Journal articles on the topic 'Chitosan'
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1
KIM, KYUNG W., R. L. THOMAS, CHAN LEE, and HYUN J. PARK. "Antimicrobial Activity of Native Chitosan, Degraded Chitosan, and O-Carboxymethylated Chitosan." Journal of Food Protection 66, no. 8 (August 1, 2003): 1495–98. http://dx.doi.org/10.4315/0362-028x-66.8.1495.
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The antimicrobial activity of native chitosan was compared to that of lipase-degradedchitosan. The effects of O-carboxymethylated (O-CM) substitution on native (molecular weight, 120; degree of deacetylation, 84.71%) and lipase-degraded chitosans were also investigated. The antimicrobial activity of native chitosan was more extensive than that of lipase-degraded chitosan; however, lipase-degraded chitosan was still highly effective and more water-soluble. O-CM chitosan derived from degraded chitosan was more effective than O-CM chitosan derived from native chitosan. O-CM substitution enhanced lipase-degraded chitosan's antimicrobial activity without reducing its solubility.
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Malm, Morgan, and Andrea M. Liceaga. "Physicochemical Properties of Chitosan from Two Commonly Reared Edible Cricket Species, and Its Application as a Hypolipidemic and Antimicrobial Agent." Polysaccharides 2, no. 2 (May 12, 2021): 339–53. http://dx.doi.org/10.3390/polysaccharides2020022.
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Insect-derived chitin and chitosan have gained interest as alternative sources to that derived from crustaceans; however, little information is available on chitin from the house cricket (Acheta domesticus) and tropical banded cricket (Gryllodes sigillatus), two cricket species commonly reared in the United States for human consumption. In this study, chitin was successfully isolated and purified from these two cricket species; using FTIR, chitins were found to be in alpha-crystalline form. Cricket chitosan was produced from both species with varying degrees of deacetylation (DDA) by varying alkaline conversion duration. G. sigillatus chitosan was larger (524 kDa) than A. domesticus chitosan (344 kDa). Both cricket chitosans showed similar (p > 0.05) lipid-binding capacity to that of shrimp chitosan. Both chitosans were as effective at inhibiting microbial growth of surrogate foodborne pathogens as the commercial shrimp chitosan. At a concentration of 0.50 mg/mL cricket chitosan, approximately 100% of Listeria innocua growth was inhibited, due to a contribution of both chitosan and the solvent-acetic acid. At the same concentration, growth of Escherichia coli was inhibited 90% by both cricket chitosan samples with ~80% DDA, where a decrease in the DDA led to decreased antimicrobial activity. However, varying the DDA had no effect on chitosan’s lipid-binding capacity. As more edible insects become a normalized protein source in our diet, the use of by-products, such as chitin and chitosan, derived from insect protein processing, show promising applications for the pharmaceutical and food industries.
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Derwich, Marcin, Lukasz Lassmann, Katarzyna Machut, Agata Zoltowska, and Elzbieta Pawlowska. "General Characteristics, Biomedical and Dental Application, and Usage of Chitosan in the Treatment of Temporomandibular Joint Disorders: A Narrative Review." Pharmaceutics 14, no. 2 (January 27, 2022): 305. http://dx.doi.org/10.3390/pharmaceutics14020305.
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The aim of this narrative review was to present research investigating chitosan, including its general characteristics, properties, and medical and dental applications, and finally to present the current state of knowledge regarding the efficacy of chitosan in the treatment of temporomandibular disorders (TMDs) based on the literature. The PICO approach was used for the literature search strategy. The PubMed database was analyzed with the following keywords: (“chitosan”[MeSH Terms] OR “chitosan”[All Fields] OR “chitosans”[All Fields] OR “chitosan s”[All Fields] OR “chitosane”[All Fields]) AND (“temporomandibular joint”[MeSH Terms] OR (“tem-poromandibular”[All Fields] AND “joint”[All Fields]) OR “temporomandibular joint”[All Fields] OR (“temporomandibular”[All Fields] AND “joints”[All Fields]) OR “temporo-mandibular joints”[All Fields]). After screening 8 results, 5 studies were included in this review. Chitosan presents many biological properties and therefore it can be widely used in several branches of medicine and dentistry. Chitosan promotes wound healing, helps to control bleeding, and is used in wound dressings, such as sutures and artificial skin. Apart from its antibacterial property, chitosan has many other properties, such as antifungal, mucoadhesive, anti-inflammatory, analgesic, antioxidant, antihyperglycemic, and antitumoral properties. Further clinical studies assessing the efficacy of chitosan in the treatment of TMD are required. According to only one clinical study, chitosan was effective in the treatment of TMD; however, better clinical results were obtained with platelet-rich plasma.
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Cahyono, Eko, Stevy Imelda Murniati Wodi, and Jumardi Tondais. "KARAKTERISASI CHITOSAN DAN CHITOSAN POLYMER MEDIUM DARI CANGKANG KEPITING BATU." Jurnal Ilmiah Tindalung 6, no. 1 (March 3, 2020): 14–20. http://dx.doi.org/10.54484/jit.v6i1.343.
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Kepiting batu (Grapsus albolineatus) merupakan spesies yang banyak ditemukan di pantai berbatu dan eksoskeletonnya adalah salah sumber potensial chitin-chitosan. Chitosan adalah polimer bersifat polikationik dengan chitosan polymer medium (CPM) yang memiliki molekul lebih sederhana sebagai salah satu turunannya. Tujuan penelitian ini adalah untuk menentukan mutu chitosan dan chitosan polymer medium dari cangkang kepiting batu. Metode yang digunakan pada penelitian ini adalah metode eksperimental. Hasil analisis membuktikan bahwa cangkang kepiting memiliki komposisi 4.17±0.08 air, 54.4±2.78 abu, 6.28±0.05 lemak, 23.48±0.01 protein, 11.70±2.93 kaborhidrat. Karakterisasi chitosan memperlihatkan rendemen sebesar 10±0.70%, kadar air 8.10±0.14%, abu 19.39±0.55%, lemak 6.26±0.37%, protein 8.24±0.34%, karbodidrat 50.03±0.04%, derajat putih 60.61±0.86% , viscositas 7.30±0.42 cps dan derajat deasetilasi 55.92±1.30%. Untuk chitosan polymer medium, rendemennya mencapai 98.33±0.40% dan derajat deasetilasinya sebesar 60.22±0.24%. Chitosan dan chitosan polymer medium dari cangkang kepiting batu (Grapsus albolineatus) masih memenuhi standar yang ditetapkan SNI.
Stone crab (Grapsus albolineatus) is a species commonly found in rocky beaches. Its exoskeleton is a good source of chitin and/or chitosan. Chitosan represents a polycationic polymer with chitosan polymer medium (CPM) having simpler molecular formula than chitosan as chitosan’s derivative. The objective of this research was to determine the quality of chitosan and chitosan polymer medium from rock crab’s shells. Experimental method was used in this study with characterization of the crab’s shells showing a composition of 4.17±0.08%, water, 54.4±2.78% ash, 6.28±0.05% fat, 23.48±0.01% protein and 11.70±2.93% carbohydrate. Similar characterization on chitosan revealed a composition of 10±0.70% rendemen, 8.10±0.14% water, 19.39±0.55% ash, 6.26±0.37% fat, 8.24±0.34% protein, 50.03±0.04% charabohydrate, 60.61±0.86% white degree, 7.30±0.42 cps viscosity and 55.92±1.30% degrees of deacetylation. Although chitosan contained similar composition of white degree (60%) and deactylation (60%0 to chitoxan polymer medium, CPM had higher composition of rendemen (98.33±0.40%) than chitosan (10±0.70%). In conclusion, this study shows that chitosan and chitosan polymer medium of G. albolineatus met our national standard (SNI).
