Siga este link para ver outros tipos de publicações sobre o tema: Polysaccharide.
Artigos de revistas sobre o tema "Polysaccharide"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores artigos de revistas para estudos sobre o assunto "Polysaccharide".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja os artigos de revistas das mais diversas áreas científicas e compile uma bibliografia correta.
1
Al-Wraikat, Majida, Yun Liu, Limei Wu, Zeshan Ali e Jianke Li. "Structural Characterization of Degraded Lycium barbarum L. Leaves’ Polysaccharide Using Ascorbic Acid and Hydrogen Peroxide". Polymers 14, n.º 7 (30 de março de 2022): 1404. http://dx.doi.org/10.3390/polym14071404.
Texto completo da fonteResumo:
Plant-derived polysaccharide’s conformation and chain structure play a key role in their various biological activities. Lycium barbarum L. leaves’ polysaccharide is well renowned for its health functions. However, its functional bioactivities are greatly hindered by its compact globular structure and high molecular weight. To overcome such issue and to improve the functional bioactivities of the polysaccharides, degradation is usually used to modify the polysaccharides conformation. In this study, the ethanol extract containing crude Lycium barbarum L. leaves’ polysaccharide was first extracted, further characterized, and subsequently chemically modified with vitamin C (Ascorbic acid) and hydrogen peroxide (H2O2) to produce degraded Lycium barbarum L. leaves’ polysaccharide. To explore the degradation effect, both polysaccharides were further characterized using inductively coupled plasma mass spectrometry (ICP-MS), gas chromatography–mass spectrometry (GC–MS), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), high performance gel permeation chromatography (HPGPC), and scanning electron microscope (SEM). Results shown that both polysaccharides were rich in sugar and degradation had no significant major functional group transformation effect on the degraded product composition. However, the molecular weight (Mw) had decreased significantly from 223.5 kDa to 64.3 kDa after degradation, indicating significant changes in the polysaccharides molecular structure caused by degradation.
2
Khalilova, Gulnoza Abduvahobovna, Abbaskhan Sabirkhanovich Turaev, Bakhtiyor Ikromovich Muhitdinov, Al'bina Vasil'yevna Filatova, Saida Bokizhonovna Haytmetova e Nodirali Sokhobatalievich Normakhamatov. "ISOLATION, PHYSICO-CHEMICAL CHARACTERISTICS OF POLYSACCHARIDE ISOLATED FROM THE FRUIT BODY OF INONOTUS HISPIDUS". chemistry of plant raw material, n.º 3 (27 de setembro de 2021): 99–106. http://dx.doi.org/10.14258/jcprm.2021039028.
Texto completo da fonteResumo:
The article is devoted to the study of polysaccharides isolated from the basidiomycete raw material I. hispidus and studying their physical and chemical properties. Water-soluble polysaccharides were isolated from mushroom raw materials by the method of sequential water extraction and the yield was 9.44%. Polysaccharides were separated into neutral fractions by ion exchange chromatography and purified from proteins and peptides. During the separation process, it was determined that the polysaccharide sample consisted of homogeneous polysaccharides, while the carbohydrate content of the purified polysaccharide sample was 99.4%. The carbohydrate composition of polysaccharides was determined, it was found that the polysaccharide consists mainly of glucose residues and contains minor amounts of fructose and rhamnose residues. Molecular weight and molecular weight distribution were determined by size exclusion chromatography. The Mw of the polysaccharide sample obtained was 18.7 kDa, the polydispersity index was 1.3. The results of IR-, 1H- and 13C NMR spectroscopic studies have shown that the polysaccharide, according to its structural characteristics, belongs to the β-glucan type polysaccharide having β-(1,3) and β-(1,6)-glycosidic bounds.
3
Whang, Yoon Hee, Soo Kyung Kim, Hyeseon Yoon, Seuk Keun Choi, Yeong Ok Baik, Chankyu Lee e Inhwan Lee. "Reduction of free polysaccharide contamination in the production of a 15-valent pneumococcal conjugate vaccine". PLOS ONE 15, n.º 12 (10 de dezembro de 2020): e0243909. http://dx.doi.org/10.1371/journal.pone.0243909.
Texto completo da fonteResumo:
Glycoconjugate vaccines are vaccines in which a bacterial polysaccharide antigen is conjugated to a carrier protein to enhance immunogenicity by promoting T cell-dependent immune response. However, the free (unreacted) polysaccharides remaining after the conjugation process can inhibit the immunogenicity of a conjugate vaccine. Thus, we aimed to reduce the unbound free polysaccharides in the polysaccharide-protein conjugation process for the development of a new 15-valent pneumococcal conjugate vaccine (PCV15) by varying some factors that may affect the conjugation results such as polysaccharide/protein ratio, polysaccharide size, and concentration of a coupling agent in a conjugation reaction mixture. Concentrations of a coupling agent, carbodiimide (EDAC), and a carrier protein (CRM197) used in PCV15 production, during the conjugation process, had little effect on the content of free polysaccharides. However, the size of the polysaccharide was identified as the critical factor to control the free polysaccharide content, with an inverse relationship observed between the molecular weight of the polysaccharide and the residual free polysaccharide content after conjugation. Based on these results, a new PCV15 with low free polysaccharide contamination was produced and tested for immunogenicity using a rabbit model to show that it induces similar level of immune responses in rabbits compared to a comparator vaccine Prevnar13®.
4
Schifferle, R. E., H. J. Jennings, M. R. Wessels, E. Katzenellenbogen, R. Roy e D. L. Kasper. "Immunochemical analysis of the types Ia and Ib group B streptococcal polysaccharides." Journal of Immunology 135, n.º 6 (1 de dezembro de 1985): 4164–70. http://dx.doi.org/10.4049/jimmunol.135.6.4164.
Texto completo da fonteResumo:
Abstract The types Ia and Ib group B streptococcal type-specific polysaccharides have remarkable immunologic differences despite a great deal of structural similarity. Although these two complex polysaccharides differ only by a single glycosidic linkage, they are antigenically distinct. Furthermore, terminal sialic acid residues appear to be critical to the immunodeterminant on the type Ia polysaccharide, whereas the antigenicity of the type Ib polysaccharide does not show this dependence on sialic acid. In the current investigation we defined better the immunodeterminant of these polysaccharides. With homologous rabbit antiserum, the type Ia native and core polysaccharides demonstrated partial serologic identity, whereas the type Ib native and core polysaccharides demonstrated complete serologic identity. Surprisingly, the type I degalactosylated polysaccharide, degraded structure, was capable of reacting with a population of antibodies present in type Ia antiserum similar to the complete type Ia native polysaccharide, although demonstrating a reduced level of immunodeterminant expression. Unlike the reactions of the type Ia polysaccharides with homologous rabbit antiserum, the Ib native and core polysaccharides were able to react with identical populations of antibodies in type Ib-specific antiserum. A minor population of antibodies was demonstrated in the type Ib antiserum, which was reactive with the degalactosylated polysaccharide. That a population of antibodies reactive toward the degalactosylated polysaccharide is present in both type Ia and type Ib antisera suggests that the Iabc cross-reacting determinant is due to the presence of serum antibodies reactive with this trisaccharide repeating unit, which is shared by both the type Ia and the type Ib native and core polysaccharides.
5
Guo, Qingbin, Xingyue Xiao, Laifeng Lu, Lianzhong Ai, Meigui Xu, Yan Liu e H. Douglas Goff. "Polyphenol–Polysaccharide Complex: Preparation, Characterization, and Potential Utilization in Food and Health". Annual Review of Food Science and Technology 13, n.º 1 (25 de março de 2022): 59–87. http://dx.doi.org/10.1146/annurev-food-052720-010354.
Texto completo da fonteResumo:
Polysaccharides and polyphenols coexist in many plant-based food products. Polyphenol–polysaccharide interactions may affect the physicochemical, functional, and physiological properties, such as digestibility, bioavailability, and stability, of plant-based foods. In this review, the interactions (physically or covalently linked) between the selected polysaccharides and polyphenols are summarized. The preparation and structural characterization of the polyphenol–polysaccharide conjugates, their structural–interaction relationships, and the effects of the interactions on functional and physiological properties of the polyphenol and polysaccharide molecules are reviewed. Moreover, potential applications of polyphenol–polysaccharide conjugates are discussed. This review aids in a comprehensive understanding of the synthetic strategy, beneficial bioactivity, and potential application of polyphenol–polysaccharide complexes.
6
Yang, Haiyan, Dawei Wang, Jia Deng, Jing Yang, Chun Shi, Fanglang Zhou e Zhengjun Shi. "Activity and Structural Characteristics of Peach Gum Exudates". International Journal of Polymer Science 2018 (3 de junho de 2018): 1–5. http://dx.doi.org/10.1155/2018/4593735.
