Galactans

Galactans
  • 文章类型: Journal Article
    豆类是丰富的蛋白质来源,白豆蛋白在空气-水界面特性中起着重要作用。本研究旨在研究白豆分离蛋白(BPI)的技术功能特性与pH值的关系。蛋白质浓度,和瓜尔胶(GG)存在。根据溶解度分析了BPI的理化性质,zeta电位,和pH值为2至9时的平均粒径,除了持水量(WHC)外,持油能力(OHC),和热重分析。蛋白质分散在动态方面进行了评估,界面,和泡沫形成特性。BPI在pH2和高于7时显示出更高的溶解度(>80%)。Zeta电位和平均直径范围为15.43至-34.08mV和129.55至139.90nm,分别。BPI表现出1.37和4.97g/g的WHC和OHC,分别。热谱图显示分解温度(295.81°C)和质量损失(64.73%)。流动曲线表明假塑性行为,在含有瓜尔胶的处理中观察到更高的η100值。在较低频率下,行为主要是粘性的(tgδ>1),在所有pH值水平,在更高的频率下转移到主要的弹性。平衡表面张力(γeq)范围为43.87至41.95mN。m-1,并且在所有pH条件下都没有随着蛋白质浓度的增加而降低。所有处理均表现为Φ<15°,表明主要是弹性表面膜。发泡性能受到较高的蛋白质浓度和瓜尔胶添加量的影响,蛋白质-多糖复合物的潜在形成有利于系统的动力学稳定性。
    Legumes are abundant sources of proteins, and white common bean proteins play an important role in air-water interface properties. This study aims to investigate the technical-functional properties of white common bean protein isolate (BPI) as a function of pH, protein concentration, and guar gum (GG) presence. BPI physicochemical properties were analyzed in terms of solubility, zeta potential, and mean particle diameter at pH ranging from 2 to 9, in addition to water-holding capacity (WHC), oil-holding capacity (OHC), and thermogravimetric analysis. Protein dispersions were evaluated in terms of dynamic, interfacial, and foam-forming properties. BPI showed higher solubility (>80 %) at pH 2 and above 7. Zeta potential and mean diameter ranged from 15.43 to -34.08 mV and from 129.55 to 139.90 nm, respectively. BPI exhibited WHC and OHC of 1.37 and 4.97 g/g, respectively. Thermograms indicated decomposition temperature (295.81 °C) and mass loss (64.73 %). Flow curves indicated pseudoplastic behavior, with higher η100 values observed in treatments containing guar gum. The behavior was predominantly viscous (tg δ > 1) at lower frequencies, at all pH levels, shifting to predominantly elastic at higher frequencies. Equilibrium surface tension (γeq) ranged from 43.87 to 41.95 mN.m-1 and did not decrease with increasing protein concentration under all pH conditions. All treatments exhibited ϕ < 15°, indicating predominantly elastic surface films. Foaming properties were influenced by higher protein concentration and guar gum addition, and the potential formation of protein-polysaccharide complexes favored the kinetic stability of the system.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    分枝杆菌物种中不断升级的抗生素耐药性在全球范围内构成了重大威胁,迫切需要找到替代解决方案。噬菌体来源的内溶素,通过攻击细菌细胞壁促进噬菌体后代的释放,由于其快速的裂解作用,目前有希望的抗菌候选物,特异性高,耐药性发展风险低。在分枝杆菌中,由于复杂,疏水细胞壁,分枝杆菌噬菌体通常合成两种内溶素:LysinA,水解肽聚糖;LysinB,将含霉菌酸的外膜和阿拉伯半乳聚糖脱钩,释放游离的霉菌酸。在这项研究中,我们对来自RitSun的新型LysinB进行了域分析和功能表征,我们收集的F2亚簇分枝杆菌噬菌体。RitSunLysinB的几个关键特性使其成为一种重要的抗分枝杆菌剂:它能够从无,a高于先前报道的1.36U/mg的比活性及其对生物膜形成的抑制作用。鉴于分枝杆菌细胞包膜的不可渗透性质,在分子水平上解剖RitSunLysinB以鉴定其细胞壁不稳定序列可用于将其他天然溶素工程化为融合蛋白,扩大他们的活动范围。