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Khayrova, Adelya, Sergey Lopatin, Balzhima Shagdarova, Olga Sinitsyna, Arkady Sinitsyn, and Valery Varlamov. "Evaluation of Antibacterial and Antifungal Properties of Low Molecular Weight Chitosan Extracted from Hermetia illucens Relative to Crab Chitosan." Molecules 27, no. 2 (January 17, 2022): 577. http://dx.doi.org/10.3390/molecules27020577.
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This study shows the research on the depolymerisation of insect and crab chitosans using novel enzymes. Enzyme preparations containing recombinant chitinase Chi 418 from Trichoderma harzianum, chitinase Chi 403, and chitosanase Chi 402 from Myceliophthora thermophila, all belonging to the family GH18 of glycosyl hydrolases, were used to depolymerise a biopolymer, resulting in a range of chitosans with average molecular weights (Mw) of 6–21 kDa. The depolymerised chitosans obtained from crustaceans and insects were studied, and their antibacterial and antifungal properties were evaluated. The results proved the significance of the chitosan’s origin, showing the potential of Hermetia illucens as a new source of low molecular weight chitosan with an improved biological activity.
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Coquery, Clément, Claire Negrell, Nicolas Caussé, Nadine Pébère, and Ghislain David. "Synthesis of new high molecular weight phosphorylated chitosans for improving corrosion protection." Pure and Applied Chemistry 91, no. 3 (March 26, 2019): 509–21. http://dx.doi.org/10.1515/pac-2018-0509.
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Abstract Two grades of chitosan [chitosan 30000 g mol−1 (N-chitosan 30) and 250000 g mol−1 (N-chitosan 250)] were functionalized by the Kabachnik–Fields reaction. To obtain the highest phosphonic ester grafting rate (55% and 40% for the N-chitosan 30 and N-chitosan 250, respectively), the pH must be kept constant during the reaction (pH=5). Then, a partial hydrolysis of the ester functions was carried out in HCl medium to generate phosphonic acid functions up to 25% and 20% for the N-chitosan 30 and N-chitosan 250, respectively. It was shown that the grafting of phosphonic acids on chitosan significantly reduced the dynamic viscosity. Afterwards, electrochemical impedance measurements were performed in an aqueous solution (pH=5) in the presence of either N-chitosans or P-chitosans (3 wt.%). The two native N-chitosans were little adsorbed onto the carbon steel surface and the corrosion protection was low. In contrast, the impedance results in the presence of the 30000 g mol−1 phosphorylated chitosan (P-chitosan 30) evidenced the beneficial effect of grafted phosphonic acid on its adsorption on the steel surface. The lower efficiency of the 250000 g mol−1 (P-chitosan 250) was attributed to its high molecular weight which made difficult the interactions between the phosphonic groups and the metallic surface.
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Wang, Hezhong, and Maren Roman. "Effects of Chitosan Molecular Weight and Degree of Deacetylation on Chitosan−Cellulose Nanocrystal Complexes and Their Formation." Molecules 28, no. 3 (January 31, 2023): 1361. http://dx.doi.org/10.3390/molecules28031361.
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This study was conducted to determine the effects of chitosan molecular weight and degree of deacetylation (DD) on chitosan–cellulose nanocrystal (CNC) polyelectrolyte–macroion complexes (PMCs) and their formation. Chitosan samples with three different molecular weights (81, 3 · 103, 6 · 103 kDa) and four different DDs (77, 80, 85, 89%) were used. The effects on PMC formation were determined by turbidimetric titration. An effect of the molecular weight of chitosan was not observed in turbidimetric titrations. Turbidity levels were higher for CNCs with lower sulfate group density and larger hydrodynamic diameter than for CNCs with higher sulfate group density and smaller hydrodynamic diameter. Conversely, turbidity levels were higher for chitosans with higher DD (higher charge density) than for chitosans with lower DD (lower charge density). PMC particles from chitosans with different molecular weights were characterized by scanning electron microscopy, laser Doppler electrophoresis, and dynamic light scattering. PMCs from high-molecular-weight chitosan were more spherical and those from medium-molecular-weight chitosan had a slightly larger hydrodynamic diameter than PMCs from the respective other two chitosans. The molecular weight of the chitosan was concluded to have no effect on the formation of chitosan–CNC PMC particles and only a minor effect on the shape and size of the particles. The higher turbidity levels for CNCs with lower sulfate group density and larger hydrodynamic diameter and for chitosans with higher DD were attributed to a larger number of CNCs being required for charge compensation.
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Ortega-Ortiz, Hortensia, Baltazar Gutiérrez-Rodríguez, Gregorio Cadenas-Pliego, and Luis Ibarra Jimenez. "Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan." Brazilian Archives of Biology and Technology 53, no. 3 (June 2010): 623–28. http://dx.doi.org/10.1590/s1516-89132010000300016.
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The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid).
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Jaidee, A., Pornchai Rachtanapun, and S. Luangkamin. "1H-NMR Analysis of Degree of Substitution in N,O-Carboxymethyl Chitosans from Various Chitosan Sources and Types." Advanced Materials Research 506 (April 2012): 158–61. http://dx.doi.org/10.4028/www.scientific.net/amr.506.158.
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N,O-Carboxymethyl chitosans were synthesized by the reaction between shrimp, crab and squid chitosans with monochloroacetic acid under basic conditions at 50°C. The mole ratio of reactants was obtained from various reaction conditions of shrimp chitosan polymer and oligomer types. The mole ratio 1:12:6 of chitosan:sodium hydroxide:monochloroacetic acid was used for preparing carboxymethyl of chitosan polymer types while carboxymethyl of chitosan oligomer types were used the mole ratio 1:6:3 of chitosan:sodium hydroxide:monochloroacetic acid. The chemical structure was analyzed by fourier transformed infrared spectroscopy (FT-IR) and proton nuclear magnatic resonance spectroscopy (1H-NMR). The FT-IR was used for confirm the insertion of carboxymethyl group on chitosan molecules. The 1H-NMR was used for determining the degree of substitution (DS) of carboxymethylation at hydroxyl and amino sites of chitosans. Carboxymethyl chitosan samples had the total DS of carboxymethylation ranging from 1.0-2.2. The highest of DS of carboxymethylation was from shrimp chitosan oligomer type.
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Lončarević, Andrea, Karla Ostojić, Inga Urlić, and Anamarija Rogina. "Preparation and Properties of Bimetallic Chitosan Spherical Microgels." Polymers 15, no. 6 (March 16, 2023): 1480. http://dx.doi.org/10.3390/polym15061480.
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The aim of this work was to prepare bimetallic chitosan microgels with high sphericity and investigate the influences of metal-ion type and content on the size, morphology, swelling, degradation and biological properties of microgels. Amino and hydroxyl groups of chitosan (deacetylation degree, DD, of 83.2% and 96.9%) served as ligands in the Cu2+–Zn2+/chitosan complexes with various contents of cupric and zinc ions. The electrohydrodynamic atomization process was used to produce highly spherical microgels with a narrow size distribution and with surface morphology changing from wrinkled to smooth by increasing Cu2+ ions’ quantity in bimetallic systems for both used chitosans. The size of the bimetallic chitosan particles was estimated to be between 60 and 110 µm for both used chitosans, and FTIR spectroscopy indicated the formation of complexes through physical interactions between the chitosans’ functional groups and metal ions. The swelling capacity of bimetallic chitosan particles decreases as the DD and copper (II) ion content increase as a result of stronger complexation with respect to zinc (II) ions. Bimetallic chitosan microgels showed good stability during four weeks of enzymatic degradation, and bimetallic systems with smaller amounts of Cu2+ ions showed good cytocompatibility for both used chitosans.
