scholarly journals Biochemical Degradation of Chitosan over Immobilized Cellulase and Supported Fenton Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 604
Author(s):  
Huawei Geng ◽  
Zonggang Mou ◽  
Ziyong Liu ◽  
Fuli Li ◽  
Cheng Yang
Keyword(s):  
Molecular Structure ◽  
Industrial Production ◽  
Degree Of Polymerization ◽  
Lower Degree ◽  
Polymerization Degree ◽  
Chitosan Oligosaccharides ◽  
Low Degree ◽  
Immobilized Cellulase ◽  
Biochemical Degradation ◽  
Controllable Degradation

This paper describes the application of Fe-MCM-48 (Mobil Composition of Matter No.48) and cellulase-MCM-48 catalysts for the depolymerization of chitosan. The results show that H2O2 is a good oxidant for the depolymerization of chitosan in the presence of Fe-MCM-48. The average polymerization degree of the product decreased to 6.1, and decreased to 29.2 when cellulase-MCM-48 was used as a catalyst, because the effect of the enzyme was affected by the molecular structure of chitosan. When both materials were used for depolymerization, the average degree of polymerization sharply decreased to 3.8. The results show that the two degradation methods can promote each other to obtain oligosaccharides with a lower degree of polymerization. This provides a new method for the controllable degradation of chitosan and lays a good foundation for the industrial production of chitosan oligosaccharides with a low degree of polymerization.

The Pattern of Acetylation Defines the Priming Activity of Chitosan Tetramers

2019 ◽  
Author(s):  
Sven Basa ◽  
Malathi Nampally ◽  
Talita Honorato ◽  
Subha Narayan Das ◽  
Appa Rao Podile ◽  
...  
Keyword(s):  
Biological Activity ◽  
Degree Of Polymerization ◽  
Chitosan Oligosaccharides ◽  
Degree Of Acetylation ◽  
Bona Fide ◽  
First Time ◽  
Priming Activity

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of <i>β</i>-1,4-linked glucosamine (deacetylated/D) and <i>N</i>-acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially-acetylated chitosan oligosaccharides from a chitosan polymer (DA=35%, DP<sub>w</sub>=905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities. The mixtures were separated into fractions DP4–DP12, which were tested for elicitor and priming activities in rice cells. We confirmed that both activities were influenced by DP, <a>but also observed apparent DA-dependent priming activity, with the ADDD+DADD fraction proving remarkably effective</a>. We then compared all four mono-acetylated tetramers prepared using different chitin deacetylases and observed significant differences in priming activity. This demonstrates for the first time that PA influences the biological activity of chitosans, which can now be recognized as <i>bona fide</i> information-carrying molecules

The Pattern of Acetylation Defines the Priming Activity of Chitosan Tetramers

2019 ◽  
Author(s):  
Sven Basa ◽  
Malathi Nampally ◽  
Talita Honorato ◽  
Subha Narayan Das ◽  
Appa Rao Podile ◽  
...  
Keyword(s):  
Biological Activity ◽  
Degree Of Polymerization ◽  
Chitosan Oligosaccharides ◽  
Degree Of Acetylation ◽  
Bona Fide ◽  
First Time ◽  
Priming Activity

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of <i>β</i>-1,4-linked glucosamine (deacetylated/D) and <i>N</i>-acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially-acetylated chitosan oligosaccharides from a chitosan polymer (DA=35%, DP<sub>w</sub>=905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities. The mixtures were separated into fractions DP4–DP12, which were tested for elicitor and priming activities in rice cells. We confirmed that both activities were influenced by DP, <a>but also observed apparent DA-dependent priming activity, with the ADDD+DADD fraction proving remarkably effective</a>. We then compared all four mono-acetylated tetramers prepared using different chitin deacetylases and observed significant differences in priming activity. This demonstrates for the first time that PA influences the biological activity of chitosans, which can now be recognized as <i>bona fide</i> information-carrying molecules

scholarly journals Effects of Chain Length of Chitosan Oligosaccharides on Solution Properties and Complexation with siRNA

