Polysaccharide Solutions Research Articles

Antibacterial activity of Osmunda japonica (Thunb) polysaccharides and its effect on tomato quality maintenance during storage

AbstractTomatoes are rich in nutrients, yet they have a short shelf life and are prone to decay due to bacterial invasion. Polysaccharides extracted from Osmunda japonica (Thunb) were briefly characterised. The inhibitory effect of polysaccharides on nine kinds of common spoilage and pathogenic bacteria in tomatoes stored postharvest was studied, and the polysaccharides had broad‐spectrum antibacterial and antifungal activities against many tested strains. The minimum inhibitory concentrations (MICs) and the minimum bactericidal (fungicidal) concentrations (MBCs) were determined, and the lowest MBC against Bacillus cereus was 0.15 g L−1. Various concentrations of an O. japonica (Thunb) polysaccharide (OP) solution were sprayed onto ordinary preservation paper, which then distinctly maintained tomato freshness. OP delayed vitamin C (VC) and titratable acid decreases and increased respiratory intensity in a dose‐dependent manner, reducing malondialdehyde accumulation. The tomatoes could be stored for 30 day at 25 ± 1 °C. OP has potential as a safe, nontoxic natural plant preservative.

Fabrication and Characterization of Polysaccharide Composite Films from Polyion Complex Particles.

Biomaterials made of natural polysaccharides have attracted much attention due to the fact of their excellent properties, such as high biocompatibility and biodegradability, and their specific biological functions based on their chemical structures. This study demonstrates that polysaccharide composite films can be fabricated from polyion complexes (PICs) with their particles used as building components. Dispersion of PIC particles prepared by mixing, centrifugation, and re-dispersion of dilute solutions of cationic and anionic polysaccharides were cast, dried, and formed into films several micrometers thick. These films were homogenous and water insoluble. It was revealed that the component anionic polysaccharides affected the film’s properties such as the swelling behavior and mechanical characteristics. Adhesion of NIH3T3 cells (integrin: high, CD44: lack or weak) and A549 cells (integrin: high, CD44: high) to the composite films were examined. Both NIH3T3 and A549 cells adhered to heparin/chitosan (HEP/CHI) film because HEP has an affinity for integrin through fibronectin. However, A549 cells adhered to chondroitin sulfate (CS)/CHI and hyaluronic acid (HYA)/CHI films, whereas NIH3T3 cells did not, because both CS and HYA have affinity for CD44. These results indicated that the biological functions of anionic polysaccharides were maintained on the surface of the composite films. It was also possible to fabricate films composed of three kinds of polysaccharides: one cationic polysaccharide and two kinds of anionic polysaccharides. These results show that the properties of films composed of three kinds of polysaccharides may be controllable depending on the anionic polysaccharide composition rates.

Flocculation of Titanium Dioxide with Functionalized Citrus Pectin

Modified polysaccharides were prepared by the reaction of citrus pectin with a cationic monomer, (1,2-epoxypropyl)triethylammonium chloride, in alkaline medium and under the action of microwave radiation in the reactor system microwave–ultrasonic–UV-induced synthesis. Organic hybrids were prepared by mixing aqueous solutions of natural polysaccharides (pectin and modified pectin with chitosan) under ambient conditions in 1 : 1 ratio. The influence of the concentration of citrus pectin, its modified samples, chitosan, and their organic hybrids on the flocculating properties was studied for a model disperse system, a suspension of titanium dioxide in water and aqueous salt solutions, under the conditions of free (unrestricted) sedimentation. The influence of the ionic strength on the conformational state of polysaccharide macromolecules and on the aggregation of titanium dioxide particles was analyzed.

Response of photonic crystal hydrogels to carbohydrate and polyhydroxy alcohols

Inverse opal hydrogel films composed of hydroxyethyl 2-methacrylate and phenylboronic acid (IOHGHEMA+3APBA) were prepared by a convenient ultrasonic-induced self-assembly method. The IOHGHEMA+3APBA films had brilliant blue-violet color when they were immersed in deionized water and reached swelling equilibrium. The IOHGHEMA+3APBA films were used as sensors to detect chemicals with similar structures. When the IOHGHEMA+3APBA films were in contact with different monosaccharide, polysaccharide or polyhydric alcohol solutions, their reflection peaks maxima (λmax) shifted over the entire visible wavelength range (520 to 780 nm). The red shift of λmax was related to the number of effective hydroxyl groups and the molecular size of the detected molecules. Thus isomers or organic compounds with similar structures or properties may induce different λmax shifts of the IOHGHEMA+3APBA films.