Texto completo da fonteResumo:
Polysaccharide fractions were prepared from peach gum exudates by treatments with alkaline hydrogen peroxide (AHP) and liquid hot water (LHW). The structural characteristics and activities of the polysaccharide fractions were comparatively studied. The results suggested that arabinogalactans substituted with xylose and uronic acids were the main structure of all polysaccharide fractions. AHP and LHW treatments introduced the degradation of the polysaccharides, reducing the molecular weight of polysaccharides from 182500 g/mol to 78450 g/mol and 68420 g/mol, respectively. The decreasement of molecular weights responded to the decrease of thermal stability of polysaccharide fractions. However, AHP and LHW treatments removed most of the nonsugar composition, increasing the DPPH•- and ABTS•+-scavenging activity of polysaccharides. Polysaccharide fractions obtained from LHW treatment showed favorable DPPH•- and ABTS•+-scavenging activity at 22.9% and 34.3%, respectively, at concentration of 1000 μg/mL.
7
Li, Jingyuan, Hong Xiang, Qian Zhang e Xiaoqing Miao. "Polysaccharide-Based Transdermal Drug Delivery". Pharmaceuticals 15, n.º 5 (14 de maio de 2022): 602. http://dx.doi.org/10.3390/ph15050602.
Texto completo da fonteResumo:
Materials derived from natural plants and animals have great potential for transdermal drug delivery. Polysaccharides are widely derived from marine, herbal, and microbial sources. Compared with synthetic polymers, polysaccharides have the advantages of non-toxicity and biodegradability, ease of modification, biocompatibility, targeting, and antibacterial properties. Currently, polysaccharide-based transdermal drug delivery vehicles, such as hydrogel, film, microneedle (MN), and tissue scaffolds are being developed. The addition of polysaccharides allows these vehicles to exhibit better-swelling properties, mechanical strength, tensile strength, etc. Due to the stratum corneum’s resistance, the transdermal drug delivery system cannot deliver drugs as efficiently as desired. The charge and hydration of polysaccharides allow them to react with the skin and promote drug penetration. In addition, polysaccharide-based nanotechnology enhances drug utilization efficiency. Various diseases are currently treated by polysaccharide-based transdermal drug delivery devices and exhibit promising futures. The most current knowledge on these excellent materials will be thoroughly discussed by reviewing polysaccharide-based transdermal drug delivery strategies.
8
Savidge, Rodney Arthur, e J. Ross Colvin. "Production of cellulose and soluble polysaccharides by Acetobacter xylinum". Canadian Journal of Microbiology 31, n.º 11 (1 de novembro de 1985): 1019–25. http://dx.doi.org/10.1139/m85-192.
Texto completo da fonteResumo:
Alkali-insoluble cellulose and water-soluble polysaccharide production by wild-type Acetobacter xylinum colony and liquid cultures was investigated. The mass of cellulose exceeded that of soluble polysaccharides in liquid cultures while the reverse situation occurred in colony cultures. The soluble polysaccharide fraction, 3 × 105 to 5 × 105 in molecular weight, was found by DEAE-Sephacel chromatography to be a complex of several acidic, nitrogenfree polysaccharides. One acidic polysaccharide was predominant in the complex, and gas–liquid chromatography and mass spectrometry showed this to contain glucose, rhamnose, mannose, and glucuronic acid in molar ratio of 6:1:1:1, respectively. 13C and 1H nuclear magnetic resonance spectra are presented for this major polysaccharide component. Several minor, soluble, acidic polysaccharides were related in chemical composition to the major soluble polymer. The relation of these soluble polysaccharides to cellulose biogenesis is discussed.
9
Wang, Zi, Ju-Hong Chen, Ling-Shuai Wang, Juan Ding, Ming-Wen Zhao e Rui Liu. "GlPP2C1 Silencing Increases the Content of Ganodermalingzhi Polysaccharide (GL-PS) and Enhances Slt2 Phosphorylation". Journal of Fungi 8, n.º 9 (10 de setembro de 2022): 949. http://dx.doi.org/10.3390/jof8090949.
Texto completo da fonteResumo:
Polysaccharides have attracted much attention in the food industry due to their diverse biological activities. To date, research on the mechanism of polysaccharide synthesis has mainly focused on the role of crucial enzymes in the polysaccharide synthesis pathway, but other genes that regulate polysaccharide synthesis have not been well explored. In this study, the GlPP2C1 gene, encoding a phosphoprotein type 2C phosphatase, was cloned, and PP2C-silenced strains (PP2C1i-1 and PP2C1i-3) were screened. Measurements of the polysaccharide content and cell wall tolerance revealed that GlPP2C1 silencing increased the polysaccharide content and enhanced cell wall resistance in Ganoderma lingzhi. The contents of intracellular polysaccharides (IPS), extracellular polysaccharides (EPS) and β-1,3-D-glucan in PP2C-silenced strains were increased by 25%, 33% and 36%, respectively, compared with those in the WT strains and strains transformed with an empty vector. Further mechanistic studies showed that GlPP2C1 silencing increased the content of Ganoderma lingzhi polysaccharides (GL-PS) through Slt2. In summary, this study revealed the mechanism through which protein phosphatase regulates GL-PS biosynthesis for the first time.
10
Wang, Qiong, Mengmeng Xu, Liting Zhao, Lei Chen e Zhongyang Ding. "Novel Insights into the Mechanism Underlying High Polysaccharide Yield in Submerged Culture of Ganoderma lucidum Revealed by Transcriptome and Proteome Analyses". Microorganisms 11, n.º 3 (17 de março de 2023): 772. http://dx.doi.org/10.3390/microorganisms11030772.
Texto completo da fonteResumo:
Polysaccharides are crucial dietary supplements and traditional pharmacological components of Ganoderma lucidum; however, the mechanisms responsible for high polysaccharide yields in G. lucidum remain unclear. Therefore, we investigated the mechanisms underlying the high yield of polysaccharides in submerged cultures of G. lucidum using transcriptomic and proteomic analyses. Several glycoside hydrolase (GH) genes and proteins, which are associated with the degradation of fungal cell walls, were significantly upregulated under high polysaccharide yield conditions. They mainly belonged to the GH3, GH5, GH16, GH17, GH18, GH55, GH79, GH128, GH152, and GH154 families. Additionally, the results suggested that the cell wall polysaccharide could be degraded by GHs, which is beneficial for extracting more intracellular polysaccharides from cultured mycelia. Furthermore, some of the degraded polysaccharides were released into the culture broth, which is beneficial for obtaining more extracellular polysaccharides. Our findings provide new insights into the mechanisms underlying the roles that GH family genes play to regulate high polysaccharide yields in G. lucidum.
11
Phomkaivon, Naraporn, Preeyanut Pongponpai, Prapat Kosawatpat, Bussaba Thongdang e Wanida Pan-utai. "Extraction, Characterisation and Evaluation of Antioxidant and Probiotic Growth Potential of Water-Soluble Polysaccharides from Ulva rigida Macroalgae". Foods 13, n.º 11 (23 de maio de 2024): 1630. http://dx.doi.org/10.3390/foods13111630.
Texto completo da fonteResumo:
Ulva rigida green macroalgae contain a variety of polysaccharides. A recent study investigated the optimum concentration and yield of polysaccharide extraction from oven-dried U. rigida biomass using a water-soluble polysaccharide extraction method that adhered to safety standards. This study utilised complete factorial experiments to examine the effects of varying factors on polysaccharide extraction. Results showed a positive correlation between increased levels of all factors and higher polysaccharide extraction yield. This study also found that the main factors and their interaction had a significant impact on the extracted polysaccharides from U. rigida. The highest polysaccharide content and yield were 9.5 mg/mL and 189 mg/g, respectively. Water-soluble polysaccharides demonstrated the presence of reducing sugar (8 mg/g), phenolics (0.69 mg/g) and flavonoids (1.42 mg/g) and exhibited antioxidant properties. Results revealed that freeze-dried polysaccharide powders were primarily composed of the monosaccharide rhamnose. Preliminary results on the effect of these powders on probiotics demonstrated that supplementation of polysaccharides from U. rigida promoted viable Lactobacillus rhamnosus ATCC 53103 growth during cultivation. This discovery has the potential to revolutionise the human food industry and promote the development of functional ingredients for novel and future food products, with numerous applications in the nutraceutical and pharmaceutical industries.
12
Yong, Raymond N., e Diana Mourato. "Influence of polysaccharides on kaolinite structure and properties in la kaolinite–water system". Canadian Geotechnical Journal 27, n.º 6 (1 de dezembro de 1990): 774–88. http://dx.doi.org/10.1139/t90-091.
Texto completo da fonteResumo:
The influence of soil organics on the development of soil structure and behaviour of soils is the motivation for this study. Xanthan and dextran, two soil polysaccharides, were examined in relation to their influence on the development of the structure of kaolinite–polysaccharide systems and also on resultant physicochemical properties. The kaolinite–polysaccharide soils were formed in suspensions under anaerobic and low redox potential conditions to simulate environmental conditions that exist in subsurface soils. Information on the rheology of the kaolinite–polysaccharide system, zeta potential, aggregate size, settling properties, and specific surface area were obtained. Both polysaccharides were shown to develop aggregate groups (floes) which participated to a greater or lesser extent in the overall rheological properties of the kaolinite–polysaccharide complexes. The ability of the polysaccharides to develop flocs is seen as a factor to be considered in studies of soil permeability and transport processes in soil. Together with information from infrared spectroscopy and scanning electron microscopy, and in combination with the results obtained from the physicochemical tests, models of interaction between kaolinite and both polysaccharides are proposed. Key words: soil organics, polysaccharides, kaolinite, rheology, floes, xanthan, dextran, soil structure, zeta potential, kaolinite–polysaccharide system, differential viscosity, Bingham yield stress.