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Abenaim, Linda, and Barbara Conti. "Chitosan as a Control Tool for Insect Pest Management: A Review." Insects 14, no. 12 (December 15, 2023): 949. http://dx.doi.org/10.3390/insects14120949.
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Chitosan, a polysaccharide derived from the deacetylation of chitin, is a versatile and eco-friendly biopolymer with several applications. Chitosan is recognized for its biodegradability, biocompatibility, and non-toxicity, beyond its antimicrobial, antioxidant, and antitumoral activities. Thanks to its properties, chitosan is used in many fields including medicine, pharmacy, cosmetics, textile, nutrition, and agriculture. This review focuses on chitosan’s role as a tool in insect pest control, particularly for agriculture, foodstuff, and public health pests. Different formulations, including plain chitosan, chitosan coating, chitosan with nematodes, chitosan’s modifications, and chitosan nanoparticles, are explored. Biological assays using these formulations highlighted the use of chitosan–essential oil nanoparticles as an effective tool for pest control, due to their enhanced mobility and essential oils’ prolonged release over time. Chitosan’s derivatives with alkyl, benzyl, and acyl groups showed good activity against insect pests due to improved solubility and enhanced activity compared to plain chitosan. Thus, the purpose of this review is to provide the reader with updated information concerning the use and potential applications of chitosan formulations as pest control tools.
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Gomes, Laidson, Hiléia Souza, José Campiña, Cristina Andrade, António Silva, Maria Gonçalves, and Vania Paschoalin. "Edible Chitosan Films and Their Nanosized Counterparts Exhibit Antimicrobial Activity and Enhanced Mechanical and Barrier Properties." Molecules 24, no. 1 (December 31, 2018): 127. http://dx.doi.org/10.3390/molecules24010127.
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Chitosan and chitosan-nanoparticles were combined to prepare biobased and unplasticized film blends displaying antimicrobial activity. Nanosized chitosans obtained by sonication for 5, 15, or 30 min were combined with chitosan at 3:7, 1:1, and 7:3 ratios, in order to adjust blend film mechanical properties and permeability. The incorporation of nanosized chitosans led to improvements in the interfacial interaction with chitosan microfibers, positively affecting film mechanical strength and stiffness, evidenced by scanning electron microscopy. Nanosized or blend chitosan film sensitivity to moisture was significantly decreased with the drop in biocomposite molecular masses, evidenced by increased water solubility and decreased water vapor permeability. Nanosized and chitosan interactions gave rise to light biobased films presenting discrete opacity and color changes, since red-green and yellow-blue colorations were affected. All chitosan blend films exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. The performance of green unplasticized chitosan blend films displaying diverse morphologies has, thus, been proven as a potential step towards the design of nontoxic food packaging biobased films, protecting against spoilage microorganisms, while also minimizing environmental impacts.
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Xu, Qing, Tian Zhong, and Hui Li Li. "Antioxidant and Free Radical Scavenging Activities of N-Modified Chitosans." Advanced Materials Research 1002 (August 2014): 91–98. http://dx.doi.org/10.4028/www.scientific.net/amr.1002.91.
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Recently, the search for effective natural antioxidants use in food and medicinal fields to replace synthetic ones has attracted the most attention. Chitosan, a natural nontoxic biopolymer, is known to possess antioxidant property, which is attributed that NH2 and OH attached in the pyranose ring react with unstable free radicals to form stable macromolecule radicals. It has been observed that the antioxidant activity of chitosan is closely related to the form of nitrogen atom in the molecules. This review focuses on the antioxidant and free radical scavenging activities of various nitrogen atom of chitosan, including N-acylated chitosans, Schiff bases of chitosan, N-alkyl chitosan, and N-quaternized chitosan. The free radical scavenging mechanisms are summarized and the effects on free radical scavenging activity of N-modified chitosan are discussed. This work may provide more insights into the antioxidant ability of N-modified chitosans and potentially enable them to be used as natural antioxidants for application in food, agriculture, cosmetic and biomedical science. Keywords: N-modified chitosan, Sythesis, Antioxidant, Free radical scavenging
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Pokhrel, Shanta, Ralf Lach, Wolfgang Grellmann, Andre Wutzler, Werner Lebek, Reinhold Godehardt, Paras Nath Yadav, and Rameshwar Adhikari. "Synthesis of Chitosan from Prawn Shells and Characterization of its Structural and Antimicrobial Properties." Nepal Journal of Science and Technology 17, no. 1 (July 31, 2016): 5–9. http://dx.doi.org/10.3126/njst.v17i1.25056.
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Chitin was prepared from prawn shells waste by chemical treatments viz. demineralization, deproteinization and decolorization. Chitosan was prepared by deacetylation of chitin with 50% NaOH at 100 °C in the presence of nitrogen. Deacetylation was performed at different intervals of time to get a series of chitosans having different degrees of deacetylation. Prepared chitosans were characterized by molecular weight determination, degree of deacetylation, Fourier transform infrared (FTIR) spectroscopy and Scanning electron micrography (SEM). The degree of deacetylation of chitosans was calculated by acid base titration and potentiometric titration. The molecular weights of commercial and prepared chitosan (CS-4.0) samples were determined using the Mark- Houwink equation and were found to be 3.5 × 105 (g/mole) and 3.3 × 104 (g/mole), respectively. The degree of deacetylation was found to linearly increase with the increase of reaction time. FTIR spectra showed the characteristic peaks of chitin and chitosan. Antimicrobial screening results revealed that the prepared chitosan (CS-4.0) was equally or more biologically active than the commercial chitosan.
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GANAN, M., A. V. CARRASCOSA, and A. J. MARTÍNEZ-RODRÍGUEZ. "Antimicrobial Activity of Chitosan against Campylobacter spp. and Other Microorganisms and Its Mechanism of Action." Journal of Food Protection 72, no. 8 (August 1, 2009): 1735–38. http://dx.doi.org/10.4315/0362-028x-72.8.1735.
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The antimicrobial activities of three chitosans with different molecular masses against six gram-negative and three gram-positive bacteria were examined. Campylobacter spp. were the microorganisms most sensitive to chitosan, regardless of their molecular mass. The MIC of chitosan for Campylobacter ranged from 0.005 to 0.05%, demonstrating the global sensitivity of campylobacters to chitosan. Chitosan caused a loss in the membrane integrity of Campylobacter, measured as an increase in cell fluorescence due to the uptake of propidium iodide, a dye that is normally excluded from cells with intact membranes. As cells entered the stationary phase, there was a change in cell membrane resistance toward a loss of integrity caused by chitosan. This study demonstrates that chitosans could be a promising antimicrobial to control Campylobacter.
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Mati-Baouche, Narimane, Cédric Delattre, Hélène de Baynast, Michel Grédiac, Jean-Denis Mathias, Alina Violeta Ursu, Jacques Desbrières, and Philippe Michaud. "Alkyl-Chitosan-Based Adhesive: Water Resistance Improvement." Molecules 24, no. 10 (May 23, 2019): 1987. http://dx.doi.org/10.3390/molecules24101987.
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A chemical modification by grafting alkyl chains using an octanal (C8) on chitosan was conducted with the aim to improve its water resistance for bonding applications. The chemical structure of the modified polymers was determined by NMR analyses revealing two alkylation degrees (10 and 15%). In this study, the flow properties of alkyl-chitosans were also evaluated. An increase in the viscosity was observed in alkyl-chitosan solutions compared with solutions of the same concentration based on native chitosan. Moreover, the evaluation of the adhesive strength (bond strength and shear stress) of both native and alkyl-chitosans was performed on two different double-lap adherends (aluminum and wood). Alkyl-chitosans (10 and 15%) maintain sufficient adhesive properties on wood and exhibit better water resistance compared to native chitosan.