Escherichia coli O176 LPS structure and dynamics: A NMR spectroscopy and MD simulation study.

A lipopolysaccharide (LPS) molecule is a key component of the bacterial outer membrane used to protect the bacterium and to interact with the environment. To gain insight into its function, the study of the LPS conformation and dynamics at the molecular and cellular levels is necessary, but these highly diverse and dynamic membrane-LPS systems are difficult to study. In this work, by using NMR spectroscopy and molecular dynamics (MD) simulations, we determined the conformational preferences of an E. coli O176 O-antigen polysaccharide at the atomic level. Moreover, we analyzed the use of non-uniform sampling (NUS) for the acquisition of high dynamic range spectra, like 1H,1H-NOESY NMR experiments. A comparison of the effective transglycosidic distances derived from conventional uniformly sampled and NUS 1H,1H-NOESY data showed high similarity under equal measuring time conditions. Furthermore, the experimentally derived internuclear distances of the O-antigen polysaccharide with ten repeating units (RUs) showed very good agreement to those calculated from the MD simulations of the same O-antigen polysaccharide in solution. Analysis of the LPS bilayer simulations with five and with ten RUs revealed that, although similar with respect to populated states in solution, the O-antigen in LPS bilayers had more extended chains as a result of spatial limitations due to close packing. Additional MD simulations of O-antigen polysaccharides from E. coli O6 (branched repeating unit) and O91 (negatively charged linear repeating unit) in solution and LPS bilayers were performed and compared to those of O176 (linear polymer). For all three O-antigens, the ensemble of structures present for the polysaccharides in solution were consistent with the results from their 1H,1H-NOESY experiments. In addition, the similarities between the O-antigen on its own and as a constituent of the full LPS in bilayer environment makes it possible to realistically describe the LPS conformation and dynamics from the MD simulations.

Економічна ефективність зберігання плодів вишні за обробки полісахаридними композиціями

The article shows the economic efficiency of storage of cherry fruits, pre-treated with polysaccharide compositions: a solution of chitosan, sodium alginate before storage. As the demand for the production of fruit and berry products causes an increase in fruit production and the emergence of new fruit and berry farms, so the problem of cooling and storage of fruit becomes relevant. The aim of the research was to determine the economic efficiency of cherry fruits, pre-treated with polysaccharide compositions after storage. The research was conducted during 2016−2019 on the basis of the pomology research station named after L.P. Symyrenko IS NAAS with cherry fruits of varieties Alpha and Memory Artemenko. The cherry fruits were sprayed with a solution of chitosan with salicylic acid the day before harvest, then removed at the consumer stage of ripeness and placed in storage boxes at a temperature of 1±0 , 5°C and relative humidity of 95 ± 1%. Raw fruits were taken as control. Selected cherry fruits were washed with water and immersed in 5% sodium alginate solutions according to the options: without treatment (control) and treated with sodium alginate solutions. Pre-treatment with solutions of chitosan with salicylic acid, allowed to obtain a higher yield of marketable products 92 , 3−93%, for treatment of cherries with a solution of sodium alginate −91 , 3−92 , 4%. Which makes it possible to obtain a higher yield of 7 , 8−8 , 7% and 5 , 6−6 , 8% of marketable products, compared to unprocessed fruits. Pre-treatment of cherry fruits before storage with solutions of polysaccharides: chitosan and sodium alginate, made it possible to obtain a profit of 287,03−311,23 thousand UAH. at the level of profitability of 16,7−18,1%

Nanoscaled Polysaccharides in Solution: Scaling Laws of Hyaluronan

Nanoscaled Polysaccharides in Solution: Scaling Laws of Hyaluronan

Physico-chemical characteristics of the sulfated polysaccharides of the red microalgae Dixoniella grisea and Porphyridium aerugineum