13
Oshchepkova, Yuliya Igorevna, e Shavkat Ismailovich Salikhov. "ISOLATION AND STUDY OF POLYSACCHARIDES OF MARGILAN RADISH RAPHANUS SATIVUS". chemistry of plant raw material, n.º 3 (2 de outubro de 2023): 109–15. http://dx.doi.org/10.14258/jcprm.20230311689.
Texto completo da fonteResumo:
The purpose of this research is to isolate and study the physicochemical characteristics of polysaccharides in the seeds of the Margilan radish of the Brassicaceae family cultivated in the Republic of Uzbekistan.
For the first time, a water-soluble fraction of polysaccharides was isolated from radish seeds by sowing Margilan successive extraction after the extraction of proteins and polyphenols. Anion exchange chromatography and gel filtration were used to obtain homogeneous polysaccharides. The polysaccharide fraction was separated by ion-exchange chromatography, purified on a Sephadex G-100 column. As a result, two polysaccharides RSP1 and RSP2 were obtained. The monosaccharide composition of the isolated polysaccharides was established. Analysis of monosaccharide residues showed that the composition of the RSP1 polysaccharide is represented by monosaccharides in the following composition: rhamnose - 0.7%, ribose - 4.7%, arabinose - 55.6%, xylose - 1.5%, mannose - 3.7%, glucose - 5.1% and galactose - 28.7%. The composition of the RSP2 polysaccharide is represented by monosaccharides: ribose - 2.8%, arabinose - 9.4%, mannose - 0.9%, glucose - 64.9% and galactose - 18.4%. From the obtained results, it can be seen that the RSP1 polysaccharide consists mainly of arabinose (55.6%) and galactose (28.7%) residues and belongs to the type of arabinogalactans, and the RSP2 polysaccharide mainly consists of glucose residues (64.9%) and galactose (18.4%).
14
Ofoedu, Chigozie E., Lijun You, Chijioke M. Osuji, Jude O. Iwouno, Ngozi O. Kabuo, Moses Ojukwu, Ijeoma M. Agunwah et al. "Hydrogen Peroxide Effects on Natural-Sourced Polysacchrides: Free Radical Formation/Production, Degradation Process, and Reaction Mechanism—A Critical Synopsis". Foods 10, n.º 4 (25 de março de 2021): 699. http://dx.doi.org/10.3390/foods10040699.
Texto completo da fonteResumo:
Numerous reactive oxygen species (ROS) entities exist, and hydrogen peroxide (H2O2) is very key among them as it is well known to possess a stable but poor reactivity capable of generating free radicals. Considered among reactive atoms, molecules, and compounds with electron-rich sites, free radicals emerging from metabolic reactions during cellular respirations can induce oxidative stress and cause cellular structure damage, resulting in diverse life-threatening diseases when produced in excess. Therefore, an antioxidant is needed to curb the overproduction of free radicals especially in biological systems (in vivo and in vitro). Despite the inherent properties limiting its bioactivities, polysaccharides from natural sources increasingly gain research attention given their position as a functional ingredient. Improving the functionality and bioactivity of polysaccharides have been established through degradation of their molecular integrity. In this critical synopsis; we articulate the effects of H2O2 on the degradation of polysaccharides from natural sources. Specifically, the synopsis focused on free radical formation/production, polysaccharide degradation processes with H2O2, the effects of polysaccharide degradation on the structural characteristics; physicochemical properties; and bioactivities; in addition to the antioxidant capability. The degradation mechanisms involving polysaccharide’s antioxidative property; with some examples and their respective sources are briefly summarised.
15
Vu Thi, Bach Phuong, Minh Dai Cao e Ngo Diem Phuong Quach. "Extraction and evaluation of α-glucosidase inhibitory activity of polysaccharide from Urena lobata L. roots". Research Journal of Biotechnology 18, n.º 8 (15 de julho de 2023): 11–15. http://dx.doi.org/10.25303/1808rjbt011015.
Texto completo da fonteResumo:
Polysaccharides are compounds found in the roots of Urena lobata L. Polysaccharides are of interest due to many valuable biological activities such as immunomodulatory, anti-cancer, diabetes treatment, anti-inflammatory and antioxidant. In this research, polysaccharides extracted from Urena lobata L. roots were analyzed by GC-MS (Gas Chromatography Mass Spectometry) and GPC (Gel Permeation Chromatography). The results show that the polysaccharide from Urena lobata L. natural roots is a heteropolysaccharide. This polysaccharide has two peaks with the weighted average molecular weights (Mw) as 1.823 x 107 g/mol and 1.139 x 105 g/mol. The monosaccharide composition of this polysaccharide includes rhamnose, arabinose, xyloza, mannose, glucose and galactose with the composition ratios of 13.927, 16.579, 3.174, 5.442, 27.659 and 33.219% respectively. In addition, when investigating the α-glucosidase inhibitory activity of polysaccharide from three types of Urena lobata L. roots cultured under different conditions: natural, in vitro and aeroponics, the results showed that the activity of in vitro hairy root polysaccharide was the best. This shows the potential for the development of biologically active polysaccharide sources by in vitro hairy root culture of Urena lobata L.
16
Lu, Aijing, e Suming Li. "Polysaccharides as a Hydrophilic Building Block of Amphiphilic Block Copolymers for the Conception of Nanocarriers". Pharmaceutics 16, n.º 4 (27 de março de 2024): 467. http://dx.doi.org/10.3390/pharmaceutics16040467.
Texto completo da fonteResumo:
Polysaccharides are gaining increasing attention for their relevance in the production of sustainable materials. In the domain of biomaterials, polysaccharides play an important role as hydrophilic components in the design of amphiphilic block copolymers for the development of drug delivery systems, in particular nanocarriers due to their outstanding biocompatibility, biodegradability, and structural versatility. The presence of a reducing end in polysaccharide chains allows for the synthesis of polysaccharide-based block copolymers. Compared with polysaccharide-based graft copolymers, the structure of block copolymers can be more precisely controlled. In this review, the synthesis methods of polysaccharide-based amphiphilic block copolymers are discussed in detail, taking into consideration the structural characteristics of polysaccharides. Various synthetic approaches, including reductive amination, oxime ligation, and other chain-end modification reactions, are explored. This review also focuses on the advantages of polysaccharides as hydrophilic blocks in polymeric nanocarriers. The structure and unique properties of different polysaccharides such as cellulose, hyaluronic acid, chitosan, alginate, and dextran are described along with examples of their applications as hydrophilic segments in the synthesis of amphiphilic copolymers to construct nanocarriers for sustained drug delivery.
17
Zhao, Yue, Bocheng Yan, Zhaoyu Wang, Mingjing Li e Wei Zhao. "Natural Polysaccharides with Immunomodulatory Activities". Mini-Reviews in Medicinal Chemistry 20, n.º 2 (17 de março de 2020): 96–106. http://dx.doi.org/10.2174/1389557519666190913151632.
Texto completo da fonteResumo:
Natural polysaccharide is a kind of natural macromolecular which can be extracted from plants, fungi, algae, animals, and bacteria. The monosaccharide compositions and glucosidic bonds of polysaccharides from different origins vary substantially. Natural polysaccharides have been shown to possess complex, important and multifaceted biological activities including antitumor, anticoagulant, antioxidative, antiviral, immunomodulatory, antihyperlipidemic and antihepatotoxic activities. Their properties are mainly due to their structural characteristics. It is necessary to develop polysaccharide immunomodulators with potential for preventive or therapeutic action. The present paper summarizes the structural features, immunostimulatory activity and the immunomodulatory mechanisms of natural polysaccharides. In particular, it also provides an overview of representative natural polysaccharide immunomodulators.
18
Pérez-Burgos, María, e Lotte Søgaard-Andersen. "Biosynthesis and function of cell-surface polysaccharides in the social bacterium Myxococcus xanthus". Biological Chemistry 401, n.º 12 (26 de novembro de 2020): 1375–87. http://dx.doi.org/10.1515/hsz-2020-0217.
Texto completo da fonteResumo:
AbstractIn bacteria, cell-surface polysaccharides fulfill important physiological functions, including interactions with the environment and other cells as well as protection from diverse stresses. The Gram-negative delta-proteobacterium Myxococcus xanthus is a model to study social behaviors in bacteria. M. xanthus synthesizes four cell-surface polysaccharides, i.e., exopolysaccharide (EPS), biosurfactant polysaccharide (BPS), spore coat polysaccharide, and O-antigen. Here, we describe recent progress in elucidating the three Wzx/Wzy-dependent pathways for EPS, BPS and spore coat polysaccharide biosynthesis and the ABC transporter-dependent pathway for O-antigen biosynthesis. Moreover, we describe the functions of these four cell-surface polysaccharides in the social life cycle of M. xanthus.