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Fu, Ran Ran, Xiu Jie Ji, Yan Fei Ren, Gang Wang, and Bo Wen Cheng. "Different Molecular Weight Chitosans Prepared via the Ionic Liquid Hydrolysis and their Antibacterial Activity." Key Engineering Materials 730 (February 2017): 127–34. http://dx.doi.org/10.4028/www.scientific.net/kem.730.127.
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The hydrolysis effect of ionic liquid glycine chloride [Gly]Cl aqueous system without any catalyst on the degradation for chitosan were studied. The molecular weight (Mw) and degree of deacetylation (DD) of degraded products were tested via the viscometric method and the titration method, respectively. The structure of the raw and degraded chitosans were assessed through Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). Besides, the antibacterial effects of different Mw chitosans to Escherichia coli and Staphylococcus aureus were evaluated. The results showed that [Gly]Cl aqueous solution was of good assistant degradation effect for chitosan and different molecular weight (300-800 kDa) chitosans were obtained with different processing time via the ionic liquid hydrolysis method. The DD of degraded chitosans tested from titration method was almost unchanged by the treatment. The FTIR and XRD results showed that the ionic liquid degradation had no obvious effect on the molecular structure of chitosan. Besides, the antibacterial activity was closely relevant to the chitosan concentration and Mw. When the concentration was greater than 0.005% (w/v), chitosan began to show strong antibacterial activity. Molecular weight of 636 kDa exhibited commendable antimicrobial properties to E. coli and S. aureus simultaneously.
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Basseri, Hamidreza, Ronak Bakhtiyari, Sayed Jamal Hashemi, Mojgan Baniardelani, Hadi Shahraki, and Laila Hosainpour. "Antibacterial/Antifungal Activity of Extracted Chitosan From American Cockroach (Dictyoptera: Blattidae) and German Cockroach (Blattodea: Blattellidae)." Journal of Medical Entomology 56, no. 5 (May 29, 2019): 1208–14. http://dx.doi.org/10.1093/jme/tjz082.
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Abstract We investigated bactericidal and fungicidal properties of chitosan extracted from adults and nymphs from both German cockroach, Blattella germanica (Blattodea: Blattellidae) and American cockroach, Periplaneta americana (Dictyoptera: Blattidae). The cuticle of adults and nymphs extracted from both cockroaches were dried and ground. The powders were demineralized and deproteinized followed by deacetylation using NaOH. Finally, the chitosan yields were examined for antibacterial and antifungal activities. The degree of deacetylation (DD) was different between adults and nymph stages. The antimicrobial effect of American cockroach chitosan (ACC) and German cockroach chitosan (GCC) was tested against four bacteria and four fungi. The extracted chitosans from American cockroach, Periplaneta americana and German Cockroach, Blattella germanica suppressed the growth of Gram-negative/positive bacteria except Micrococcus luteus. The growth of Aspergillus flavus and Aspergillus niger were notability inhibited by the extracted chitosans. The antimicrobial effect of the chitosan depended on the cockroach species, with chitosan of the American cockroach showing more inhibitory effect. This difference may be due to differences in the structure of chitin between the two cockroach species.
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Vendramin, Veronica, Gaia Spinato, and Simone Vincenzi. "Shellfish Chitosan Potential in Wine Clarification." Applied Sciences 11, no. 10 (May 13, 2021): 4417. http://dx.doi.org/10.3390/app11104417.
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Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.
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Rabea, E. I., and W. Steurbaut. "Chemically modified chitosans as antimicrobial agents against some plant pathogenic bacteria and fungi." Plant Protection Science 46, No. 4 (December 14, 2010): 149–58. http://dx.doi.org/10.17221/9/2009-pps.
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The antimicrobial activity of eight chemically modified chitosans against plant pathogenic bacteria of crown gall disease Agrobacterium tumefaciens and soft mould disease Erwinia carotovora and fungi of early blight disease Alternaria alternata, root rot disease Fusarium oxysporum, and damping off disease Pythium debaryanum was investigated. The minimum inhibitory concentration (MIC) of these compounds against the tested bacteria showed that N-(o,o-dichlorobenzyl)chitosan exhibited a high activity against A. tumefaciens and E. carotovora (MIC = 500 and 480 mg/l, respectively). In addition, the antifungal behaviour was investigated in vitro on mycelial growth and spore germination. N-(p-fluorobenzyl)chitosan was the most active against the mycelial growth of A. alternata with an EC<sub>50</sub> of 703.4 mg/l, while the N-(o-chloro,o-fluorobenzyl)chitosan exhibited a high activity against F. oxysporum and P. debaryanum (EC<sub>50</sub> = 641.2 and 155.7 mg/l, respectively). Against the fungal spore germination, all modified chitosans showed a higher inhibition of spore germination than unmodified chitosan. The compound of N-(o,o-di fluorobenzyl)chitosan exhibited a high inhibition percentage against A. alternata. However, N-(o-chlorobenzyl)chitosan and N-(p-chlorobenzyl)chitosan were significantly highly active against the spore germination of F. oxysporum.
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Chen, Zhi Qing, Quan Li Li, Quan Zen, Gang Li, Hao Bin Jiang, Laikui Liu, and Brian W. Darvell. "Biomimetic Mineralization and Bioactivity of Phosphorylated Chitosan." Key Engineering Materials 288-289 (June 2005): 429–32. http://dx.doi.org/10.4028/www.scientific.net/kem.288-289.429.
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Phosphorylated chitosans were synthesized as templates to manipulate hydroxyapatite (HA) crystal nucleation, growth and microstructure. Two kinds of insoluble phosphorylated chitosan were soaked in saturated Ca(OH)2 solution for 4 d and in 1.5× SBF (simulated body fluid) solutions for 14 d at 37 °C for biomimetic mineralization. A lower [P]-content of phosphorylated chitosan promoted greater mineralization than higher [P]-content. Phosphorylated chitosan inhibited osteoblast proliferation and differentiation in vitro, while calcium phosphate phosphorylated chitosan composites did not.
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Qin, Xiaofei, Jana Emich, and Francisco Goycoolea. "Assessment of the Quorum Sensing Inhibition Activity of a Non-Toxic Chitosan in an N-Acyl Homoserine Lactone (AHL)-Based Escherichia coli Biosensor." Biomolecules 8, no. 3 (September 4, 2018): 87. http://dx.doi.org/10.3390/biom8030087.
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New approaches to deal with drug-resistant pathogenic bacteria are urgent. We studied the antibacterial effect of chitosans against an Escherichia coli quorum sensing biosensor reporter strain and selected a non-toxic chitosan to evaluate its quorum sensing (QS) inhibition activity and its effect on bacterial aggregation. To this end, chitosans of varying degree of acetylation (DA) (12 to 69%) and molecular weight (Mw) (29 to 288 kDa) were studied. Only chitosans of low DA (~12%) inhibited bacterial growth, regardless of their Mw. A chitosan with medium degree of polymerization (named MDP) DA30, with experimental DA 42% and Mw 115 kDa was selected for further QS inhibition and scanning electron microscopy (SEM) imaging studies. MDP DA30 chitosan exhibited QS inhibition activity in an inverse dose-dependent manner (≤12.5 µg/mL). SEM images revealed that this chitosan, when added at low concentration (≤30.6 µg/mL), induced substantial bacterial aggregation, whereas at high concentration (234.3 µg/mL), it did not. Aggregation explains the QS inhibition activity as the consequence of retardation of the diffusion of N-acylated homoserine lactones (AHLs).