The sulfated polysaccharides of red microalgae have attracted increasing attention in recent years due to their unique rheological and bioactivities. Todate, most studies are devoted to the polysaccharide of the marine species Porphyridium sp., with limited information about that of the brackish water- Dixoniella grisea and the freshwater- Porphyridium aerugineum. We therefore conducted a comparative study of the two less explored sulfated polysaccharides, emphasizing their similarities and differences in composition, physical properties and biocompatibility. Both polysaccharides were found to be composed of 6–8 monosaccharides, predominantly xylose. Sulfur content was 0.8% for P. aerugineum and 1.6% for D. grisea. Solutions of both polysaccharides were highly viscous and exhibited shear thinning and weak gel behavior. Both were found to be stable in an alkaline environment, whereas in an acidic environment the viscosity of the polysaccharide of the brackish water species increased while that of the freshwater species decreased. Both exhibited a similar morphology, having a porous fibrous structure with a rough amorphous surface. By complementing previous studies on the Porphyridium sp. polysaccharide, we have established a sound basis for elucidating the structure/function relationships that in turn, will promote the development of innovative applications for the biotech industries for pharmaceutics, food and drug-delivery.

Wasted Ganoderma tsugae Derived Chitosans for Smear Layer Removal in Endodontic Treatment

The objective of this study is to investigate the synergistic effects of acid etching and metal-ion chelation in dental smear layer removal using wasted Ganoderma tsugae derived chitosans. The wasted Ganoderma tsugae fruiting body was used to prepare both acid-soluble fungal chitosan (FCS) and alkali-soluble polysaccharide (ASP). To explore the effective irrigant concentration for smear layer removal, a chelating effect on ferrous ions was conducted. Specimens of various concentrations of EDTA, citric acid, and polysaccharide solutions were reacted with FerroZine™ then the absorbance was examined at 562 nm by a UV-visible spectrophotometer to calculate their metal chelating capability. Twenty extracted premolars were instrumented and individually soaked in the solutions of 15 wt% EDTA, 10 wt% citric acid, 0.04 wt% ASP, 0.04 wt% FCS, and normal saline were randomly divided into five groups (N=4). Next, each tooth was cleaved longitudinally and examined by scanning electron microscopy (SEM) to assay the effectiveness of smear layer removal. The chelating capability for EDTA, FCS, and ASP showed no significant difference over the concentration of 0.04 wt% (p > 0.05). The SEM results showed that 0.04 wt% FCS solution was effective in smear layer removal along the canal wall. These results indicated that Ganoderma tsuage derived FCS in acid solutions could be a potential alternative as a root canal irrigant solution due to its synergistic effect.

Thermosensitive polysaccharide particles for pulmonary drug delivery

In the present study, we have prepared drug carriers for pulmonary administration: temperature-responsive polysaccharide particles prepared through an emulsion formation and a subsequent sol-gel transition of polysaccharides. The particles are obtained by the cooling of w/o (water-in-oil) emulsions prepared from an aqueous polysaccharide solution and a surfactant-dissolving organic solvent. We found that highly stable s/o (solid-in-oil) suspensions were formed regardless of HLB value, structure, and composition of the surfactants when high-molecular-weight surfactants were used. There are two possible important factors affecting the formation of spherical κ-carrageenan particles: (1) the formation of physically crosslinked domains inside the particle by means of the increase of concentrations of polysaccharides and cations and (2) the formation of a stable solid-liquid interfaces by using high-molecular-weight surfactants. We obtained stable polysaccharide particles with dimpled surfaces. As a result of the in vitro aerosol dispersion performance of the κ-carrageenan particles with the cascade impactor, we identified the characteristic delivery behavior of κ-carrageenan particles: the κ-carrageenan particles delivered more to the alveoli than to the pharynx and bronchi, despite their high density. The present study shows that the “dimpled” κ-carrageenan particles can likely stay in the alveoli so that high therapeutic effects will likely occur in pulmonary administration.