    The escalating antibiotic resistance in mycobacterial species poses a significant threat globally, necessitating an urgent need to find alternative solutions. Bacteriophage-derived endolysins, which facilitate phage progeny release by attacking bacterial cell walls, present promising antibacterial candidates due to their rapid lytic action, high specificity and low risk of resistance development. In mycobacteria, owing to the complex, hydrophobic cell wall, mycobacteriophages usually synthesize two endolysins: LysinA, which hydrolyzes peptidoglycan; LysinB, which delinks mycolic acid-containing outer membrane and arabinogalactan, releasing free mycolic acid. In this study, we conducted domain analysis and functional characterization of a novel LysinB from RitSun, an F2 sub-cluster mycobacteriophage from our phage collection. Several key properties of RitSun LysinB make it an important antimycobacterial agent: its ability to lyse Mycobacterium smegmatis from without, a higher than previously reported specific activity of 1.36 U/mg and its inhibitory effect on biofilm formation. Given the impermeable nature of the mycobacterial cell envelope, dissecting RitSun LysinB at the molecular level to identify its cell wall-destabilizing sequence could be utilized to engineer other native lysins as fusion proteins, broadening their activity spectrum.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    RSA-1是一种从萝卜属精液中获得的多糖,具有相对清晰的结构和抗结肠癌活性。在这项研究中,高效液相色谱(HPLC),气相色谱-质谱(GC-MS),和核磁共振(NMR)光谱用于表征RSA-1的复杂链结构。随后,探讨了通过诱导结肠癌细胞凋亡对结肠癌生长的抑制作用。研究结果表明,RSA-1的主链由→3)-β-D-Galp-(1→和3,6)-β-D-Galp-(1→在C-6处被支链α-L-Araf侧链取代。RSA-1破坏Bax/Bcl-2比例,从而在体外抑制结肠癌细胞的活力。此外,它通过减弱上皮-间质转化来抑制结肠癌的迁移。值得注意的是,RSA-1在相关浓度范围内对人肠上皮细胞生长的影响可忽略不计。本研究为RSA-1作为一种双重用途的抗结肠癌药物和功能性食品的开发和应用奠定了理论基础和技术支持。
    RSA-1 is a polysaccharide obtained from Raphani semen with a relatively clear structure and anti-colon cancer activity. In this study, high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy were applied to characterise the complex chain structure of RSA-1. Subsequently, the inhibitory effect on colon cancer growth through apoptosis induction in colon cancer cells was explored. The findings indicate that the main chain of RSA-1 consists of →3)-β-D-Galp-(1 → and 3,6)-β-D-Galp-(1 → substituted at C-6 with branched α-L-Araf side chains. RSA-1 disrupts the Bax/Bcl-2 ratio and thus inhibits the viability of colon cancer cells in vitro. Furthermore, it inhibits colon cancer migration by attenuating epithelial-mesenchymal transition. Notably, RSA-1 exhibited negligible impact on the growth of human intestinal epithelial cells within a relevant concentration range. This study establishes a theoretical foundation and provides technical support for the prospective development and application of RSA-1 as a dual-purpose anti-colon cancer drug and functional food.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    研究了杜比裂子菌(Nemastomatales)的多糖体系。它含有杂合dl半乳聚糖(SH-S)和角叉菜胶样多糖的混合物,通过用高浓度KCl沉淀分离。通过甲基化分析研究了卡拉胶样级分(SH-I)的结构特征,脱硫,糖醛酸还原,和NMR光谱。结论是该结构具有典型的交替性α-(1→3),d-半乳糖单元的β-(1→4),大多数3-连接单元在O-2中被硫酸化(有些在O-4中),和大多数4-连接的单元在O-3中硫酸化,并在O-2中被β-d-葡萄糖醛酸的单个残根取代(在三个可用位置中的每个位置都部分硫酸化)。在红海藻半乳聚糖中很少发现这种取代基。5%和10%w/vSH的流变学研究,SH-S和SH-I水系统,要么没有离子,或在KCl或CaCl2溶液中产生增稠行为。它们的无规卷曲构象证明了在粘度与剪切速率曲线中观察到的假塑性行为。由于SH-S和SH-I都包含在SH中,在葡萄糖醛酸卡拉胶和琼脂之间的SH中可以形成互穿网络,从水中记录的机械光谱推断,尤其是钾离子.