19
Zhang, Jing, Qian Li, Xiaochen Jiang, Xiaojing Li, Ping Dong, Jing Li, Makoto Komiyama e Xingguo Liang. "Effect of sulfated polysaccharides on the digestion of DNA by pepsin under simulated gastric juice in vitro". Food & Function 11, n.º 2 (2020): 1790–97. http://dx.doi.org/10.1039/c9fo02578b.
Texto completo da fonte
20
Han, Cheng-Feng, Shu-Ting Liu, Rong-Rong Yan, Jian Li, Ni Chen, Le-Le Zhang, Shi-Ru Jia e Pei-Pei Han. "Salicylic Acid and Jasmonic Acid Increase the Polysaccharide Production of Nostoc flagelliforme via the Regulation of the Intracellular NO Level". Foods 12, n.º 5 (21 de fevereiro de 2023): 915. http://dx.doi.org/10.3390/foods12050915.
Texto completo da fonteResumo:
To significantly improve the polysaccharide production of Nostoc flagelliforme, a total of 12 chemicals were evaluated for their effects on polysaccharide accumulation. The results showed that salicylic acid and jasmonic acid increased the accumulation of the polysaccharides in N. flagelliforme significantly, by more than 20%. Three polysaccharides, namely control-capsule polysaccharide, salicylic acid-capsule polysaccharide, and jasmonic acid-capsule polysaccharide, were extracted and purified from N. flagelliforme under normal, salicylic acid, and jasmonic acid culture conditions, respectively. Their chemical compositions slightly differed regarding the total sugar and uronic acid contents, with average molecular weights of 2.06 × 103, 2.16 × 103 and 2.04 × 103 kDa, respectively. They presented similar Fourier transform infrared spectra and no significant difference in antioxidant activity. It was revealed that the salicylic acid and jasmonic acid significantly increased the level of nitric oxide. By investigating the effects of the exogenous nitric oxide scavenger and nitric oxide donor on the nitric oxide levels and polysaccharide yield of N. flagelliforme, the results showed that the increase in intracellular nitric oxide levels might be an important factor promoting the accumulation of polysaccharides. These findings provide a theoretical foundation for enhancing the yield of secondary metabolites by regulating the intracellular nitric oxide levels.
21
Yan, Pei Sheng, Li Ya Ma e Li Xin Cao. "Optimization of Enzymatic Hydrolytic Extraction Conditions for High Yield Polysaccharide Manufacturing from Liquid Fermented Materials of Hypsizigus Marmoreus". Applied Mechanics and Materials 145 (dezembro de 2011): 154–58. http://dx.doi.org/10.4028/www.scientific.net/amm.145.154.
Texto completo da fonteResumo:
Polysaccharides extracted from fruiting body and mycelia of higher fungi have been found to show various biological activities. Traditionally, these polysaccharides are manufactured by the hot water extraction method. Low polysaccharide yield is the disadvantage of this method. This paper reports the optimal conditions to manufacture polysaccharide with high-yield from Hypsizigus marmoreus mycelia using enzymatic hydrolytic extraction method. Neutral protease was selected as the most cost efficient among six enzymes. The uniform design was further conducted to optimize the enzymatic hydrolytic extraction conditions, and a regression model was constructed to predict polysaccharide yield. The optimized procedures was that 2% (w/w) of neutral protease was added into hydrolytic solution and incubated for 4 h at 43°C, then extracted one time at 100°C for 1 h. Under optimized procedures, the measured polysaccharide yield was 15.73±0.15 (mg/g), which was very close to the predicted value of 16.65 (mg/g). The results validated the accuracy of the regression model and the optimized procedure. When following the optimized procedures, polysaccharide yield was raised 75.0% over that before optimization, and increased by 122.5% and 104.8% over hot-water extraction and microwave assisted extraction methods respectively. This was the first study to apply uniform design for optimizing high yield manufacture of mycelia polysaccharides by enzymatic hydrolytic extraction. We concluded that enzymatic hydrolytic extraction was a simple, high yield method to manufacture polysaccharides from mushroom mycelia and might be used widely in polysaccharide-derived functional foods production.
22
Toshtemirova, Charos Toshtemirovna, Abdulhamid Abdulvohid ugli Turaboev, Nodirali Sokhobatalievich Normakhamatov e Fotimahon Akbarovna Kodiralieva. "ISOLATION AND STUDY OF THE PHYSICOCHEMICAL PROPERTIES OF POLYSACCHARIDES FROM PLANT MATERIALS GENTIANA OLIVIERI GRISEB". chemistry of plant raw material, n.º 2 (26 de junho de 2023): 87–95. http://dx.doi.org/10.14258/jcprm.20230211777.
Texto completo da fonteResumo:
Methods for isolating and purifying polysaccharides of the aerial part from plant materials of the Gentian Olivier – Gentiana. Olivieri Griseb (family Gentianaceae ) have been developed and studied for the qualitative and quantitative content of polysaccharides in the herb as biologically active components that determine its anti-inflammatory and sequestering (moisture retention agents) effects in the normalization of gastrointestinal disorders. The qualitative and quantitative characteristics of the content of the polysaccharide complex were determined, including water-soluble polysaccharides obtained from a neutral medium with a yield of 6.4%, water-soluble polysaccharides obtained from an acidic medium with a yield of 0.9%, and pectin substances with a yield of 3.8%. The monomeric composition of water-soluble polysaccharides from both neutral and acidic treatments is represented by D-galactose, L-arabinose, and D-glucose. Pectin substances consisting of D-galactose, L-arabinose and D-glucose, D-galacturonic acid dominate the polysaccharide composition of the medicinal plant. They turned out to be highly esterified. The absorption bands of the infrared spectrum of the polysaccharide indicate the presence of α-glycosidic bonds between the residues of D-galacturonic acid in the polysaccharide.
23
Wessels, Michael R., Lawrence C. Paoletti, Hilde-Kari Guttormsen, Francis Michon, Anello J. D’Ambra e Dennis L. Kasper. "Structural Properties of Group B Streptococcal Type III Polysaccharide Conjugate Vaccines That Influence Immunogenicity and Efficacy". Infection and Immunity 66, n.º 5 (1 de maio de 1998): 2186–92. http://dx.doi.org/10.1128/iai.66.5.2186-2192.1998.
Texto completo da fonteResumo:
ABSTRACT In this study, we tested the hypothesis that the immunogenicity and protective efficacy of polysaccharide-protein conjugate vaccines are influenced by three variables: (i) molecular size of the conjugate, (ii) molecular size of the polysaccharide used for conjugation, and (iii) extent of polysaccharide-to-protein cross-linking. Type III group B Streptococcus capsular polysaccharide was linked by reductive amination at multiple sites to tetanus toxoid to create a polysaccharide-protein conjugate (III-TT). A single lot of III-TT was fractionated into small, medium, and large M rpools. Whereas all three conferred protection in a maternal immunization-neonatal challenge model in mice, the smallestM r conjugate evoked less polysaccharide-specific immunoglobulin G (IgG) than the two largerM r conjugates. To test whether the molecular size of the polysaccharide used for conjugation also affected the immunogenicity of the conjugate, vaccines were synthesized using capsular polysaccharides with M rs of 38,000, 105,000, and 349,000. Polysaccharide-specific IgG responses in mice increased with the M r of the polysaccharides, and protective efficacy was lower for the smallest polysaccharide conjugate compared to the other two vaccines. Immunogenicity testing of a series of vaccines prepared with different degrees of polysaccharide-to-protein cross-linking demonstrated higher polysaccharide-specific antibody responses as the extent of cross-linking increased. However, opsonic activity was greatest in mouse antiserum raised to a moderately cross-linked conjugate, suggesting that some antibodies evoked by highly cross-linked conjugates were directed to a nonprotective epitope. We conclude that conjugate size, polysaccharide size, and degree of polysaccharide-protein cross-linking influence the immunogenicity and protective efficacy of III-TT conjugate vaccines.
24
Curiel-Fernández, María, Belén Ayestarán, Zenaida Guadalupe e Silvia Pérez-Magariño. "Polysaccharide content of extracts obtained from unfermented skins from red varieties". BIO Web of Conferences 68 (2023): 02028. http://dx.doi.org/10.1051/bioconf/20236802028.
Texto completo da fonteResumo:
Grape pomace is one of the main by-products generated by wine industry and contains several bioactive compounds such as polysaccharides. They are contained in the cell walls of the grape skins. The variety can be an important factor influencing the polysaccharide content of grapes. Actually, there is great interest in the revaluation of by-products and their incorporation into the production process. Therefore, the aim of this work was to evaluate the polysaccharide content of different extracts obtained from unfermented pomaces of different red grape varieties from Castilla y León. Eight different grape varieties were studied. The polysaccharides from grape pomace was obtained following a flash extraction process and the total polysaccharide content and the molecular weight distribution were estimated by High-Performance Size-Exclusion Chromatography with a Refractive Index Detector. Statistically significant differences were found in the content of total polysaccharides by grape variety varying between 112 and 200 mg/g. Only high and low molecular weight polysaccharide fractions were detected. All varietal extracts presented higher percentage of low molecular weight polysaccharides (50.8-64.3%) than of high molecular weight (35.7-49.2%).
