Study of the interactions between polyphenolic compounds and chitosan (original) (raw)
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An investigation into the mode(s) of action of chitosan
A study was undertaken to understand the mechanism(s) by which chitosan exerts its antifungal effects on wood degrading fungi S. sapinea and T. harzianum. We investigated cellular responses that are known to occur in a wide range of stress situations, such as enhanced production of reactive oxygen species (ROS) and leakage of intracellular K + . An increase in the production of hydrogen peroxide and superoxide was observed especially during the initial stages of growth. Treatment with catalase caused an increase in radial growth of both fungal species, even in the presence of chitosan, suggesting that the onset of oxidative stress might be partly responsible for the observed reduction in fungal growth due to chitosan treatment. K + leakage from fungal cell increased with increasing concentrations of chitosan. Taken together these observations suggest that the plasma membrane may be the primary target of chitosan action.
Journal of Applied Polymer Science, 2002
Materials and methods Medium molecular weight chitosan [product batch #9012-76-4] with 75-85 % dcacetylated chitosan was purchased from Aldrich, Milwaukee, WI. Acetic acid [product batch #5-0994-494-138931J was purchased from s.d. fine Chemicals Ltd., Mumbai, India. The acetic acid purity, as assayed by gas chromatography, was 99.7 mol %, and its density was 1.0490 g/cnr1 at 293.15 K. Double-distilled deionized water was used throughout the research. Acetic acid-water mixtures were prepared by mass within an uncertainty of ±0.01 mg using an electronic single pan Mettler balance (A£ 240, Switzerland). Four chitosan con
Chitosan and its applications in oenology
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This paper reviews the main applications of the biopolymer chitosan, the main derivative of chitin, a material usually obtained from natural sources accessible at low cost, i.e., industrial wastes from fisheries. Due to its natural origin, which confers biodegradability and biocompatibility properties, in addition to its low toxicity, chitosan has been gaining attention in numerous sectors, such as agriculture, food, medicine, pharmaceuticals, etc., including also important oenological applications due to its potential as a green alternative to the use of sulphite. Among the many applications that can be generated from these materials in the wine-making area, their use has been reported for the clarification of must; in the preparation of films for the removal of contaminants, whether organics such as ochratoxin A or inorganics such as some metal ions and their salts; the control of turbidity caused by protein precipitation; the encapsulation of yeasts of oenological interest and en...
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This paper presents a comparative study on chitosan degradation in organic acid solutions according to their different dissociation characteristics. More precisely, the aim of the study was to determine the kinetics of the degradation process depending on the different acid dissociation constants (pKa values). The scientists involved in chitosan to date have focused mainly on acetic acid solutions. Solutions of lactic, acetic, malic, and formic acids in concentrations of 3% wt. were used in this research. The progress of degradation was determined based on the intrinsic viscosity measurement, GPC/SEC chromatographic analysis, and their correlation. Changes in the viscosity parameters were performed at a temperature of 20 °C ± 1 °C and a timeframe of up to 168 h (7 days). The chemical structure and DDA of the initial chitosan were analyzed using 1H-NMR spectroscopy analysis. The results of this study can be considered of high importance for the purpose of electrospinning, production ...
European Journal of Wood and Wood …, 2005
The uptake of chitosan based impregnation solutions were tested on Scots pine (Pinus sylvestris L), Beech (Fagus sylvatica L.), Downy birch (Betula pubescens Ehrh.) and Norway spruce (Picea abies L. Karst.) in longitudinal, radial and tangential directions separately. The four chitosans tested had a fraction of acetylated residues (F A ) of 0.198 and average molecular weights ranging from 18 to 129 kDalton. The kinetic viscosity of the 2.4% (weight/volume) solutions at pH 5.0 was in the range of 2.95 to 28.8 mm 2 s −1 . The general trend showed that there was an increase in uptake of chitosan based impregnation solutions with decreasing viscosity, and the chitosan solution with the lowest viscosity had almost comparable uptake with water for Pine and Beech in the longitudinal direction. In general, the lower the ability for uptake of impregnation solution, the more the viscosity influences the uptake.