Selenium nanoparticles fabricated in laminarin polysaccharides solutions exert their cytotoxicities in HepG2 cells by inhibiting autophagy and promoting apoptosis

Selenium nanoparticles (SeNPs) have been attracting increasing attention as potential cancer therapeutic agents. In the present study, laminarin polysaccharides (LP) decorated selenium nanoparticles (LP-SeNPs) with an average diameter of ca. 60 nm were synthesized. Transmission electron microscope (TEM), laser particle analyzer, UV–visible spectrometer and Energy dispersive X-ray (EDX) spectrometer were applied to characterize the prepared SeNPs. The cytotoxicity, apoptosis, and autophagy were examined using a series of cellular assays. The results revealed that LP-SeNPs exhibited cytotoxicity against HepG2 cells with IC50 value was 23.4 ± 2.7 μM. After cells were treated with various concentrations of LP-SeNPs (10, 20 and 40 μM) for 24h, the total apoptosis rate increased to 17.4 ± 1.6, 20.9 ± 1.3 and 30.9 ± 1.2%, respectively. Additionally, treatment of LP-SeNPs increased the expression of Bax and cleaved caspase-9 but decreased the level of Bcl-2. This suggested that LP-SeNPs induced mitochondria-mediated apoptosis. Further, exposure of cells to LP-SeNPs for 12 h induced the upregulation of LC3-II and p62. Treatment of chloroquine (CQ), the inhibitors of the autophagosome, resulted in further accumulation of p62 and LC3-II. These results demonstrated that LP-SeNPs induced the activation of early autophagy, but blocked the late phase of autophagy. Inhibition of late phase of autophagy resulted in the damaged organelles cannot be cleared and aggravating apoptosis. In conclusion, these results indicated that LP-SeNPs exerted its cytotoxicity in HepG2 cells by inhibiting autophagy and inducing apoptosis.

Phenolic compounds mediate aggregation of water-soluble polysaccharides and change their rheological properties: Effect of different phenolic compounds

Phenolic compounds are known to bind non-covalently with water-soluble polysaccharides, but the impact of this interaction on the polysaccharides has received little attention. In this study, we examined the impact of polysaccharide-phenolic complexation on the physico-chemical properties of oat β-glucans, guar galactomannan and xanthan mannoglucuronoglucan. These polysaccharides were complexed with model phenolic compounds. Particle size distribution, water mobility and rheological properties (flow behavior and flow consistency indices) were measured on the resulting solutions. We observed colloidal aggregation mediated by phenolic compounds leading to significant changes of the polysaccharides’ rheological properties, in particular a decrease of the pseudo-plastic behavior of the polysaccharides solutions.

The rheological properties of differentially extracted polysaccharides from potatoes peels

The effects of concentration, temperature, pH, and salt ion concentration on the apparent viscosity of potato peel (PP) polysaccharide solutions were studied. The results showed that the PP polysaccharides exhibited the characteristics of “non-Newtonian fluid”. The apparent viscosity of the PP polysaccharides decreased under acidic, alkaline conditions, and with the increasing temperature. At the increasing concentration of PAC with the addition of four ion concentrations, the apparent viscosity was decreased gradually. The apparent viscosity of PAL increased with four ion concentrations, while that of PW increased initially with the rising concentration of Na+, Mg2+, and K+ and then decreased. Addition of Ca2+ lowered the apparent viscosity initially which was followed by further increase. The results of dynamic rheological experiment showed that the loss modulus G″ of PP polysaccharide was higher than the storage modulus G′ at lower frequencies, and vice versa at higher frequencies. With the increasing concentration of PP polysaccharides, the values of the intersection of G′ and G″ were lowered. The results showed that the rheological properties of PP polysaccharide solutions were affected by concentration, temperature, pH, and salt ions.

Alginate-based hydrogels prepared via ionic gelation: An experimental design approach to predict the crosslinking degree