25
Dubashynskaya, Natallia, Daria Poshina, Sergei Raik, Arto Urtti e Yury A. Skorik. "Polysaccharides in Ocular Drug Delivery". Pharmaceutics 12, n.º 1 (24 de dezembro de 2019): 22. http://dx.doi.org/10.3390/pharmaceutics12010022.
Texto completo da fonteResumo:
Polysaccharides, such as cellulose, hyaluronic acid, alginic acid, and chitosan, as well as polysaccharide derivatives, have been successfully used to augment drug delivery in the treatment of ocular pathologies. The properties of polysaccharides can be extensively modified to optimize ocular drug formulations and to obtain biocompatible and biodegradable drugs with improved bioavailability and tailored pharmacological effects. This review discusses the available polysaccharide choices for overcoming the difficulties associated with ocular drug delivery, and it explores the reasons for the dependence between the physicochemical properties of polysaccharide-based drug carriers and their efficiency in different formulations and applications. Polysaccharides will continue to be of great interest to researchers endeavoring to develop ophthalmic drugs with improved effectiveness and safety.
26
Rohrer, Jeffrey S. "Vaccine Quality Ensured by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection". SLAS TECHNOLOGY: Translating Life Sciences Innovation 25, n.º 4 (26 de novembro de 2019): 320–28. http://dx.doi.org/10.1177/2472630319890309.
Texto completo da fonteResumo:
Many important vaccines use bacterial capsular polysaccharides, or shorter polysaccharides or oligosaccharides, derived from the capsular polysaccharides, conjugated to protein. It is imperative that manufacturers understand the carbohydrate composition of these vaccines and deliver a product with a consistent polysaccharide or polysaccharide conjugate composition and content. High-performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD) is a major technique used to understand the carbohydrate composition of these vaccines and ensure product quality. HPAE-PAD separates and detects carbohydrates without analyte derivatization. This paper describes the basics of the HPAE-PAD technique and then reviews how it has been applied to Haemophilus influenzae type b, pneumococcal, meningococcal, group B streptococcal, and Salmonella polysaccharide and corresponding conjugate vaccines.
27
Morais, Victor, e Norma Suarez. "Conjugation Mechanism for Pneumococcal Glycoconjugate Vaccines: Classic and Emerging Methods". Bioengineering 9, n.º 12 (6 de dezembro de 2022): 774. http://dx.doi.org/10.3390/bioengineering9120774.
Texto completo da fonteResumo:
Licensed glycoconjugate vaccines are generally prepared using native or sized polysaccharides coupled to a carrier protein through random linkages along the polysaccharide chain. These polysaccharides must be chemically modified before covalent linking to a carrier protein in order to obtain a more defined polysaccharide structure that leads to a more rational design and safer vaccines. There are classic and new methods for site-selective glycopolysaccharide conjugation, either chemical or enzymatic modification of the polysaccharide length or of specific amino acid residues of the protein carrier. Here, we discuss the state of the art and the advancement of conjugation of S. pneumoniae glycoconjugate vaccines based on pneumococcal capsular polysaccharides to improve existing vaccines.
28
Loganina, V. I., I. A. Pronin, A. A. Karmanov e M. I. Filinova. "RHEOLOGICAL PROPERTIES OF LIME COMPOSITIONS WITH POLYSACCHARIDES ADDITIVES". Bulletin of South Ural State University series "Construction Engineering and Architecture" 24, n.º 1 (2024): 28–33. http://dx.doi.org/10.14529/build240104.
Texto completo da fonteResumo:
Lime compositions with polysaccharide additives are being studied. The results are aimed at creating a new lime plaster composition with improved performance properties. Materials and methods. Standard methods for studying rheological and technological properties were used. Results. The influence of polysaccharides on changes in the rheological properties of lime compositions has been established. It has been established that the introduction of a polysaccharide additive (hydroxyethylcellulose) helps to accelerate the development of plastic strength. The results of infrared spectroscopy indicate a higher content of calcite in the sample with the addition of polysaccharide. The absence of chemical interaction between lime and polysaccharides has been established. Conclusions. The introduction of polysaccharide additives promotes the formation of a structure that improves the performance properties of the lime composite.
29
Olech, Marta, Natalia Nowacka-Jechalke, Maciej Masłyk, Aleksandra Martyna, Wioleta Pietrzak, Konrad Kubiński, Daniel Załuski e Renata Nowak. "Polysaccharide-Rich Fractions from Rosa rugosa Thunb.—Composition and Chemopreventive Potential". Molecules 24, n.º 7 (6 de abril de 2019): 1354. http://dx.doi.org/10.3390/molecules24071354.
Texto completo da fonteResumo:
The huge health-beneficial potential of polysaccharides encourages the search for novel sources and applications of these compounds. One poorly explored source of polysaccharides is the rose. The content and biological activity of polysaccharides in rose organs is an almost completely unaddressed topic, therefore, polysaccharide-rich extracts (crude polysaccharides, CPLs) from petals, leaves, hips, and achenes of Rosa rugosa Thunb. were studied for their composition and the influence on various cellular processes involved in the development of cancer and other civilization diseases. The study revealed the presence of water-soluble and -insoluble polysaccharides (including β-glucans) and protein-polysaccharide conjugates in rose organs. Rose hips were found to be the most abundant source of polysaccharides. Different polysaccharide-rich extracts showed the ability to inhibit pro-inflammatory enzymes (COX-1, COX-2, hyaluronidase), a radical scavenging effect (against DPPH• and ABTS•+), and antiproliferative activity (in the A549 lung and SW480 colon cancer cell lines) in in vitro assays. Therefore, rose crude polysaccharides are very promising and can potentially be used as natural chemopreventive agents.
30
Domenico, Philip, Dana L. Diedrich e David C. Straus. "Extracellular polysaccharide production by Klebsiella pneumoniae and its relationship to virulence". Canadian Journal of Microbiology 31, n.º 5 (1 de maio de 1985): 472–78. http://dx.doi.org/10.1139/m85-088.
Texto completo da fonteResumo:
Klebsiella pneumoniae serotype 1 and serotype 2 and their capsular variants were examined for production of cell-associated capsular polysaccharides and extracellular capsular polysaccharides. The virulence of these organisms in experimental animals was examined via intraperitoneal injection in mice and transtracheal inoculation into the lungs of rats. It was found that the production of either polysaccharide component correlated with the observed virulence. The extracellular polysaccharides were purified by ethanol precipitation, electrodialysis, extraction with quaternary ammonium salts, and gel filtration. These purification steps allowed for the separation and purification of both the extracellular lipopolysaccharide and the extracellular capsular polysaccharide. Purified extracellular capsular polysaccharide and extracellular lipopolysaccharide were co-injected with K. pneumoniae intraperitoneally into mice to determine if either of these substances would produce an effect on the natural course of infection in these animals. These studies showed that only purified extracellular lipopolysaccharide enhanced the virulence of K. pneumoniae when co-injected into mice, and this virulence enhancement correlated with the content of extracellular lipopolysaccharide, but not extracellular capsular polysaccharide in mixtures of these polysaccharides. Saponification of K. pneumoniae serotype 1 extracellular polysaccharides significantly decreased their virulence-enhancing capabilities in mice, further suggesting that extracellular lipopolysaccharide may play a role in these infections.
31
Xu, Junpeng, e Shan-hui Hsu. "Enhancement of Cell Behavior by the Polysaccharide Extract of Arthrospira and Potential Biomedical Applications". Molecules 28, n.º 2 (11 de janeiro de 2023): 732. http://dx.doi.org/10.3390/molecules28020732.
Texto completo da fonteResumo:
Arthrospira is one of the most studied cyanobacteria and has been reported with practical applications. Among the substances derived from Arthrospira, polysaccharides have received relatively less attention than phycocyanins, though they have more abundant structural variations and specific properties. Herein, a new Arthrospira-derived sulfated polysaccharide was explored for its potential bioactive functions. The ability of this sulfated polysaccharide to promote the behavior of neural stem cells (NSCs) in three-dimensional hydrogel was examined for the first time. NSCs encapsulated in the sulfated polysaccharide-containing hydrogel showed better proliferation than the control hydrogel as well as a unique cell clustering behavior, i.e., formation of multicellular spherical clusters (40–60 μm). The sulfated polysaccharide, in an appropriate range of concentration (5 mg/mL), also maintained the stemness of NSCs in hydrogel and facilitated their differentiation. In addition, the potentials of the new sulfated polysaccharide as a coating material and as a component for drug carrier were verified. The sulfated polysaccharide-modified substrate exhibited superhydrophilicity (contact angle ~9) and promoted cell adhesion to the substrate. Composite nanoparticles composed of the sulfated polysaccharide and other differently charged polysaccharides were produced with an average diameter of ~240 nm and estimated drug loading of ~18%. The new Arthrospira-derived sulfated polysaccharide is a promising candidate for cell culture, surface-modification, and drug-delivery applications in the biomedical field.