Computational Study of Natural Phenolic Acid Solubility and Their Interactions with Chitosan
Proceedings of MOL2NET 2016, International Conference on Multidisciplinary Sciences, 2nd edition, 2017
Natural phenolic acids such as gallic, caffeic, ferulic and sinapic acids, have received great attention due to their biological activities, like antioxidant, anti-inflammatory and others. These properties put them as good candidates for the new controlled drug release systems. Among the various types of polymeric materials used in the development of controlled release systems for active drugs and films, chitosan is highlighted because it has many favorable characteristics, such as biocompatibility and biodegradability. To verify the behavior of such phenolic acids in hydrophilic biological fluids and hydrophobic biological barriers aimed at the production of new systems of modified drug release, in the present work it was conducted in silico simulation of solubility in water and in 1-octanol by molecular dynamics. The interaction of these phenolic compounds with chitosan was also investigated by molecular docking. The results showed that all investigated phenolic acids showed adequate solubility and good interaction with chitosan. The results show that the methodology applied in the present work can be well used for the development of pharmacologically active compounds and can aid the understanding of the interaction of such compounds with polymers, saving time and resources.
A comparison of the effect of chitosan at cellular level against two wood degrading fungi
An investigation was undertaken to understand the mechanism(s) by which chitosan exerts its antifungal effects against the wooddegrading fungi Sphaeropsis sapinea and Trichoderma harzianum. Exposure to increasing concentrations of chitosan caused an increase in the amount of hydrogen peroxide accumulation in cultures of S. sapinea, which was accompanied by a decrease in superoxide formation. The same effect was not observed in T. harzianum. Potassium ion leakage was an early event for both test fungi, leakage being more pronounced for S. sapinea than T. harzianum for the first 5 min, particularly at higher concentrations of chitosan treatment. Fluorescence microscopy provided evidence that the effect of chitosan on fungal hyphae was mediated through alterations in the plasma membrane properties. Chitosan also severely affected fungal morphology. Increasing concentrations of chitosan induced excessive branching, vacuolation, and a reduction in hyphal diameter. Transmission electron microscopy, which showed more severe ultrastructural changes in S. sapinea hyphae from chitosan treatment as compared to T. harzianum, provided valuable complementary information. The data suggest that the plasma membrane may be the primary target of chitosan action, and that the two fungi differ in the extent to which they are affected. r
Effectuality of chitosan biopolymer and its derivatives during antioxidant applications
International Journal of Biological Macromolecules, 2020
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Studies on the Biodegradation of Chitosan in an Aqueous Medium
Fibres & Textiles in Eastern Europe, 2003
In the previous paper [1], some results of studies on microcrystalline chitosan (MCCh) biodegradation in an aqueous medium were presented. Two forms of MCCh samples were analysed, films and lyophilizates. The dependence of biodegradation rate on the temperature ranging from 20°C to 50°C was examined. It transpired from the above studies that total degradation of MCCh (both in the form of a film and of a lyophilizate) takes Studies on the Biodegradation of Chitosan in an Aqueous Medium Maria Ratajska, Grażyna Strobin, Maria Wiśniewska-Wrona, Danuta Ciechańska, Henryk Struszczyk, Stefan Boryniec*, Dorota Biniaś*, Włodzimierz Biniaś*
International Journal of Biological Macromolecules, 1993
This paper concerns a new method of characterizing chitosans with different degrees of acetylation (DA = 2, 11.5 and 21%); it consists of steric exclusion chromatography using a multidetection instrument allowing determination of M, I-r/] and Rr for each point of the chromatograms. From these data, the Mark-Houwink parameters for intrinsic viscosity and the exponent relating R6 and M are determined. In the same way, the role of the solvent is discussed and the solvent AcOH 0.3 M/AcONa 0.2 M is proposed to reduce the presence of aggregates which perturbs static molecular weight determination by light scattering. The role of the ionic concentration and of the degree of acetylation on the stiffness of chitosan is then discussed and a theoretical treatment is proposed allowing the determination of the intrinsic persistence length (Lp = 50,4) and the prediction of the dimensions in solution (R6 and[r/I). L o is found to be independent of DA in the range tested.