    The system of polysaccharides from Schizymenia dubyi (Nemastomatales) was investigated. It contains a mixture of hybrid dl galactans (SH-S) and carrageenan-like polysaccharides, which were separated by means of precipitation with KCl at high concentrations. The structural features of the carrageenan-like fraction (SH-I) were investigated by methylation analysis, desulfation, uronic acid reduction, and NMR spectroscopy. It was concluded that the structure has the typical alternance α-(1 → 3), β-(1 → 4) of d-galactose units, with most of the 3-linked units sulfated in O-2 (and some in O-4), and most of the 4-linked units sulfated in O-3, and substituted in O-2 by single stubs of β-d-glucuronic acid (partly sulfated in each of the three available positions). This substituent has been only seldom found in red seaweed galactans. Rheological studies of 5 % and 10 % w/v SH, SH-S and SH-I aqueous systems, either without ions, or in KCl or CaCl2 solution gave thickening behaviors. Their random coil conformations justify the pseudoplastic behavior observed in the viscosity versus shear rate curves. As SH-S and SH-I are both contained in SH, an interpenetrating network could form in SH between the glucurono-carrageenan and the agaran, as inferred from the mechanical spectra recorded in water, especially with potassium ion.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    目的:本工作旨在配制和评价含有阿莫西林的粘膜粘附微球在幽门螺杆菌治疗中的有效应用。
    方法:使用乳化-交联技术制备微球。将该瓜尔胶(GG)和藻酸钠(SA)溶于200ml水中,并使其在室温下溶胀24小时。分别将壳聚糖(CH)溶解在2%(v/v)冰醋酸中,并保持24小时以适当溶胀或溶解。24小时后,在磁力搅拌器(Remi,印度)以特定的搅拌速率搅拌1小时,以找到两种树胶的均匀质量。然后还将壳聚糖的浆料均质化半小时。药物,然后将阿莫西林(1g)加入到壳聚糖溶液中并均匀混合。
    结果:研究的目的是配制和评估微球,用于所选药物的SR。微球的粒径在200-500µ的范围内,最佳配方F-9观察到的最大粘膜粘附特性为57.41%,药物释放68.52%至8小时,F-9制剂的最大截留率为94.87%。该工作还旨在研究影响口服剂型微球行为的各种参数。
    结论:从胃肠道(GIT)吸收的半衰期短的药物从血流中迅速消除。为了避免这种情况,口服SR是由于该制剂将药物缓慢释放到GIT中并在更长的时间内维持血清中的稳定药物浓度而开发的。
    OBJECTIVE: This work is aimed to formulate and evaluate Mucoadhesive Microspheres contain Amoxicillin for the effective use in the treatment of H.Pylori.
    METHODS: Microspheres were prepared using Emulsification-cross linking technique. To this guar gum (GG) and sodium alginate (SA) was dissolved in 200 ml of water and allowed to swell for 24 h at room temperature. And separately chitosan (CH) was dissolved in 2% (v/v) glacial acetic acid and this also kept for 24 h to swell or dissolve properly. After 24 h this swelled mixture was mixed under magnetic stirrer (Remi, India) at specific stirring rate for 1 h in order to find homogeneous mass of both the gum. Then slurry of chitosan also was homogenized for half an hour. The drug, Amoxicillin (1g) was then added to the chitosan solution and mixed homogeneously.
    RESULTS: The aim of the study was to formulate and evaluate microspheres, for SR of the chosen drug. The particle size of microspheres was in the range of 200-500 µ, maximum mucoadhesive property observed was 57.41% for Optimized formulation F-9, Drug release 68.52% till 8 h, and the maximum entrapment was 94.87% for F-9 formulation. The work also aims to study various parameters affecting the behavior of microspheres in oral dosage form.