32
Wang, Bo, Lu Han, Jun-Mei Liu, Jin Zhang, Wen Wang, Bing-Ge Li, Cai-Xia Dong e Chang-Cai Bai. "Lycium Genus Polysaccharide: An Overview of Its Extraction, Structures, Pharmacological Activities and Biological Applications". Separations 9, n.º 8 (30 de julho de 2022): 197. http://dx.doi.org/10.3390/separations9080197.
Texto completo da fonteResumo:
Polysaccharide is considered to be the main active ingredient of the genus Lycium L., which is taken from the dried fruit of the famous Chinese herbal medicine and precious tonic known as wolfberry. Traditional uses include nourishing the liver and kidney and improving eyesight, with widespread use in the clinical practice of traditional Chinese medicine. Many studies have focused on the isolation and identification of the genus Lycium L. polysaccharide and its biological activities. However, the variety of raw materials and the mechanisms of polysaccharides differ. After extraction, the structure and biological activity of the obtained polysaccharides also differ. To date, approximately 58 kinds of polysaccharides have been isolated and purified from the Lycium genus, including water-soluble polysaccharides; homogeneous polysaccharides; pectin polysaccharides; acidic heteropolysaccharides; and arabinogalactans, which are composed of arabinose, glucosamine, galactose, glucose, xylose, mannose, fructose, ribose, galacturonic acid, and glucuronic acid. Pharmacological studies have shown that LBPs exhibit a variety of important biological activities, such as protection of nerves; promotion of reproduction; and anti-inflammatory, hepatoprotective, hypoglycemic, and eyesight-improving activities. The aim this paper is to summarize previous and current references to the isolation process, structural characteristics, and biological activities of the genus Lycium L. polysaccharide. This review will provide a useful reference for further research and application of the genus Lycium L. polysaccharide in the field of functional food and medicine.
33
Silva, Inês M. V., Fernanda Machado, Maria João Moreno, Cláudia Nunes, Manuel A. Coimbra e Filipe Coreta-Gomes. "Polysaccharide Structures and Their Hypocholesterolemic PoTential". Molecules 26, n.º 15 (28 de julho de 2021): 4559. http://dx.doi.org/10.3390/molecules26154559.
Texto completo da fonteResumo:
Several classes of polysaccharides have been described to have hypocholesterolemic potential, namely cholesterol bioaccessibility and bioavailability. This review will highlight the main mechanisms by which polysaccharides are known to affect cholesterol homeostasis at the intestine, namely the effect (i) of polysaccharide viscosity and its influence on cholesterol bioaccessibility; (ii) on bile salt sequestration and its dependence on the structural diversity of polysaccharides; (iii) of bio-transformations of polysaccharides and bile salts by the gut microbiota. Different quantitative structure–hypocholesterolemic activity relationships have been explored depending on the mechanism involved, and these were based on polysaccharide physicochemical properties, such as sugar composition and ramification degree, linkage type, size/molecular weight, and charge. The information gathered will support the rationalization of polysaccharides’ effect on cholesterol homeostasis and highlight predictive rules towards the development of customized hypocholesterolemic functional food.
34
Su, Chunyu, Yutong Chen, Shujing Tian, Chunxiu Lu e Qizhuang Lv. "Research Progress on Emerging Polysaccharide Materials Applied in Tissue Engineering". Polymers 14, n.º 16 (11 de agosto de 2022): 3268. http://dx.doi.org/10.3390/polym14163268.
Texto completo da fonteResumo:
The development and application of polysaccharide materials are popular areas of research. Emerging polysaccharide materials have been widely used in tissue engineering fields such as in skin trauma, bone defects, cartilage repair and arthritis due to their stability, good biocompatibility and reproducibility. This paper reviewed the recent progress of the application of polysaccharide materials in tissue engineering. Firstly, we introduced polysaccharide materials and their derivatives and summarized the physicochemical properties of polysaccharide materials and their application in tissue engineering after modification. Secondly, we introduced the processing methods of polysaccharide materials, including the processing of polysaccharides into amorphous hydrogels, microspheres and membranes. Then, we summarized the application of polysaccharide materials in tissue engineering. Finally, some views on the research and application of polysaccharide materials are presented. The purpose of this review was to summarize the current research progress on polysaccharide materials with special attention paid to the application of polysaccharide materials in tissue engineering.
35
Kanaani, Y. M., A. Adin e Ch Rav-Acha. "Biofilm Interactions in Water Reuse Systems: Adsorption of Polysaccharide to Kaolin". Water Science and Technology 26, n.º 3-4 (1 de agosto de 1992): 673–82. http://dx.doi.org/10.2166/wst.1992.0448.
Texto completo da fonteResumo:
Interactions of biofilms with dissolved and suspended aquatic matter play an important role in many water work technologies. In order to get a better insight into the driving forces for these interactions, the adsorption of polysaccharides to kaolin clay was studied. The linear adsorption coefficients, obtained at various pH levels, were all substantially lower than those obtained in other studies for humic materials(HA) at pH 6 k=60ml/g for polysaccharide, but for HA k=700ml/g. This is explained in light of the higher hydrophobicity of humic materials. The adsorption coefficient for polysaccharides increases with ionic strength, with the addition of calcium ion, and when the pH is reduced. All these phenomena are explained by conformational changes, of the polysaccharide macromolecules, which result in respective changes in its electric charge. These phenomena are also in accord with the results obtained by determination of the micro-electrophoretic mobility of the clay and clay-polysaccharide particles. For instance, at reduced pH levels the enhanced adsorption was accompanied by decreasing of the negative electrophoretic mobility. Both of these results point to a reduced electric density of polysaccharide and clay-polysaccharide particles when the pH is reduced. All these results may also explain the effect of polysaccharides on the clay coagulation-flocculation by alum.
36
Pan, Y. K., Y. H. Han e R. Q. Huang. "Isolation and Purification of Polysaccharides from Litchi Seeds, with an Analysis of in Vitro Hypoglycemic Effect". Acta Alimentaria 49, n.º 4 (7 de novembro de 2020): 365–74. http://dx.doi.org/10.1556/066.2020.49.4.1.
Texto completo da fonteResumo:
Polysaccharides from litchi (Litchi chinensis) seeds were isolated and purified using ion exchange column chromatography. Molecular weight distribution of polysaccharides and monosaccharides were detected. Preliminary structural characterisation of polysaccharides was conducted using infrared, nuclear magnetic, and other spectroscopy techniques in combination with methylation analysis. In vitro cell culture experiments were designed to detect the effects of polysaccharides on cell growth and cellular glucose consumption. We extracted and analysed three polysaccharides from litchi seed. Monosaccharide composition and infrared spectroscopy detection showed that the skeleton structure of polysaccharides consisted of glucose and mannose. Polysaccharides 1 and 2 are similar and have relatively high glucose content (around 70%); polysaccharide 3 has 39.17% glucose only but is rich in arabinose (about 21.03%). In a certain range of use (50~1000 μg ml–1), polysaccharides 1 and 2 have no significant impacts on cell growth, while polysaccharide 3 can promote proliferation to some extent. All three polysaccharides can promote in vitro cellular glucose consumption, especially polysaccharide 3, which shows the strongest promotion, a significant dose effect, and synergistic effect with insulin. The above results highlight important roles of litchi seed polysaccharides in promoting cell growth and validate litchi seed polysaccharides as potential drugs for hypoglycaemia.
37
Cui, Feng-Jie, Li-Sun Qian, Wen-Jing Sun, Jin-Song Zhang, Yan Yang, Na Li, Hai-Ning Zhuang e Di Wu. "Ultrasound-Assisted Extraction of Polysaccharides from Volvariella volvacea: Process Optimization and Structural Characterization". Molecules 23, n.º 7 (13 de julho de 2018): 1706. http://dx.doi.org/10.3390/molecules23071706.
Texto completo da fonteResumo:
The aims of the present study were to optimize the operational parameters to maximize the yield of ultrasound-assisted polysaccharide extraction from Volvariella volvacea (straw mushroom) fruiting bodies by using for the first time one-factor-at-a-time and three-level Box-Behnken factorial designs. A maximum polysaccharide yield of 8.28 ± 0.23% was obtained under the optimized conditions of ultrasound power of 175 W, extraction temperature of 57 °C, extraction time of 33 min, and the ratio of liquid to raw material of 25:1, respectively. Compared to the hot-water extraction, the ultrasound-assistance favored the extraction of polysaccharides from V. volvacea for its higher polysaccharide yield and efficiency. Further preliminary polysaccharide structural characterization indicated that ultrasound treatment affected the monosaccharide compositions and ratios, and molecular weight range of polysaccharides extracted from V. volvacea.
38
Vukojevic, Jelena, Mirjana Stajic, Sonja Duletic-Lausevic e Jasmina Simonic. "Effect of medium pH and cultivation period on mycelial biomass, polysaccharide, and ligninolytic enzyme production by Ganoderma lucidum from Montenegro". Archives of Biological Sciences 58, n.º 3 (2006): 179–82. http://dx.doi.org/10.2298/abs0603179v.
