Preparation and functional evaluation of agarose derivatives

A facile microwave‐assisted one‐pot synthesis of sodium carboxymethylagarose and calcium carboxymethylagarose from Gracilaria dura agarose (Ag) has been described. The process is user friendly, and the highest degree of substitution was obtained within 15 min compared with the conventional method, which requires more than 3 h. Solubility and gelling behavior of the modified Ag products were found to be dependent on degree of substitution of the products. The characterizations were done by using Fourier transform infrared spectroscopy, ¹H‐ and ¹³C‐nuclear magnetic resonance spectroscopy, thermogravimetric analysis, scanning electron microscopy, Inductively coupled plasma spectrophotometry (ICP), rheology, conductometer analysis, and DNA gel electrophoresis. These agarose derivatives were easily soluble in water and exhibited low thermal hysteresis, improved conductivity, and improved the DNA resolution ability of the parent G. dura Ag hydrogels. These hydrogels may have potential applications in the areas including electrochemical devices, microbiology, biomedical, and pharmaceuticals fields. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40630.     

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.     

TEOS as an improved alternative for chitosan beads cross‐linking: A comparative adsorption study

In this work the use of tetraethoxysilane (TEOS) for cross‐linking of chitosan hydrogel beads was studied at the level of 1 mmol TEOS per gram of chitosan. They were compared with glutaraldehyde and epichlorohydrin cross‐linked beads. The hydrogels were characterized by FTIR, SEM, water content, nitrogen content, and their point of zero charge. The performance of the anionic dye Remazol Black (RB) and the cationic Cd(II) adsorptions was assessed in order to characterize the sorbate–sorbent interaction. Adsorption experimental data were analyzed using two‐ and three‐parameter isotherm models along with the evaluation of mean adsorption energy and standard free energy. The adsorption was observed to be pH dependent. The uptake rate of RB and Cd(II) showed that the three type of beads followed a similar kinetic behavior. For both sorbates the TEOS cross‐linked beads showed the higher maximum adsorption capacity, followed by epichlorohydrin and glutaraldehyde cross‐linked beads. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41005.     

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.     

湄潭白茶多糖对金黄色葡萄球菌的抑菌活性及其稳定性

目的:研究湄潭白茶多糖对金黄色葡萄球菌的体外抑菌活性及其稳定性.方法:采用牛津杯法和微量肉汤稀释法测定湄潭白茶多糖对金黄色葡萄球菌的抑菌活性及最小抑菌浓度(Minimum inhibitory concentration,MIC),并进一步探讨温度、pH、紫外线照射和金属离子对其抑菌活性稳定性的影响.结果:湄潭白茶多糖...     

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.     

Faecal Composition and Nitrogen Excretion of Rats Fed on Diets Containing Sweet Lupin (Lupinus angustifoliusL) or its Fractions

Five N balance studies were conducted to determine the faecal composition and N excretion of feeding raw Lupinus angustifolius seed meal and its fractions for growing rats using a semi-synthetic lactalbumin-based diet as control. Diets were formulated to have equal amounts of energy. The protein was incorporated at the level of 10% bulk and contained unsupplemented lupin seed meal (LMU) and fully supplemented lupin seed meal (LMFS) at 360 g kg⁻¹ diet, aqueous extract non-dialysed (LPAND) at 196 g kg⁻¹ aqueous extract dialysed soluble at pH 7·0 (LPAD) at 148 g kg⁻¹ aqueous extract dialysed insoluble at pH 7·0 (LPADI) at 124 g kg⁻¹, buffer dialysed soluble at pH 7·0 (BUSOL) at 136 g kg⁻¹, buffer dialysed insoluble at pH 7·0 (BUDI) at 119 g kg⁻¹ and lupin meal residue after aqueous and buffer extraction (LMR) at 170 g kg⁻¹ diet. Rats were pair-fed for 10 days with all the above diets which had been supplemented with essential amino acids up to the target requirements for rats. Faecal wet and dry weight were increased in rats fed on LMU, LMPS and LMR diets compared to those obtained from the control diet based on lactalbumin (milk protein) LACT. The higher faecal weight was largely due to water content. The higher faecal N excretion observed in LMU, LMFS, LPAND, LPAD, BUSOL, BUDI and LMR compared to that of LACT diet was significantly lower and thus which was assumed not to be due to a decrease in the digestibility of the dietary protein, which was over 90% as compared to that in the control group. Analysis suggested that an increase in endogenous N excretion is involved in the rise of its excretion in the faeces, and indicates a long-term effect of this seed as a protein and or fibre source in monogastrics.     

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...