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CHEN, CHEE-SHAN, WAN-YU LIAU, and GUO-JANE TSAI. "Antibacterial Effects of N-Sulfonated and N-Sulfobenzoyl Chitosan and Application to Oyster Preservation." Journal of Food Protection 61, no. 9 (September 1, 1998): 1124–28. http://dx.doi.org/10.4315/0362-028x-61.9.1124.
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The antibacterial effects of sulfonated and sulfobenzoyl chitosans were evaluated and compared with that of 69% deacetylated chitosan (DD69 chitosan). Minimal inhibitory concentrations of sulfonated chitosan (SC1, 0.63% sulfur content) against Shigella dysenteriae, Aeromonas hydrophila, Salmonella typhimurium, and Bacillus cereus were found to be lower than those of DD69 chitosan. A high sulfur content in sulfonated chitosan adversely influenced its antibacterial effect. Sulfobenzoyl chitosan (SBC) has excellent water solubility and an antibacterial effect comparable to that of SC1. SBC at 1,000 and 2,000 ppm extended the shelf life of oysters at 5°C by 4 days at the former or by 7 days at least at the latter concentration. The growth of coliforms and Pseudomonas, Aeromonas, and Vibrio species on oysters was retarded by the addition of DD69 chitosan or SBC.
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Strzałka, Anna, Renata Lubczak, and Jacek Lubczak. "Chitosan Oligomer as a Raw Material for Obtaining Polyurethane Foams." Polymers 15, no. 14 (July 18, 2023): 3084. http://dx.doi.org/10.3390/polym15143084.
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Decreasing oil extraction stimulates attempts to use biologically available sources to produce polyols, which are the basic components for obtaining polyurethane foams. Plants are inexhaustible source of oils, sugars, starches, and cellulose. Similar substrates to obtain polyols are chitosans. Commercially available modified chitosans are soluble in water, which gives them the possibility to react with hydroxyalkylating agents. We used a water-soluble chitosan previously to obtain polyols suitable for producing rigid polyurethane foams. Here, we described hydroxyalkylation of a low-molecular-weight chitosan (oligomeric chitosan) with glycidol and ethylene carbonate to obtain polyols. The polyols were isolated and studied in detail by IR, 1H-NMR, and MALDI–ToF methods. Their properties, such as density, viscosity, surface tension, and hydroxyl numbers, were determined. The progress of the hydroxyalkylation reaction of water-soluble chitosan and chitosan oligomer with glycidol was compared in order to characterize the reactivity and mechanism of the process. We found that the hydroxyalkylation of chitosan with glycidol in glycerol resulted in the formation of a multifunctional product suitable for further conversion to polyurethane foams with favorable properties. The straightforward hydroxyalkylation of chitosan with glycidol was accompanied by the oligomerization of glycidol. The hydroxyalkylation of chitosan with glycidol in the presence of ethylene carbonate was accompanied by minor hydroxyalkylation of chitosan with ethylene carbonate. The chosen polyols were used to obtain rigid polyurethane foams which were characterized by physical parameters such as apparent density, water uptake, dimension stability, heat conductance, compressive strength, and heat resistance at 150 and 175 °C. The properties of polyurethane foams obtained from chitosan-oligomer and water-soluble-chitosan sources were compared. Polyurethane foams obtained from polyols synthesized in the presence of glycerol had advantageous properties such as low thermal conductivity, enhanced thermal resistance, dimensional stability, low water uptake, and high compressive strength, growing remarkably upon thermal exposure.
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Jin, Zheng, Kai Zhao, Gang Chen, and Xu Zhang. "Preparation and Characterization of 2-Hydroxypropyltrimcthyl Ammonium Chloride Chitosan." Advanced Materials Research 183-185 (January 2011): 2216–20. http://dx.doi.org/10.4028/www.scientific.net/amr.183-185.2216.
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Chitosan has the potential to act as mediators of DNA transfection targeted to phagocytic cells such as macrophages, and to protect against biological degradation by nucleases as well as enhance gene expression. However, the poor solubility of Chitosan is the major limiting factor in its utilization. 2-hydroxypropyltrimcthyl ammonium chloride Chitosan has be prepared successfully through covalent binding of 2,3-Epoxypropyltrimethylammonium chloride ligands to the polymer’s primary amino groups and the polymer’s structure was verified with FT-IR spectra and NMR spectra. The new polymers were obtained with degree of quaternization (DQ) values around 34%, except in the case of the Phe-derived polymer, and thus possess reduced net positive charge as compared to the parent Chitosan. This study provided the new peptide-Chitosans with full water-solubility over practically the entire physiological pH range and led to more disordered. Globally, the new peptide Chitosans and especially the Asp-derived polymer, possess physico-chemical properties that turn them into promising candidates as novel Chitosan-based vaccine delivery systems.
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MOOLPHUERK, Namphueng, and Wattana PATTANAGUL. "Pretreatment with different molecular weight chitosans encourages drought tolerance in rice (Oryza sativa L.) seedling." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 48, no. 4 (December 22, 2020): 2072–84. http://dx.doi.org/10.15835/nbha48412018.
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Drought is a critical environmental constraint limiting plant growth and productivity. Chitosan has been utilized as a potential biostimulant and proven to be effective against drought stress in many plant species. The objective of this study was to determine the effects of pretreatment with different molecular weight (MW) chitosans on some physiological characteristics of rice seedlings under drought stress. Rice seedlings were treated with low (50-190 kDa), medium (190-310 kDa) and high (310-375 kDa) MW chitosans by seed priming and foliar spray. The seedlings were subjected to drought by withholding water for four days. The relative water content (RWC) was reduced from 93% in the control plants to 74% in the droughted plants. The results revealed that treating with chitosan, especially with low MW chitosan, promoted root growth under drought stress. All chitosan treatments led to higher relative water content and photosynthetic pigment under drought condition. Pretreatment with chitosan also induced sugar accumulation, and treating with low MW chitosan significantly increased starch accumulation under drought stress. In addition, chitosan treatments alleviated the effects caused by drought stress as represented by the decreases in electrolyte leakage, malondialdehyde (MDA) as well as hydrogen peroxide (H2O2), corresponding with the increases in activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (GPX) activity.
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Mello, Karine Gargioni Pereira Correa de, Leandra de Cássia Bernusso, Ronaldo Nogueira de Moraes Pitombo, and Bronislaw Polakiewicz. "Synthesis and physicochemical characterization of chemically modified chitosan by succinic anhydride." Brazilian Archives of Biology and Technology 49, no. 4 (July 2006): 665–68. http://dx.doi.org/10.1590/s1516-89132006000500017.
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The N-succinil-chitosan is a chemically modified derivative of the biopolymer chitosan. The succinic anhydride attached to the free amino groups presented along the chitosan's polymer chain imparts to the molecule different physicochemical properties not exhibited before the modification. These chemical modifications enhance chitosan's solubility in slightly acid, neutral and alkaline media. These properties are related to the long alkyl chains attached to hydrophilic parts. In this case the hydrophilic part of D-glucosamine promotes stronger interactions with the water molecules, and consequently, enhances the solubility of the chitosan polymer. Non-modified free chitosan is soluble only in acidic medium (pH < 5.5). These modifications made possible new applications of chitosan in biotechnological area since the solubility in neutral or slightly alkaline solutions is very important in a biological field.
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Wang, An Na, Li Gen Wu, Lin Lu Jia, Yu Dan Sun, Xiu Ling Li, Xiang Ying Xu, Jie Wang, Chao Wang, Yuan Yuan Zhang, and Qin Qin Fu. "Encapsulation of Glycoprotein Extracted from Kiwifruit in Chitosan-Based Microspheres." Advanced Materials Research 197-198 (February 2011): 225–28. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.225.