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1236 ◽  
Author(s):  
Delas ◽  
Mock-Joubert ◽  
Faivre ◽  
Hofmaier ◽  
Sandre ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Chain Length ◽  
Biological Properties ◽  
Degree Of Polymerization ◽  
Point Of View ◽  
Solution Properties ◽  
Chitosan Oligosaccharides ◽  
Colloidal Properties ◽  
Small Complex ◽  
Binding Enthalpy

In the context of gene delivery, chitosan has been widely used as a safe and effective polycation to complex DNA, RNA and more recently, siRNA. However, much less attention has been paid to chitosan oligosaccharides (COS) despite their biological properties. This study proposed to carry out a physicochemical study of COS varying in degree of polymerization (DP) from 5 to 50, both from the point of view of the solution properties and the complexing behavior with siRNA. The main parameters studied as a function of DP were the apparent pKa, the solubility versus pH, the binding affinity with siRNA and the colloidal properties of complexes. Some parameters, like the pKa or the binding enthalpy with siRNA, showed a marked transition from DP 5 to DP 13, suggesting that electrostatic properties of COS vary considerably in this range of DP. The colloidal properties of siRNA/COS complexes were affected in a different way by the COS chain length. In particular, COS of relatively high DP (≥50) were required to form small complex particles with good stability.

Clinical Evaluation of Class I Restorations Made with Composite with Low Degree of Polymerization Shrinkage

2016 ◽  
Vol 16 (9) ◽  
pp. 1-7 ◽  
Author(s):  
Carlos Gasparello ◽  
Carlos Nassar ◽  
Priscilla Busato ◽  
Márcio Mendonça ◽  
Lyvia Bertacchini ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
Degree Of Polymerization ◽  
Class I ◽  
Polymerization Shrinkage ◽  
Low Degree

scholarly journals Directed homoenzymatic fragmentation of the plant protopectin complex: Assessment criteria

2021 ◽  
pp. 254-261
Author(s):  
Vladimir Kondratenko ◽  
Tatyana Kondratenko ◽  
Andrey Petrov
Keyword(s):  
Theoretical Calculations ◽  
Functional Dependence ◽  
Degree Of Polymerization ◽  
Raw Material ◽  
Assessment Criteria ◽  
Polymerization Degree ◽  
Enzymatic Transformation ◽  
Mass Fractions ◽  
Fragmentation Potential ◽  
Enzymatic Fragmentation

Introduction. The functional basis of protopectin complex can be represented as a network of regions that consist of homogalacturonan sequences and a base of rhamnogalacturonans-I, i.e. rhamnosyl-containing branching sites. Enzymatic isolation of these regions is possible only at a certain minimal native degree of polymerization. The research objective was to develop a system of criteria for assessing the potential applicability of the enzymatic transformation of plant protopectin complex. Study objects and methods. The research featured the polymerization degree of the homogalacturonan regions of the protopectin complex and produced a system of assessment criteria for the enzymatic fragmentation potential of the protopectin complex. The theoretical calculations were based on the values of the mass fractions of rhamnosyl and galacturonide residues in plant cell walls. The result was a new polymerization degree analytical function. Results and discussion. The ratio of the mass fractions of rhamnosyl and galacturonide residues in the water-insoluble plant tissue served as a dimensionless criterion of applicability. The rational condition for the dimensionless criterion of applicability was based on the fundamental constraint for homogalacturonan regions in the protopectin complex. It was expressed by a fundamental inequation. The rational area for determining the numerical values of the applicability criterion was presented as . The functional dependence was reduced to a two-dimensional criteria space as “width of rhamnosyl branches vs. the criterion of applicability”, where each pectin-containing raw material was given a single uniquely defined position. The boundary conditions for the criteria space were determined analytically. Conclusion. The new approach offers an assessment of the enzymatic fragmentation potential of the plant protopectin complex by homoenzyme preparations. The approach is in fact the second stage of the decision tree in the science-based technology for pectin and its products.

scholarly journals Chitosan Oligosaccharides Attenuate Amyloid Formation of hIAPP and Protect Pancreatic β-Cells from Cytotoxicity

