h heat pump drying, maximized the retention of ganoderic acids and water-soluble polysaccharides, with the retention of 97.90% of water-soluble polysaccharides and 4.2% more ganoderic acids than freeze-dried products. On the other hand, drying of Ganoderma slices within the shortest total drying time, which is 10-min heat pump drying followed by 50-min oven drying, also retained most of the ganoderic acids and water-soluble polysaccharides in the dried products; that is, about 80% of water-soluble polysaccharides and 11% more ganoderic acids than freeze-dried slices.     

Plant Cell Walls as Dietary Fibre: Range,Structure, Processing and Function

The ingestion of dietary fibre has been correlated with the prevention of many health-threatening diseases and cancers. Plant cell walls are the major source of dietary fibre and this review investigates the relationship between the structure of different types of plant cell walls and their beneficial effects. The effects of processing and cooking on dietary fibre are also examined. Structure–function relationships between individual cell wall components and the beneficial effects of dietary fibre are not well defined and it may be that the physical, physiochemical and topochemical properties of plant cell walls and their components are also important.     

太子参化学成分及生物活性研究进展

太子参为石竹科植物孩儿参的干燥块根,味甘、微苦,性平,归脾肺经,具有益气健脾、生津润肺之功效,常用于气虚津伤的肺虚燥咳,被国家卫生健康委员会批准用于保健食品。现代药理和临床研究表明,太子参中特征性化学成分多糖和环肽具有免疫调节、抗炎、改善记忆等作用。近年来对太子参的化学成分、结构和药理作用的综述仅局限于特征成分,对其他成分还鲜有系统梳理报道。因此本文系统梳理了太子参的化学成分及生物活性研究进展,以期为太子参的开发利用提供参考和依据。     

柳茶多糖对高热环境秀丽隐杆线虫运动的影响及其机制研究

目的 研究纯化后柳茶多糖对高热环境秀丽隐杆线虫运动的影响。方法 超声辅助提取制备的柳茶多糖经DEAE Sepharose Fast Flow葡聚糖凝胶和Sephadex G100葡聚糖纯化后得到两种柳茶多糖(SLP-1和SLP-2)对其进行结构分析及高热线虫运动试验。结果 SLP-1和SLP-2是13.5 kDa左右的含硫酸根的三螺旋结构酸性多糖。SLP-1多糖是由鼠李糖、葡萄糖、半乳糖、果糖和阿拉伯糖组成,而SLP-2多糖不含果糖。在提高秀丽隐杆线虫热刺激运动能力上, SLP-2表现更为优异,其机制是通过上调热休克因子1信使核糖核酸(heat shock factor1 messenger ribonucleic acid, hsf-1 m RNA)来抵御高热环境对机体造成的损伤,上调热休克蛋白16.2信使核糖核酸(heat shock protein 16.2 messenger ribonucleic acid, hsp-16.2 m RNA)、热休克蛋白70信使核糖核酸(heat shock protein 70 messenger ribonucleic acid,hsp-7...     

红芪多糖提取、分离纯化及药理作用研究进展

红芪作为甘肃的大宗药材,以“米仓红芪”为佳,主要含有红芪多糖类、黄酮类、苯丙素类、生物碱类、有机酸类等化学成分。大量研究表明,红芪多糖是红芪药材主要活性成分之一,具有抗炎、抗肿瘤、抗氧化、免疫调节等多种药理作用,在医药保健、食品等领域有良好的应用前景。本文通过文献检索,梳理并总结近10年国内外红芪多糖的提取、分离纯化以及药理活性研究,通过阐述红芪多糖提取工艺、含量测定方法的优缺点,总结红芪多糖的单糖组成、结构特征,分析红芪多糖研究的发展趋势,为红芪多糖的进一步研究和开发利用提供一定参考依据。     

Design-Expert软件设计优化内黄大枣多糖的硒化修饰及其抗氧化、抗疲劳作用研究

目的 优化硒化大枣多糖的制备工艺,并研究其抗氧化和抗疲劳作用。方法 采用硝酸-亚硒酸钠法修饰制备硒化大枣多糖,以内黄大枣多糖为原料,以硒含量为指标,通过单因素实验和Design-Expert软件设计响应面实验确定硒化大枣多糖的最佳制备工艺。同时研究其对1,1-二苯基-2-苦基肼(1,1-diphenyl-2-bitter hydrazine, DPPH)自由基和羟基自由基清除能力和对小鼠的抗疲劳作用。结果 最佳制备工艺条件为:硝酸浓度0.5%、反应温度70℃、反应时间8.2 h,该条件下,硒含量为2.53%。体外抗氧化实验表明,当样品质量浓度为5 mg/mL时,硒化大枣多糖对DPPH自由基和羟基自由基清除率分别为83.36%和79.29%,均高于大枣多糖;硒化大枣多糖对DPPH自由基和羟基自由基的半抑制浓度(half maximal inhibitory concentration, IC₅₀)值分别为0.799和1.145,表明硒化大枣多糖具有较强的抗氧化能力。小鼠的抗疲劳实验表明,硒化大枣多糖能够增加小鼠游泳时间,降低小鼠体内的血乳酸(blood lactic...     

超声酶解法提取桑叶功能性物质的工艺条件优化

目的 探究超声酶解法中不同因素对桑叶黄酮、生物碱及多糖提取含量的影响,并对工艺条件进行优化。方法 以3种物质(黄酮、生物碱和多糖)的提取含量为考察指标,首先确定不同酶种类对3种物质提取含量的影响,通过单因素试验得到溶液pH、酶添加量、超声功率、超声时间、乙醇体积分数和料液比的最佳条件,再利用响应面法对提取工艺进行优化,得出最佳提取工艺条件。结果 最适酶种类为复合酶(纤维素酶与果胶酶比例为1:1,m:m);最佳工艺条件为酶解温度50℃、超声时间50min、料液比1:46(g/mL)、超声功率360 W、乙醇体积分数60%、酶添加量2.0%、溶液pH=6.0, 3种物质提取含量分别为黄酮(39.84±0.59) mg/g、生物碱(14.62±0.41) mg/g、多糖(202.82±1.94) mg/g。结论 超声酶解法能有效提高桑叶中黄酮、生物碱和多糖的提取含量,且复合酶效果最好,优化后的工艺条件准确可靠,可用于桑叶黄酮、生物碱及多糖的提取。     

Chitosan-based fiber-sponge materials as a promising tool for microalgae harvesting from Lake Baikal

Mass eutrophication of microalgae and cyanobacteria is observed in Lake Baikal in the past decade. In this paper, the concept of replaceable adsorption filter material based on chitosan flocculant filler and chlorinated polyvinyl chloride polymer nonwoven material are proposed. Functional and mechanical properties and morphology of the material are investigated depending on a packing density and a degree of chitosan filling. The introduction of 45% chitosan increases the Young's modulus up to 10 times, and it makes the material more rigid in 2.8 times. The high efficiency of sorption and growth inhibition of cumulative biomass culture was shown. The biomass source is taken from the coast of Barguzinsky Bay of Lake Baikal. Dominant species is microalgae of Scenedesmus genus.