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Encapsulation glycoprotein extracted from kiwifruit in chitosan-alginate microspheres was prepared by ionic gelation method for controlling release by using various combinations of chitosn and Ca2+as cation and alginate as anion. The concentration of chitosan, sodium alginate and calcium chloride could affect glycoprotein loading efficiency and the total release capacity of glycoprotein from chitosan-alginate microspheres. The maxmum amount of glycoprotein loaded and the minimum total release capacity were attained when 2% alginate, 0.7% chitosan, and 0.2M Ca2+were crosslinked at pH 5.5, 37°C.
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Benabbou, R., A. Zihler, M. Desbiens, E. Kheadr, M. Subirade, and I. Fliss. "Inhibition ofListeria monocytogenesby a combination of chitosan and divergicin M35." Canadian Journal of Microbiology 55, no. 4 (April 2009): 347–55. http://dx.doi.org/10.1139/w08-154.
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The antimicrobial activities of the class IIa bacteriocin divergicin M35 and several types of chitosan against Listeria monocytogenes were quantified by agar diffusion, critical micro-dilution, and viable count and observed by electron microscopy. Antimicrobial activity of chitosan depended on its molecular mass (MM) and the pH. Three chitosans with MM values of 2, 20, and 100 kDa and 87.4% degree of deacetylation (DDA) were chosen for further study, based on high anti-listerial activity at pH 4.5. Electron microscopy suggested that the mechanism of anti-listerial activity also varied with the MM. Low-MM chitosan appeared to inhibit L. monocytogenes by affecting cell permeability and growth, whereas medium- and high-MM chitosan may form a barrier on the cell surface that prevents entry of nutrients. The minimum inhibitory concentrations (MICs) of 2, 20, and 100 kDa chitosan and divergicin M35 against a divergicin-resistant strain of L. monocytogenes (LSD 535) were 2.5, 2.5, 0.625, and 0.25 mg/mL, respectively. The combination of any of these 3 chitosans and divergicin M35 appeared to have an additive effect against L. monocytogenes, as determined by fractional inhibitory concentration (FIC) index. This study provides useful data for the development of chitosan films incorporating divergicin M35 for inhibiting L. monocytogenes in foods.
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Gubaeva, Ekaterina, Airat Gubaev, Rebecca L. J. Melcher, Stefan Cord-Landwehr, Ratna Singh, Nour Eddine El Gueddari, and Bruno M. Moerschbacher. "‘Slipped Sandwich’ Model for Chitin and Chitosan Perception in Arabidopsis." Molecular Plant-Microbe Interactions® 31, no. 11 (November 2018): 1145–53. http://dx.doi.org/10.1094/mpmi-04-18-0098-r.
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Chitin, a linear polymer of N-acetyl-d-glucosamine, and chitosans, fully or partially deacetylated derivatives of chitin, are known to elicit defense reactions in higher plants. We compared the ability of chitin and chitosan oligomers and polymers (chitin oligomers with degree of polymerization [DP] 3 to 8; chitosan oligomers with degree of acetylation [DA] 0 to 35% and DP 3 to 15; chitosan polymers with DA 1 to 60% and DP approximately 1,300) to elicit an oxidative burst indicative of induced defense reactions in Arabidopsis thaliana seedlings. Fully deacetylated chitosans were not able to trigger a response; elicitor activity increased with increasing DA of chitosan polymers. Partially acetylated chitosan oligomers required a minimum DP of 6 and at least four N-acetyl groups to trigger a response. Invariably, elicitation of an oxidative burst required the presence of the chitin receptor AtCERK1. Our results as well as previously published studies on chitin and chitosan perception in plants are best explained by a new general model of LysM-containing receptor complexes in which two partners form a long but off-set chitin-binding groove and are, thus, dimerized by one chitin or chitosan molecule, sharing a central GlcNAc unit with which both LysM domains interact. To verify this model and to distinguish it from earlier models, we assayed elicitor and inhibitor activities of selected partially acetylated chitosan oligomers with fully defined structures. In contrast to the initial ‘continuous groove’, the original ‘sandwich’, or the current ‘sliding mode’ models for the chitin/chitosan receptor, the here-proposed ‘slipped sandwich’ model—which builds on these earlier models and represents a consensus combination of these—is in agreement with all experimental observations.
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Barroso-Martín, Isabel, Juan Antonio Cecilia, Enrique Vilarrasa-García, Daniel Ballesteros-Plata, Carmen Pilar Jiménez-Gómez, Álvaro Vílchez-Cózar, Antonia Infantes-Molina, and Enrique Rodríguez-Castellón. "Modification of the Textural Properties of Chitosan to Obtain Biochars for CO2-Capture Processes." Polymers 14, no. 23 (December 1, 2022): 5240. http://dx.doi.org/10.3390/polym14235240.
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Three chitosans with different morphologies have been used (commercial chitosan powder, chitosan in film form and chitosan in globular form synthesized by the freeze-dried method) for the synthesis of biochars. The pyrolytic treatment has revealed that the biochar synthesized from the chitosan formed by the freeze-dried method reaches the highest CO2-adsorption capacity (4.11 mmol/g at 0 °C and a pressure of 1 bar) due to this adsorbent is highly microporous. Moreover, this biochar is more resistant to the pyrolytic treatment in comparison to the biochars obtained from the commercial chitosan and chitosan in the form of film. CO2-adsorption studies at different temperatures have also shown that the adsorption capacity diminishes as the adsorption temperature increases, thus suggesting that the adsorption takes place by a physical process.
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Razdan, A., and D. Pettersson. "Effect of chitin and chitosan on nutrient digestibility and plasma lipid concentrations in broiler chickens." British Journal of Nutrition 72, no. 2 (August 1994): 277–88. http://dx.doi.org/10.1079/bjn19940029.
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Broiler chickens were fed on a control diet based on maize and maize starch or diets containing chitin, or 94, 82 or 76% deacetylated chitin (chitosans) with different viscosities (360, 590 and 620 m Pa.s respectively) at an inclusion level of 30 g/kg. Animals had free access to feed and water for the whole experimental period. On days 10 and 18 of the experiment chickens given the control and chitin-containing diets weighed more, had consumed more feed and had lower feed conversion ratios (g feed/g weight gain) than chitosan-fed birds. Feeding of chitosan-containing diets generally reduced total plasma cholesterol and high-density-lipoprotein (HDL)-cholesterol concentrations and gave an increased HDL:total cholesterol ratio in comparison with chickens given the control and chitin-containing diets. However, no significant reductions in plasma triacylglycerol concentrations resulting from feeding of the chitosan-containing diets were observed. The reduction in total cholesterol concentration and increased HDL: total cholesterol ratio were probably caused by enhanced reverse cholesterol transport in response to intestinal losses of dietary fats. The suggestion that dietary fat absorption was impeded by the chitosans was strengthened by the observation that ileal fat digestibility was reduced by 26% in comparison with control and chitin-fed animals. In a plasma triacylglycerol response study on day 21, feeding of 94 and 76%-chitosan-containing diets generally reduced postprandial triacylglycerol concentrations compared with chickens given the chitin-containing diet. Duodenal digestibilities of nutrients amongst chickens given the chitin-containing diet were generally lower than those of control and chitosan-fed birds indicating decreased intestinal transit time. The reduced caecal short-chain fatty acid concentrations of chickens given chitosan diets compared with the control diet illustrates the antimicrobial nature of chitosan. The fact that the three chitosan-containing diets affected the registered variables similarly indicated that the level of inclusion of chitosans in the diet exceeded the level at which the effect of the different viscosities could be significant.