Texto completo da fonteResumo:
The effect of initial medium pH on biomass, extracellular and intracellular polysaccharide, and ligninolytic enzyme production by Ganoderma lucidum was investigated at different pH values after 7 and 14 days of cultivation. Maximal production of biomass was recorded at pH 4.5 and 5.0; maximal production of extracellular polysaccharides at pH 7.0 and 3.0; and maximal production of intracellular polysaccharides at pH 7.0 and 5.5. Ligninolytic enzymes were not produced at any pH of the medium. Maximal biomass production was obtained on the 11th day of cultivation; maximal extracellular polysaccharide production on the 7th day; and maximal intracellular polysaccharide production on the 6th and 10th day of cultivation. .
39
Obukhanych, Tetyana V., e Michel C. Nussenzweig. "T-independent type II immune responses generate memory B cells". Journal of Experimental Medicine 203, n.º 2 (13 de fevereiro de 2006): 305–10. http://dx.doi.org/10.1084/jem.20052036.
Texto completo da fonteResumo:
Unlike T-dependent immune responses against protein antigens, T-independent responses against polysaccharides confer long-lasting humoral immunity in the absence of recall responses and are not known to generate memory B cells. Here we report that polysaccharide antigens elicit memory B cells that are phenotypically distinct from those elicited by protein antigens. Furthermore, memory B cell responses against polysaccharides are regulated by antigen-specific immunoglobulin G antibodies. As the generation and regulation of immunologic memory is central to vaccination, our findings help explain the mode of action of the few existing polysaccharide vaccines and provide a rationale for a wider application of polysaccharide-based strategies in vaccination.
40
Furusawa, Go, Nor Azura Azami e Aik-Hong Teh. "Genes for degradation and utilization of uronic acid-containing polysaccharides of a marine bacterium Catenovulum sp. CCB-QB4". PeerJ 9 (9 de março de 2021): e10929. http://dx.doi.org/10.7717/peerj.10929.
Texto completo da fonteResumo:
Background Oligosaccharides from polysaccharides containing uronic acids are known to have many useful bioactivities. Thus, polysaccharide lyases (PLs) and glycoside hydrolases (GHs) involved in producing the oligosaccharides have attracted interest in both medical and industrial settings. The numerous polysaccharide lyases and glycoside hydrolases involved in producing the oligosaccharides were isolated from soil and marine microorganisms. Our previous report demonstrated that an agar-degrading bacterium, Catenovulum sp. CCB-QB4, isolated from a coastal area of Penang, Malaysia, possessed 183 glycoside hydrolases and 43 polysaccharide lyases in the genome. We expected that the strain might degrade and use uronic acid-containing polysaccharides as a carbon source, indicating that the strain has a potential for a source of novel genes for degrading the polysaccharides. Methods To confirm the expectation, the QB4 cells were cultured in artificial seawater media with uronic acid-containing polysaccharides, namely alginate, pectin (and saturated galacturonate), ulvan, and gellan gum, and the growth was observed. The genes involved in degradation and utilization of uronic acid-containing polysaccharides were explored in the QB4 genome using CAZy analysis and BlastP analysis. Results The QB4 cells were capable of using these polysaccharides as a carbon source, and especially, the cells exhibited a robust growth in the presence of alginate. 28 PLs and 22 GHs related to the degradation of these polysaccharides were found in the QB4 genome based on the CAZy database. Eleven polysaccharide lyases and 16 glycoside hydrolases contained lipobox motif, indicating that these enzymes play an important role in degrading the polysaccharides. Fourteen of 28 polysaccharide lyases were classified into ulvan lyase, and the QB4 genome possessed the most abundant ulvan lyase genes in the CAZy database. Besides, genes involved in uronic acid metabolisms were also present in the genome. These results were consistent with the cell growth. In the pectin metabolic pathway, the strain had genes for three different pathways. However, the growth experiment using saturated galacturonate exhibited that the strain can only use the pathway related to unsaturated galacturonate.
41
Bac, Vo Hoai, Tran Thi Van Anh, Nguyen Thi Mai Phuong, Nguyen Thi Thanh Huong e Le Van Truong. "OPTIMIZED EXTRACTION AND IMMUNOSTIMULATORY EFFECTS OF POLYSACCHARIDES FROM PSEUDERANTHEMUM PALATIFERUM (NEES) RADLK". Vietnam Journal of Biotechnology 16, n.º 2 (17 de dezembro de 2018): 327–35. http://dx.doi.org/10.15625/1811-4989/16/2/13445.
Texto completo da fonteResumo:
Pseuderanthemum palatiferum (Ness) Radlk is a tree native of Vietnam with various use in traditional medicine. It has been used for the treatment of many diseases including wound, colitis, stomach-aches, trauma, high blood pressure, nephritis, diarrhoea. However, the research on effective constituents from P. palatiferum has mainly been focused on small-molecular compounds. Some compounds: flavonoids, phytol, palmitic acid, ß-sitosterol, triterpenoid saponin, stigmasterol and salicylic acid have been detected in leaves. Polysaccharides have attracted great attentions for its benefits to human health. Polysaccharides from natural sources have diverse anti-inflammatory, anticoagulant and wound healing activities. In this study, we extracted and determined the polysaccharide content from the leaves of P. palatiferum plant. The polysaccharide content in P. palatiferum leaves was 8.2% (± 0.65) in dry weight. The appropriate polysaccharide extraction conditions were determined as: 25% ethanol, material/solvent ratio (1g/10ml), extracted temperature of 70°C, extraction time 12 hours. The polysaccharide composition was purified by TCA 10%, with a purity of 77.8% (± 1.19). The immunostimulatory activities of polysaccharide XH were also examined in cyclophosphamide (CY)-induced immunosuppressed mice. Mice treated with polysaccharide XH exhibited increased white blood cell counts (p < 0.05) compared with immunosuppressed mice. These results indicate that polysaccharide XH from P. palatiferum can enhance immune function in CY-induced immunosuppressed mice.
42
Sun, Yanzhen, Xiaodong Jing, Xiaoli Ma, Yinglong Feng e Hao Hu. "Versatile Types of Polysaccharide-Based Drug Delivery Systems: From Strategic Design to Cancer Therapy". International Journal of Molecular Sciences 21, n.º 23 (1 de dezembro de 2020): 9159. http://dx.doi.org/10.3390/ijms21239159.
Texto completo da fonteResumo:
Chemotherapy is still the most direct and effective means of cancer therapy nowadays. The proposal of drug delivery systems (DDSs) has effectively improved many shortcomings of traditional chemotherapy drugs. The technical support of DDSs lies in their excellent material properties. Polysaccharides include a series of natural polymers, such as chitosan, hyaluronic acid, and alginic acid. These polysaccharides have good biocompatibility and degradability, and they are easily chemical modified. Therefore, polysaccharides are ideal candidate materials to construct DDSs, and their clinical application prospects have been favored by researchers. On the basis of versatile types of polysaccharides, this review elaborates their applications from strategic design to cancer therapy. The construction and modification methods of polysaccharide-based DDSs are specifically explained, and the latest research progress of polysaccharide-based DDSs in cancer therapy are also summarized. The purpose of this review is to provide a reference for the design and preparation of polysaccharide-based DDSs with excellent performance.
43
Arnosti, C., M. Wietz, T. Brinkhoff, J. H. Hehemann, D. Probandt, L. Zeugner e R. Amann. "The Biogeochemistry of Marine Polysaccharides: Sources, Inventories, and Bacterial Drivers of the Carbohydrate Cycle". Annual Review of Marine Science 13, n.º 1 (3 de janeiro de 2021): 81–108. http://dx.doi.org/10.1146/annurev-marine-032020-012810.
Texto completo da fonteResumo:
Polysaccharides are major components of macroalgal and phytoplankton biomass and constitute a large fraction of the organic matter produced and degraded in the ocean. Until recently, however, our knowledge of marine polysaccharides was limited due to their great structural complexity, the correspondingly complicated enzymatic machinery used by microbial communities to degrade them, and a lack of readily applied means to isolate andcharacterize polysaccharides in detail. Advances in carbohydrate chemistry, bioinformatics, molecular ecology, and microbiology have led to new insights into the structures of polysaccharides, the means by which they are degraded by bacteria, and the ecology of polysaccharide production and decomposition. Here, we survey current knowledge, discuss recent advances, and present a new conceptual model linking polysaccharide structural complexity and abundance to microbially driven mechanisms of polysaccharide processing. We conclude by highlighting specific future research foci that will shed light on this central but poorly characterized component of the marine carbon cycle.
44
Qian, Lijuan, Mengxiang Du, Xiaoyan Yang, Qian Wang, Shengwei Huang, Yuhan Ma e Yujun Sun. "Microanalysis Characterization and Immunomodulatory Effect for Selenium-Enriched Polysaccharide from Morchella esculenta (L.) Pers." Molecules 28, n.º 7 (23 de março de 2023): 2885. http://dx.doi.org/10.3390/molecules28072885.