    CONCLUSIONS: Drugs with short half life that are absorbed from the gastrointestinal tract (GIT) are eliminated rapidly from the blood flow. To avoid this, the oral SR was developed as this formulation released the drug slowly into the GIT and maintained a stable drug concentration in the serum for a longer duration of time.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    来自煤层气的微生物对瓜尔胶的生物降解可导致低温凝胶破裂,从而减少储层损害。然而,对盐度对煤和瓜尔胶协同生物降解的影响的关注有限。在这项研究中,在不同盐度条件下进行了瓜尔胶和褐煤的生物降解实验。主要目的是研究盐度对褐煤和瓜尔胶协同降解的控制作用和机理。研究结果表明,盐度对褐煤和瓜尔胶共同降解产生的生物甲烷具有抑制作用。生物甲烷产量随着盐度水平的增加而下降,从120.9mL减少到47.3mL。即使在20g/L盐胁迫条件下,煤层中的细菌可以有效地破坏凝胶,粘度降低到5mPas以下。随着盐度的增加,可溶性化学需氧量(SCOD)去除率由55.63%降至31.17%,和挥发性脂肪酸(VFAs)积累在消化系统中。高盐环境降低了每个荧光峰的强度。盐度的改变导致微生物群落结构和多样性的变化。在盐胁迫下,蛋白质和甲烷细菌的相对丰度增加,确保厌氧消化的连续性。与乙酸碎屑产甲烷菌相比,氢营养产甲烷菌表现出更高的耐盐性。这些发现提供了实验证据,支持在不同盐度水平的煤层中使用瓜尔胶压裂液。
    The biodegradation of guar gum by microorganisms sourced from coalbeds can result in low-temperature gel breaking, thereby reducing reservoir damage. However, limited attention has been given to the influence of salinity on the synergistic biodegradation of coal and guar gum. In this study, biodegradation experiments of guar gum and lignite were conducted under varying salinity conditions. The primary objective was to investigate the controlling effects and mechanisms of salinity on the synergistic biodegradation of lignite and guar gum. The findings revealed that salinity had an inhibitory effect on the biomethane production from the co-degradation of lignite and guar gum. The biomethane production declined with increasing salinity levels, decreasing from 120.9 mL to 47.3 mL. Even under 20 g/L salt stress conditions, bacteria in coalbeds could effectively break the gel and the viscosity decreased to levels below 5 mPa s. As salinity increased, the removal rate of soluble chemical oxygen demand (SCOD) decreased from 55.63% to 31.17%, and volatile fatty acids (VFAs) accumulated in the digestion system. High salt environment reduces the intensity of each fluorescence peak. Alterations in salinity led to changes in microbial community structure and diversity. Under salt stress, there was an increased relative abundance of Proteiniphilum and Methanobacterium, ensuring the continuity of anaerobic digestion. Hydrogentrophic methanogens exhibited higher salt tolerance compared to acetoclastic methanogens. These findings provide experimental evidence supporting the use of guar gum fracturing fluid in coalbeds with varying salinity levels.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    肠内配方中特定营养素的排空率知之甚少,尽管控制管饲患者的排空率很重要。由于它们的粘度,增稠配方广泛用于避免胃反流和减轻护理人员的负担。这项研究检查了肠内配方中的增稠剂如何影响蛋白质和碳水化合物的胃排空率。半动态胃模型用于制备和消化不含增稠剂或琼脂(0.2%)的测试肠内配方。确定每个清空的等分试样中蛋白质和碳水化合物的量,并计算了排空率。我们发现琼脂加速蛋白质排空,用琼脂(0.5%)进行的探索性实验表明了浓度依赖性的可能性。此外,使用结冷胶(0.08%)的实验,瓜尔胶(0.2%),或角叉菜胶(0.08%,0.2%)表明蛋白质排空可能因增稠剂类型而异,而角叉菜胶可能会减慢其速度。这些结果可能有助于根据患者的代谢概况适当选择添加到液体食物中的增稠剂来管理营养,不仅适用于管饲患者,也适用于口咽吞咽困难或糖尿病患者。