Alginate-based hydrogels can be obtained by the simple addition of bivalent ions to aqueous polysaccharide solutions without the use of toxic chemicals; however, the hydrogels prepared by this way result inhomogeneous and irreproducible due to the extremely fast crosslinking reaction. To overcome such limitations, in the present work a novel preparation approach is proposed and optimized; the method is based on the use of agar moulds rich of bivalent ions as diffusing system to modulate the release of Ca2+, Sr2+, and Ba2+ cations in order to guarantee a better control of the crosslinking process. A full factorial experimental design was applied to assess the effects and the mutual interactions of three selected parameters (sodium alginate concentration, crosslinking agent concentration within the agar moulds, crosslinking time) on the gelation process. The swelling and mechanical properties of the prepared hydrogels were investigated both in deionized water and in a saline environment; furthermore, the hydrogels were characterized by means of thermogravimetric analysis and field-emission scanning electron microscopy. The obtained results demonstrated that both the experimental variables and the environmental conditions have a significant influence on the structure and the performances of the resulting hydrogels. In particular, the use of high polymer concentration and crosslinking agent amount leads to strong hydrogels corresponding to a superior crosslinking degree; more in detail, Ba2+ ions show a great affinity for alginate leading to the hydrogels with the highest mechanical properties. Moreover, the ion-exchange occurring in saline environment seems to strongly reduce the effective crosslinking degree of alginate hydrogels with a consequential loss of mechanical properties and stability. The collected data were finally elaborated through statistical analysis combined with response surface methodology to develop theoretical models successfully able to correlate the crosslinking degree to the experimental conditions, thus opening the way of designing and fabricating alginate-based hydrogels with tailored morphology and mechanical properties.

Shear induced molecular changes of exopolysaccharides from lactic acid bacteria

Exopolysaccharide (EPS) producing lactic acid bacteria are known for their positive effect on the texture of fermented dairy products, with their high water binding capacity causing changes in rheology and syneresis reduction. During manufacture, product texture is affected by shearing with an unknown impact on the properties of the EPS. By subjecting aqueous solutions of viscosity enhancing EPS from Streptococcus thermophilus DGCC7710 or dextran to defined shear treatments with a Microfluidizer, a cell disruption system or a toothed ring dispersion unit to apply different energy input, we investigated macromolecular properties and the behaviour in solution. Despite the breakage of covalent bonds, spectroscopic NMR analyses revealed that repeating unit structure remained unchanged, whereas changes in macromolecular properties such as intrinsic viscosity, hydrodynamic volume, and molecular mass strongly depended on energy input. The decrease of the dynamic viscosity of the polysaccharide solutions was significantly related to the observed decrease in molecular mass, and the impact of the EPS on technofunctional properties such as contribution to gel stiffness during acid gel formation was also affected. The results therefore indicate that mechanical energy input through shearing should be considered because product texture may be altered as a consequence of a mechanical breakdown of EPS molecules.

Helical polysaccharides

AbstractIn analogy to polypeptides and polynucleotides, polysaccharides tend to form helical secondary structures, as well as higher hierarchical assemblies. Nevertheless, the conformation of polysaccharides in solution remains in most cases elusive due to their intrinsic complexity and lack of analytical techniques. In this review, we discuss the different helical shapes adopted by polysaccharides, with particular focus on how the helical character is exploited to form supramolecular assemblies, such as inclusion complexes with linear guest molecules and co‐helices with polynucleotide strands. Several methodologies are used to tune the polysaccharides conformation, ranging from ion‐mediated coil‐helix transition to chemical synthesis of well‐defined compounds with specific modifications. The latter provides ideal tailor‐made probes for structural studies, with the aim to correlate their three‐dimensional structure and the macroscopic properties. Applications of oligosaccharides with defined shapes in molecular recognition and catalysis are envisioned.

Palladium Based-Polysaccharide Hydrogels as Catalysts in the Suzuki Cross-Coupling Reaction

A simple PdCl2(TPPTS)2 complex was successfully heterogenized in polysaccharide hydrogel beads by using two different methods: (1) dropping the complex and polysaccharide solution into aqueous or ethanol solution of 0.5 M calcium chloride, and (2) dropping the complex and polysaccharide solution into an aqueous solution of chitosan (C). FTIR analyses of the different beads revealed that the complex was heterogenized via interactions between the sulfonate group on the TPPTS and the hydroxyl groups on the polysaccharides. Additionally, the effects of preparation procedure and polysaccharide type on catalytic performance of the formed heterogeneous catalysts in Suzuki cross-coupling was also tested. It was found that the palladium-based hydrogels, which were prepared by the interactions of two polysaccharides, iota carageenan (I) and C, were more active and stable than those that precipitated in the CaCl2 solution. In addition, the I-C-PdCl2(TPPTS)2 heterogeneous catalyst could be easily recycled with minor loss of activity. Moreover, the conversion rates of all heterogeneous systems employed with iodobenzene and phenylboronic acid were higher than those of their homogeneous analogues, a finding that is probably due to the presence of water, which accelerates the reaction, in the hydrogels. At last, SEM–EDS analysis of the hydrogels showed that the complex was immobilized in the hydrogels and that the I-C-PdCl2(TPPTS)2 beads were less condense than the beads that were produced with I-PdCl2(TPPTS)2 in CaCl2 solution, which can explain the higher performance of the former.