Texto completo da fonteResumo:
Morchella esculenta (L.) Pers., referred to as Morel, is a medicinal and edible homologous fungus, which contains many bioactive substances. In Morel, polysaccharides are the most abundant and have various bioactivities. In the present work, two novel polysaccharides, Se-MPS and MPS, were prepared and purified from selenium-enriched (Se-enriched) and common Morel mycelia, respectively, and their structural and immunomodulatory properties were evaluated. The results show that Se-enriched treatment significantly changed the polysaccharides’ chemical composition, molecular weight, and sugar chain configuration. In addition, the Se-enriched treatment also improved the polysaccharides’ fragmentation and thermal stability. Importantly, Se-enriched Morel polysaccharide (Se-MPS) could significantly enhance phagocytosis of RAW 264.7 macrophage cells and, remarkably, activate their immune response via activating the TLR4-TRAF6-MAPKs-NF-κB cascade signaling pathway, finally exerting an immunomodulatory function. Based on these findings, selenium-enriched Morel polysaccharide appears to have more potential for development and utilization in functional foods or medicines than ordinary Morel polysaccharide.
45
Yan, Tongmeng, Kua Hu, Fei Ren e Zhihong Jiang. "LC-MS/MS Profiling of Post-Transcriptional Modifications in Ginseng tRNA Purified by a Polysaccharase-Aided Extraction Method". Biomolecules 10, n.º 4 (17 de abril de 2020): 621. http://dx.doi.org/10.3390/biom10040621.
Texto completo da fonteResumo:
Transfer RNAs (tRNAs) are the most heavily modified RNA species in life entities. Post-transcriptional modifications severely impact the structure and function of tRNAs. To date, hundreds of modifications have been identified in tRNAs, mainly from microorganisms and animals. However, tRNAs in plant roots or tubers that have been widely used for food and medical purpose for centuries are rarely studied because isolation of RNA from plants still remains a challenge. In this paper, a polysaccharase-aided RNA isolation (PARI) method for extraction of high-quality RNA from plants containing large quantities of polysaccharides is developed. This method presents a new strategy of “digesting” polysaccharides that is completely different from the conventional method of “dissolving” the contaminants. By using this method, RNA of high integrity and purity were successfully extracted from ginseng roots because polysaccharide contaminations were removed efficiently with α-amylase digestion. Ginseng tRNAs were first sequenced by NGS and a total of 41 iso acceptors were identified. ChloroplastictRNAGly(GCC) in ginseng root was purified and four modified nucleosides, including m7G, D, T, and Ψ, were identified by LC-MS/MS. The results also revealed that the m7G occurs at a novel position 18, which may be related to the deformation of D-loop. PARI is the first enzyme-assisted technique for RNA isolation from plants, which could fundamentally solve the problem of polysaccharide contaminations. By using the PARI method, more individual tRNAs could be isolated easily from polysaccharide-rich plant tissues, which would have a positive impact on the feasibility of research on structure and function of tRNA in plants.
46
Wang, Bo, Haiyan Tian e Dong Xiang. "Stabilizing the Oil-in-Water Emulsions Using the Mixtures of Dendrobium Officinale Polysaccharides and Gum Arabic or Propylene Glycol Alginate". Molecules 25, n.º 3 (10 de fevereiro de 2020): 759. http://dx.doi.org/10.3390/molecules25030759.
Texto completo da fonteResumo:
Coconut oil-in-water emulsions were prepared using three polysaccharides: Dendrobium officinale polysaccharide (DOP), propylene glycol alginate (PGA), gum arabic (GA) and their polysaccharide complexes as emulsifiers. The effects of the ratio of the compounded polysaccharides on their apparent viscosity and interfacial activity were explored in this study. The average particle size, zeta potential, microstructure, rheological properties, and physical stability of the emulsions prepared with different compound-polysaccharides were studied. The results showed that mainly DOP contributed to the apparent viscosity of the compound-polysaccharide, while the interfacial activity and zeta potential were mainly influenced by PGA or GA. Emulsions prepared with compound-polysaccharides exhibited smaller average particle sizes, and microscopic observations showed smaller droplets and less droplet aggregation. In addition, the stability analysis of emulsions by a dispersion analyzer LUMiSizer showed that the emulsion prepared by compounding polysaccharides had better physical stability. Finally, all of the above experimental results showed that the emulsions prepared by PGA:DOP = 2:8 (total concentration = 1.5 wt%) and 2.0% GA + 1.5% DOP were the most stable.
47
Sun, Ying, Xiaoli Ma e Hao Hu. "Marine Polysaccharides as a Versatile Biomass for the Construction of Nano Drug Delivery Systems". Marine Drugs 19, n.º 6 (16 de junho de 2021): 345. http://dx.doi.org/10.3390/md19060345.
Texto completo da fonteResumo:
Marine biomass is a treasure trove of materials. Marine polysaccharides have the characteristics of biocompatibility, biodegradability, non-toxicity, low cost, and abundance. An enormous variety of polysaccharides can be extracted from marine organisms such as algae, crustaceans, and microorganisms. The most studied marine polysaccharides include chitin, chitosan, alginates, hyaluronic acid, fucoidan, carrageenan, agarose, and Ulva. Marine polysaccharides have a wide range of applications in the field of biomedical materials, such as drug delivery, tissue engineering, wound dressings, and sensors. The drug delivery system (DDS) can comprehensively control the distribution of drugs in the organism in space, time, and dosage, thereby increasing the utilization efficiency of drugs, reducing costs, and reducing toxic side effects. The nano-drug delivery system (NDDS), due to its small size, can function at the subcellular level in vivo. The marine polysaccharide-based DDS combines the advantages of polysaccharide materials and nanotechnology, and is suitable as a carrier for different pharmaceutical preparations. This review summarizes the advantages and drawbacks of using marine polysaccharides to construct the NDDS and describes the preparation methods and modification strategies of marine polysaccharide-based nanocarriers.
48
Zhao, Qiang, Jie Qin, Hairong Wang, Jingyu Wang e Xueming Zhang. "Effects of different extraction methods on the properties of pine cone polysaccharides from Pinus koraiensis". BioResources 14, n.º 4 (31 de outubro de 2019): 9945–56. http://dx.doi.org/10.15376/biores.14.4.9945-9956.
Texto completo da fonteResumo:
In order to realize the resource utilization of the Pinus koraiensis pine cone, the polysaccharides were obtained by a traditional hot water extraction process, and the optimal extraction process was confirmed. The effects of a traditional hot water, alkali, and ultrasound assisted extraction on the yield and properties of polysaccharides were studied. The structure, monosaccharide composition, and content of polysaccharides obtained by different extraction methods were analyzed by means of Fourier infrared chromatography and liquid chromatography. Effects of polysaccharides extracted by different methods on the antimicrobial activity of Staphylococcus aureus and Escherichia coli were studied. The scavenging effect of DPPH free radicals were also examined. The optimum condition of the hot water extraction was identified as an extraction temperature of 100 °C, a ratio of material to water at 1:16 (w/v), an extraction time of 4 h, and a yield of polysaccharide at 10.2%. In comparison, the yield of the pine cone polysaccharide was improved significantly to 29.1% by using NaOH solution extraction method. The FTIR spectra of polysaccharides showed that the samples possessed the typical chemical structure of a polysaccharide.
49
Cumpstey, Ian. "Chemical Modification of Polysaccharides". ISRN Organic Chemistry 2013 (10 de setembro de 2013): 1–27. http://dx.doi.org/10.1155/2013/417672.
Texto completo da fonteResumo:
This review covers methods for modifying the structures of polysaccharides. The introduction of hydrophobic, acidic, basic, or other functionality into polysaccharide structures can alter the properties of materials based on these substances. The development of chemical methods to achieve this aim is an ongoing area of research that is expected to become more important as the emphasis on using renewable starting materials and sustainable processes increases in the future. The methods covered in this review include ester and ether formation using saccharide oxygen nucleophiles, including enzymatic reactions and aspects of regioselectivity; the introduction of heteroatomic nucleophiles into polysaccharide chains; the oxidation of polysaccharides, including oxidative glycol cleavage, chemical oxidation of primary alcohols to carboxylic acids, and enzymatic oxidation of primary alcohols to aldehydes; reactions of uronic-acid-based polysaccharides; nucleophilic reactions of the amines of chitosan; and the formation of unsaturated polysaccharide derivatives.
50
Illanes-Bordomás, Carlos, Mariana Landin e Carlos A. García-González. "Aerogels as Carriers for Oral Administration of Drugs: An Approach towards Colonic Delivery". Pharmaceutics 15, n.º 11 (17 de novembro de 2023): 2639. http://dx.doi.org/10.3390/pharmaceutics15112639.
Texto completo da fonteResumo:
Polysaccharide aerogels have emerged as a highly promising technology in the field of oral drug delivery. These nanoporous, ultralight materials, derived from natural polysaccharides such as cellulose, starch, or chitin, have significant potential in colonic drug delivery due to their unique properties. The particular degradability of polysaccharide-based materials by the colonic microbiota makes them attractive to produce systems to load, protect, and release drugs in a controlled manner, with the capability to precisely target the colon. This would allow the local treatment of gastrointestinal pathologies such as colon cancer or inflammatory bowel diseases. Despite their great potential, these applications of polysaccharide aerogels have not been widely explored. This review aims to consolidate the available knowledge on the use of polysaccharides for oral drug delivery and their performance, the production methods for polysaccharide-based aerogels, the drug loading possibilities, and the capacity of these nanostructured systems to target colonic regions.