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1314 ◽  
Author(s):  
Qin-Yu Meng ◽  
Hua Wang ◽  
Zi-Bo Cui ◽  
Wen-Gong Yu ◽  
Xin-Zhi Lu
Keyword(s):  
Degree Of Polymerization ◽  
Amyloid Formation ◽  
Dependent Manner ◽  
Β Cells ◽  
Islet Amyloid ◽  
Surface Plasmon Resonance Analysis ◽  
Chitosan Oligosaccharides ◽  
Transmission Electron ◽  
Aggregation Inhibitors ◽  
Direct Binding

The deposition of aggregated human islet amyloid polypeptide (hIAPP) in the pancreas, that has been associated with β-cell dysfunction, is one of the common pathological features of patients with type 2 diabetes (T2D). Therefore, hIAPP aggregation inhibitors hold a promising therapeutic schedule for T2D. Chitosan oligosaccharides (COS) have been reported to exhibit a potential antidiabetic effect, but the function of COS on hIAPP amyloid formation remains elusive. Here, we show that COS inhibited the aggregation of hIAPP and disassembled preformed hIAPP fibrils in a dose-dependent manner by thioflavin T fluorescence assay, circular dichroism spectroscopy, and transmission electron microscope. Furthermore, COS protected mouse β-cells from cytotoxicity of amyloidogenic hIAPP, as well as apoptosis and cycle arrest. There was no direct binding of COS and hIAPP, as revealed by surface plasmon resonance analysis. In addition, both chitin-oligosaccharide and the acetylated monosaccharide of COS and glucosamine had no inhibition effect on hIAPP amyloid formation. It is presumed that, mechanistically, COS regulate hIAPP amyloid formation relating to the positive charge and degree of polymerization. These findings highlight the potential role of COS as inhibitors of hIAPP amyloid formation and provide a new insight into the mechanism of COS against diabetes.

scholarly journals Synthesis and Evaluation of a Chitosan Oligosaccharide-Streptomycin Conjugate against Pseudomonas aeruginosa Biofilms

Marine Drugs ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 43 ◽  
Author(s):  
Ruilian Li ◽  
Xianghua Yuan ◽  
Jinhua Wei ◽  
Xiafei Zhang ◽  
Gong Cheng ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Water Solubility ◽  
Efflux Pump ◽  
Degree Of Polymerization ◽  
Water Soluble ◽  
Chitosan Oligosaccharide ◽  
Gram Positive ◽  
Pump System ◽  
Gram Positive Bacteria ◽  
Chitosan Oligosaccharides

Microbial biofilms are considerably more resistant to antibiotics than planktonic cells. It has been reported that chitosan coupling with the aminoglycoside antibiotic streptomycin dramatically disrupted biofilms of several Gram-positive bacteria. This finding suggested the application of the covalent conjugate of antimicrobial natural polysaccharides and antibiotics on anti-infection therapy. However, the underlying molecular mechanism of the chitosan-streptomycin conjugate (CS-Strep) remains unclear and the poor water-solubility of the conjugate might restrict its applications for anti-infection therapy. In this study, we conjugated streptomycin with water-soluble chitosan oligosaccharides (COS). Unlike CS-Strep, the COS-streptomycin conjugate (COS-Strep) barely affected biofilms of tested Gram-positive bacteria. However, COS-Strep efficiently eradicated established biofilms of the Gram-negative pathogen Pseudomonas aeruginosa. This activity of COS-Strep was influenced by the degree of polymerization of chitosan oligosaccharide. The increased susceptibility of P. aeruginosa biofilms to antibiotics after conjugating might be related to the following: Suppression of the activation of MexX-MexY drug efflux pump system induced by streptomycin treatment; and down-regulation of the biosynthesis of biofilm exopolysaccharides. Thus, this work indicated that covalently linking antibiotics to chitosan oligosaccharides was a possible approach for the development of antimicrobial drugs against biofilm-related infections.

scholarly journals Human taste detection of glucose oligomers with low degree of polymerization

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0183008 ◽  
Author(s):  
Alexa J. Pullicin ◽  
Michael H. Penner ◽  
Juyun Lim
Keyword(s):  
Degree Of Polymerization ◽  
Low Degree ◽  
Taste Detection
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