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Liu, Qili, Jianxin Zhang, Dong Li, Jianfeng Lang, Shasha Zai, Jianjun Hao, and Xiaohui Wang. "Inhibition of Amphiphilic N-Alkyl-O-carboxymethyl Chitosan Derivatives on Alternaria macrospora." BioMed Research International 2018 (June 11, 2018): 1–9. http://dx.doi.org/10.1155/2018/5236324.
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Cotton leaf spot (Alternaria macrospora) is a widespread disease that occurs in the main cotton-producing area of China. In managing this disease, a novel chitosan-based biopesticide, an amphiphilic N-alkyl-O-carboxymethyl chitosan derivative, was prepared. The product was selected from variations of chitosan with different molecular structures, which were obtained via a two-step reaction. First, carboxymethyl chitosans with varying molecular sizes were obtained by etherification with chloroacetic acid; then the carboxymethyl chitosan was alkylated with C4–C12 fatty aldehyde through a Schiff-base reaction. This procedure resulted in derivatives of amphiphilic N-alkyl-O-carboxymethyl chitosan, which showed strong antifungal activities against A. macrospora, and the efficacy was determined by its molecular structure.
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Vilcáez, Javier, and Tomohide Watanabe. "Inhibitory Effect of Gamma-Irradiated Chitosan on the Growth of Denitrifiers." International Journal of Microbiology 2009 (2009): 1–5. http://dx.doi.org/10.1155/2009/418595.
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In order to find an environmentally benign substitute to hazardous inhibitory agents, the inhibitory effect of -irradiated chitosans against a mixed culture of denitrifying bacteria was experimentally evaluated. Unlike other studies using pure aerobic cultures, the observed effect was not a complete inhibition but a transient inhibition reflected by prolonged lag phases and reduced growth rates. Raw chitosan under acid conditions (pH 6.3) exerted the strongest inhibition followed by the 100 kGy and 500 kGy irradiated chitosans, respectively. Therefore, because the molecular weight of chitosan decreases with the degree of -irradiation, the inhibitory properties of chitosan due to its high molecular weight were more relevant than the inhibitory properties gained due to the modification of the surface charge and/or chemical structure by -irradiation. High dosage of -irradiated appeared to increase the growth of mixed denitrifying bacteria in acid pH media. However, in neutral pH media, high dosage of -irradiation appeared to enhance the inhibitory effect of chitosan.
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de Oliveira, Ana Maria, Telma Teixeira Franco, and Enio Nazaré de Oliveira Junior. "Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation." International Journal of Polymer Science 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/853572.
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The thermal depolymerization of chitosan and alkaline deacetylation of chitin were characterized by measurement of viscosity, gel permeation chromatography (GPC), potentiometric titration (PT), and proton nuclear magnetic resonance spectroscopy (H1NMR). The depolymerization rates (DR) measured by kinematic viscosity (KV), apparent viscosity (AV), and GPC (Mw) until 4 h of treatment wereDRKV=21.9,DRAV=25.5, andDRMw=23.3% h-1and for 5 to 10 h of treatment they decreased slowly to produce ofDRKV=0.545,DRAV=0.248, andDRMw=1.11% h-1. The mole fraction of N-acetylglucosamine residuesFAof chitosans was not modified after 10 h of thermal treatment at 100°C. The initialFAvalues of chitosan without any treatment wereFAPT=0.21andFAHNMR1=0.22and of chitosan treated for 10 h wereFAPT=0.27andFAHNMR1=0.22. The variables used to characterize the depolymerization process showed a good correlation. Six hours of thermal treatment as sufficient to obtain chitosans with a molar mass 90% smaller than that of the control chitosan without treatment.
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Sánchez, Luis-Felipe, Jimmy Cánepa, Suyeon Kim, and Javier Nakamatsu. "A Simple Approach to Produce Tailor-Made Chitosans with Specific Degrees of Acetylation and Molecular Weights." Polymers 13, no. 15 (July 22, 2021): 2415. http://dx.doi.org/10.3390/polym13152415.
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Chitin is a structural polysaccharide that is found in crustaceans, insects, fungi and some yeasts. Chitin deacetylation produces chitosan, a well-studied biopolymer with reported chemical and biological properties for diverse potential applications for drug delivery, metal ion absorption, scaffolds and tissue engineering. Most known properties of chitosan have been determined from samples obtained from a variety of sources and in different conditions, this is, from chitosans with a wide range of degrees of N-acetylation (DA) and molecular weight (MW). However, as for any copolymer, the physicochemical and mechanical characteristics of chitosan highly depend on their monomer composition (DA) and chain size (MW). This work presents a simple methodology to produce chitosans with specific and predictive DA and MW. Reaction with acetic anhydride proved to be an efficient method to control the acetylation of chitosan, DAs between 10.6% and 50.6% were reproducibly obtained. In addition to this, MWs of chitosan chains were reduced in a controlled manner in two ways, by ultrasound and by acidic hydrolysis at different temperatures, samples with MWs between 130 kDa and 1300 kDa were obtained. DAs were determined by 1H-NMR and MWs by gel permeation chromatography.
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SULASTRI, EVI, YONELIAN YUYUN, NIA HERIANI, and AKHMAD KHUMAIDI. "Application of Chitosan Shells Meti (Batissa Violacea L. Von Lamarck, 1818) as Edible Film." Current Research in Nutrition and Food Science Journal 7, no. 1 (January 24, 2019): 253–64. http://dx.doi.org/10.12944/crnfsj.7.1.25.
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Edible films are thin layer films used for packaging material andformed from a mixture of polymer and plasticizer. The polymer used is chitosan obtained from shell so fmeti (Batissa violacea L. von Lamarck, 1818). This study aims to determine the characteristics of edible film and optimum concentration of chitosan and glycerol as plasticizer. Edible films were prepared in 9 formulas with variation of chitosan (1%, 2%, 3%) and glycerol (1.2; 1.5; 2 ml/g chitosan). The films were analyzed by physicalcharacterizations including organoleptic, pH, viscosity, moisture content, thickness, tensile strength, elongation, and morphology.The results showed that edible films, produced by varied concentration of chitosan and glycerol, are significantlydifferent in the characteristics of viscosity, pH, thickness, tensile strength, elongation and morphology. Chitosan1 % and glycerol (2 ml/g chitosan) was found to perform the best characteristics of film enhancing certain properties such as thickness, tensile strength, elongation, and morphology. In conclusion, chitosan from metishell can be potentially used as an edible film polymer with desirable properties.
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Román-Doval, Ramón, Sandra P. Torres-Arellanes, Aldo Y. Tenorio-Barajas, Alejandro Gómez-Sánchez, and Anai A. Valencia-Lazcano. "Chitosan: Properties and Its Application in Agriculture in Context of Molecular Weight." Polymers 15, no. 13 (June 28, 2023): 2867. http://dx.doi.org/10.3390/polym15132867.
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Chitosan is a naturally occurring compound that can be obtained from deacetylated chitin, which is obtained from various sources such as fungi, crustaceans, and insects. Commercially, chitosan is produced from crustaceans. Based on the range of its molecular weight, chitosan can be classified into three different types, namely, high molecular weight chitosan (HMWC, >700 kDa), medium molecular weight chitosan (MMWC, 150–700 kDa), and low molecular weight chitosan (LMWC, less than 150 kDa). Chitosan shows several properties that can be applied in horticultural crops, such as plant root growth enhancer, antimicrobial, antifungal, and antiviral activities. Nevertheless, these properties depend on its molecular weight (MW) and acetylation degree (DD). Therefore, this article seeks to extensively review the properties of chitosan applied in the agricultural sector, classifying them in relation to chitosan’s MW, and its use as a material for sustainable agriculture.