Chitosan/glycosaminoglycan scaffolds for skin reparation

Burns and chronic wounds, often related to chronic diseases (as diabetes and cancer), are challenging lesions, difficult to heal. The prompt and full reconstitution of a functional skin is at the basis of the development of biopolymer-based scaffolds, representing a 3D substrate mimicking the dermal extracellular matrix. Aim of the work was to develop scaffolds intended for skin regeneration, according to: fabrication by electrospinning from aqueous polysaccharide solutions; prompt and easy treatment to obtain scaffolds insoluble in aqueous fluids; best performance in supporting wound healing. Three formulations were tested, based on chitosan (CH) and pullulan (P), associated with glycosaminoglycans (chondroitin sulfate - CS or hyaluronic acid – HA). A multidisciplinary approach has been used: chemico-physical characterization and preclinical evaluation allowed to obtain integrated information. This supports that CS gives distinctive properties and optimal features to the scaffold structure for promoting cell proliferation leading tissue reparation towards a complete skin restore.

Effects and mechanism of free amino acids on browning in the processing of black garlic.

Black garlic is produced by heating raw garlic at a high temperature for a long time without any additives. The thermal processing induces many chemical reactions, such as the Maillard reaction, which causes the color change from white to dark brown. Garlic contains a variety of amino acids, and the effect of each amino acid on browning is not fully understood. This work investigated the effect and mechanism of free amino acids on the browning of black garlic using model solutions containing garlic neutral polysaccharide, hydrolyzed garlic neutral polysaccharide, fructose, and free amino acids. A significant increase in reducing sugar was detected when garlic neutral polysaccharide was heated with glycine. The browning intensity of garlic neutral polysaccharide-glycine model solution was obviously higher after heating at 80 °C compared with that of garlic neutral polysaccharide solution. The model solution containing histidine had the greatest browning degree. The histidine model has a stable pH value, and almost no 5-hydroxymethylfurfural (5-HMF) was detected. Amino acid can promote the breaking of the garlic neutral polysaccharide chain and can react with the fructose generated to form browning. Histidine has the greatest effect on the browning, because histidine could eliminate the inhibiting effect of organic acid on Maillard reaction due to the buffer ability, and histidine had high reactivity in the late stage of Maillard reaction. © 2019 Society of Chemical Industry.

Removal of cell wall polysaccharide in pneumococcal capsular polysaccharides by selective degradation via deamination

Pneumococcal cell wall polysaccharide (C–PS), a contaminant in pneumococcal capsular polysaccharide (Pn-PS) vaccines is degraded by mild deamination of the 4-amino-2-acetamido-2,4,6-tri-deoxy-galactose (AAT) in C–PS, which was carried out by addition of 5% aqueous sodium nitrite to a solution of polysaccharide in 5% aqueous acetic acid. Glycosidic linkage and functional groups such as O-acetates, phosphodiesters, and pyruvates were preserved under the conditions. The small fragments from degraded C–PS were removed by ultrafiltration or dialysis to provide essentially C–PS free Pn-PS. Because of the presence of AAT in its structure the deamination is not suitable for the purification of type 1 Pn-PS. Meanwhile, the mass and NMR spectroscopic analysis on the deamination products suggests that both type 1 Pn-PS and C–PS degraded following a major pathway of 5,4-hydride shift, cleavage of AAT O5-C1 bond, C1 hemiacetal formation, and its hydrolysis to release neighboring GalA- in type 1 Pn-PS and GalNAc(6-O-PCho)- in C–PS.