    The emptying rate of specific nutrients in enteral formulas is poorly understood, despite the importance of controlling the emptying rate in tube-fed patients. Because of their viscosity, thickened formulas are widely used to avoid gastric reflux and reduce the burden on caregivers. This study examined how thickeners in enteral formulas affected the gastric emptying rates of proteins and carbohydrates. A semi-dynamic gastric model was used to prepare and digest test enteral formulas that contained either no thickeners or agar (0.2%). The amounts of protein and carbohydrates in each emptied aliquot were determined, and the emptying rate was calculated. We found that agar accelerated protein emptying, and an exploratory experiment with agar (0.5%) suggested the possibility of concentration dependence. Additionally, experiments using gellan gum (0.08%), guar gum (0.2%), or carrageenan (0.08%, 0.2%) suggested that protein emptying could vary depending on the thickener type and that carrageenan might slow it. These results could help with the appropriate selection of thickeners added to liquid foods based on the patient\'s metabolic profile to manage nutrition, not only for tube-fed patients but also for those with oropharyngeal dysphagia or diabetes.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    咖啡饮料是由阿拉伯半乳聚糖组成的膳食纤维的来源,也可以与蛋白质和酚类化合物有关,源自黑素。人结肠体外发酵咖啡部分,一种富含黑素(Mel),另一种富含其亲本多糖阿拉伯半乳聚糖(AG),是为了评估微生物群产生的代谢物,即短链脂肪酸(SCFA),酚类化合物,和胆汁酸。发酵48小时后,观察到AG(62%)的碳水化合物部分的发酵能力高于Mel(27%),导致SCFA含量为63mM和22mM,分别。补充AG和Mel馏分将乙酸盐:丙酸盐的比例分别从4.7(在没有咖啡馏分的情况下)降低到2.5和3.5,提示HMG-CoA还原酶的潜在抑制作用,胆固醇合成的限速酶。咖啡馏分的发酵产生了二氢阿魏酸和二氢咖啡酸,已知具有抗氧化性能。在梅尔面前,观察到次级胆汁酸的产生减少(从0.25到0.16mg/mL),其高含量与几种疾病的发展有关,比如结肠直肠癌,神经退行性疾病和心血管疾病。
    Coffee beverage is a source of dietary fiber composed by arabinogalactans, which can also be associated to proteins and phenolic compounds, originating melanoidins. Human colonic in vitro fermentations of coffee fractions, one rich in melanoidins (Mel) and the other in its parental polysaccharide arabinogalactans (AG), were performed in order to evaluate the metabolites produced by microbiota, namely short-chain fatty acids (SCFA), phenolic compounds, and bile acids. After 48 h of fermentation, a higher fermentability of the carbohydrate fraction of AG (62 %) than that of Mel (27 %) was observed, resulting in a SCFA content of 63 mM and 22 mM, respectively. Supplementation with AG and Mel fractions decreased the acetate:propionate ratio from 4.7 (in the absence of coffee fractions) to 2.5 and 3.5, respectively, suggesting a potential inhibition of HMG-CoA reductase, a rate-limiting enzyme for cholesterol synthesis. The fermentation of coffee fractions yielded dihydroferulic and dihydrocaffeic acids, known to have antioxidant properties. In the presence of Mel, it was observed a decrease (from 0.25 to 0.16 mg/mL) in the production of secondary bile acids, whose high content is associated to the development of several diseases, such as colorectal cancer, neurodegenerative and cardiovascular.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    伤口在医疗保健方面构成了巨大的挑战,需要探索创新的组织愈合解决方案。传统的伤口敷料表现出缺点,造成组织损伤和阻碍自然愈合。使用微波(MW)-)辅助技术,我们设想了一种新型的水凝胶(Hg)支架来应对这些挑战。这种水凝胶支架是通过合成一种pH响应性交联材料,特别是刺槐豆胶接枝的聚(丙烯酰胺-共-丙烯酸)[LBG-g-聚(AAm-co-AAc)],以实现c-藻蓝蛋白(C-Pc)的持续释放。通过调整各种合成参数对合成的LBG-g-poly(AAm-co-AAc)进行微调,包括单体的浓度,反应时间,和MW辐照强度,最大限度地提高交联LBG接枝产物的收率,提高C-Pc的包封率。在其合成之后,LBG-g-poly(AAm-co-AAc)使用先进技术进行了彻底表征,像XRD,TGA,FTIR,NMR,和SEM,分析其结构和化学性质。此外,该研究检查了基于LBG-g-聚(AAm-co-AAc)的水凝胶(HgCPcLBG)的体外C-Pc释放曲线。研究结果表明,C-Pc的最大释放(64.12±2.69%)在pH7.4超过48小时。HgCPcLBG表现出增强的抗氧化性能和与血液的相容性。体内研究证实伤口加速闭合,和ELISA结果显示炎症标志物减少(IL-6,IL-1β,TNF-α)在治疗的皮肤组织内,提示对损伤修复的积极影响。已开发出一种低成本且环保的方法来创建LBG-g-聚(AAm-co-AAc)和HgCPcLBG。该方法实现了C-Pc的持续释放,这可能是伤口护理技术向前迈出的重要一步。
    Wounds pose a formidable challenge in healthcare, necessitating the exploration of innovative tissue-healing solutions. Traditional wound dressings exhibit drawbacks, causing tissue damage and impeding natural healing. Using a Microwave (MW)-)-assisted technique, we envisaged a novel hydrogel (Hg) scaffold to address these challenges. This hydrogel scaffold was created by synthesizing a pH-responsive crosslinked material, specifically locust bean gum-grafted-poly(acrylamide-co-acrylic acid) [LBG-g-poly(AAm-co-AAc)], to enable sustained release of c-phycocyanin (C-Pc). Synthesized LBG-g-poly(AAm-co-AAc) was fine-tuned by adjusting various synthetic parameters, including the concentration of monomers, duration of reaction, and MW irradiation intensity, to maximize the yield of crosslinked LBG grafted product and enhance encapsulation efficiency of C-Pc. Following its synthesis, LBG-g-poly(AAm-co-AAc) was thoroughly characterized using advanced techniques, like XRD, TGA, FTIR, NMR, and SEM, to analyze its structural and chemical properties. Moreover, the study examined the in-vitro C-Pc release profile from LBG-g-poly(AAm-co-AAc) based hydrogel (HgCPcLBG). Findings revealed that the maximum release of C-Pc (64.12 ± 2.69 %) was achieved at pH 7.4 over 48 h. Additionally, HgCPcLBG exhibited enhanced antioxidant performance and compatibility with blood. In vivo studies confirmed accelerated wound closure, and ELISA findings revealed reduced inflammatory markers (IL-6, IL-1β, TNF-α) within treated skin tissue, suggesting a positive impact on injury repair. A low-cost and eco-friendly approach for creating LBG-g-poly(AAm-co-AAc) and HgCPcLBG has been developed. This method achieved sustained release of C-Pc, which could be a significant step forward in wound care technology.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    为分枝杆菌阿拉伯半乳聚糖的六糖阿拉伯聚糖结构域提供了针对B(C6F5)3指导的β-选择性阿拉伯呋喃糖基化的通用方法,证明了β-阿拉伯呋喃糖基化策略的有效性。还原端的氨基部分的衍生化是阐明生物合成途径和将该化合物与蛋白质载体缀合以产生疫苗的必要先决条件。
    The hexasaccharide arabinan domain of Mycobacterial Arabinogalactan was provided with the versatile methodology toward β-selective arabinofuranosylation directed by B(C6F5)3, demonstrating the effectiveness of the β-arabinofuranosylation strategy. Derivatization of the amino moiety at the reducing end are essential prerequisites for elucidating the biosynthetic pathway and conjugating of this compound to a protein carrier for vaccine generation.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号