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Romany, Aarion, Gregory F. Payne, and Jana Shen. "Effect of Acetylation on the Nanofibril Formation of Chitosan from All-Atom De Novo Self-Assembly Simulations." Molecules 29, no. 3 (January 23, 2024): 561. http://dx.doi.org/10.3390/molecules29030561.
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Chitosan-based materials have broad applications, from biotechnology to pharmaceutics. Recent experiments showed that the degree and pattern of acetylation along the chitosan chain modulate its biological and physicochemical properties; however, the molecular mechanism remains unknown. Here, we report, to the best of our knowledge, the first de novo all-atom molecular dynamics (MD) simulations to investigate chitosan’s self-assembly process at different degrees and patterns of acetylation. Simulations revealed that 10 mer chitosan chains with 50% acetylation in either block or alternating patterns associate to form ordered nanofibrils comprised of mainly antiparallel chains in agreement with the fiber diffraction data of deacetylated chitosan. Surprisingly, regardless of the acetylation pattern, the same intermolecular hydrogen bonds mediate fibril sheet formation while water-mediated interactions stabilize sheet–sheet stacking. Moreover, acetylated units are involved in forming strong intermolecular hydrogen bonds (NH–O6 and O6H–O7), which offers an explanation for the experimental observation that increased acetylation lowers chitosan’s solubility. Taken together, the present study provides atomic-level understanding the role of acetylation plays in modulating chitosan’s physiochemical properties, contributing to the rational design of chitosan-based materials with the ability to tune by its degree and pattern of acetylation. Additionally, we disseminate the improved molecular mechanics parameters that can be applied in MD studies to further understand chitosan-based materials.
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Hemra Hamrayev and Kamyar Shameli. "Synthesis and Characterization of Ionically Cross-Linked Chitosan Nanoparticles." Journal of Research in Nanoscience and Nanotechnology 7, no. 1 (March 23, 2023): 7–13. http://dx.doi.org/10.37934/jrnn.7.1.713.
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Chitosan is an amino polysaccharide with exciting scientific uses because of its distinct structure and several various functions. High biocompatibility, strong biodegradability, and low toxicity are some of the chitosan's most notable characteristics. Chitosan holds great promise for biomedical uses including targeted delivery of drugs. Therefore, this research suggests tripolyphosphate (TPP)-based ionically cross-linked chitosan nanoparticles. XRD and FTIR analysis methods were used to characterize the acquired samples. The outcomes proved that chitosan nanoparticles have an XRD pattern similar to an amorphous polymer. Additionally, FTIR verified that the nanoparticles included chitosan ammonium groups linked to tripolyphosphoric groups of TPP.
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Reay, Sophie L., Emma L. Jackson, Daniel Salthouse, Ana Marina Ferreira, Catharien M. U. Hilkens, and Katarina Novakovic. "Effective Endotoxin Removal from Chitosan That Preserves Chemical Structure and Improves Compatibility with Immune Cells." Polymers 15, no. 7 (March 23, 2023): 1592. http://dx.doi.org/10.3390/polym15071592.
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Chitosan is one of the most researched biopolymers for healthcare applications, however, being a naturally derived polymer, it is susceptible to endotoxin contamination, which elicits pro-inflammatory responses, skewing chitosan’s performance and leading to inaccurate conclusions. It is therefore critical that endotoxins are quantified and removed for in vivo use. Here, heat and mild NaOH treatment are investigated as facile endotoxin removal methods from chitosan. Both treatments effectively removed endotoxin to below the FDA limit for medical devices (<0.5 EU/mL). However, in co-culture with peripheral blood mononuclear cells (PBMCs), only NaOH-treated chitosan prevented TNF-α production. While endotoxin removal is the principal task, the preservation of chitosan’s structure is vital for the synthesis and lysozyme degradation of chitosan-based hydrogels. The chemical properties of NaOH-treated chitosan (by FTIR-ATR) were significantly similar to its native composition, whereas the heat-treated chitosan evidenced macroscopic chemical and physical changes associated with the Maillard reaction, deeming this treatment unsuitable for further applications. Degradation studies conducted with lysozyme demonstrated that the degradation rates of native and NaOH-treated chitosan-genipin hydrogels were similar. In vitro co-culture studies showed that NaOH hydrogels did not negatively affect the cell viability of monocyte-derived dendritic cells (moDCs), nor induce phenotypical maturation or pro-inflammatory cytokine release.
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TSAI, GUO-JANE, and WEN-HUEY SU. "Antibacterial Activity of Shrimp Chitosan against Escherichia coli." Journal of Food Protection 62, no. 3 (March 1, 1999): 239–43. http://dx.doi.org/10.4315/0362-028x-62.3.239.
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The effects of cell age, reaction temperature, pH value, and salts on the inhibitory activity of shrimp chitosan (98% deacetylated) against Escherichia coli were investigated. The age of a bacterial culture affected its susceptibility to chitosan, with cells in the late exponential phase being most sensitive to chitosan. Higher temperature (25 and 37°C) and acidic pH increased the bactericidal effects of chitosan. Sodium ions (100 mM Na+) might complex with chitosan and accordingly reduce chitosan's activity against E. coli. Divalent cations at concentrations of 10 and 25 mM reduced the antibacterial activity of chitosan, in the order of Ba2+ > Ca2+ > Mg2+. Chitosan also caused leakage of glucose and lactate dehydrogenase from E. coli cells. These data support the hypothesis that the mechanism of chitosan antibacterial action involves a cross-linkage between the polycations of chitosan and the anions on the bacterial surface that changes the membrane permeability.
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Peker, Ismail, Faik N. Oktar, Murat Senol, and M. Eroglu. "An Economic Method for Chitosan Production." Key Engineering Materials 309-311 (May 2006): 473–76. http://dx.doi.org/10.4028/www.scientific.net/kem.309-311.473.
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Chitosan is a deacetylated derivative of chitin, which is a naturally abundant mucopolysaccharide, supporting the matter of crustaceans, insects, and fungi. Because of its unique properties, such as non-toxicity, biodegradability, and biocompatibility, chitosan has a wide range of applications in various fields. Increasing interest on chitosan’s usage has resulted in high consumption. Therefore, production of chitosan from essential sources with desired characteristics has become an important issue. Several methods, with different chemicals and reaction conditions, have been reported in the literature. This study aimed to shed light in several features of a very promising chitin isolation method described by Tolaimate et al. and its effect on the produced chitosan’s phisico-chemical characteristics.
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Tirado-Gallegos, Juan Manuel, Paul Baruk Zamudio-Flores, Miguel Espino-Díaz, René Salgado-Delgado, Gilber Vela-Gutiérrez, Francisco Hernández-Centeno, Haydee Yajaira López-De la Peña, María Hernández-González, J. Rodolfo Rendón-Villalobos, and Adalberto Ortega-Ortega. "Chitosan Films Obtained from Brachystola magna (Girard) and Its Evaluation on Quality Attributes in Sausages during Storage." Molecules 26, no. 6 (March 22, 2021): 1782. http://dx.doi.org/10.3390/molecules26061782.
Full textAbstract:
High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10−11 g/m s Pa) than commercial chitosans films (from 16.06 × 10−11 to 64.30 × 10−11 g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24% to 2.38%). A higher increase in hardness (from 22.32 N to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.
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Okhota, E. V., A. I. Chepkasova, E. P. Karaulova, and T. N. Slutskaya. "SUBSTANTIATION OF POSSIBILITY TO USE WASTE OF SEA CUCUMBER PROCESSING FOR PRODUCTION OF SOFT DRINKS." Izvestiya TINRO 200 (March 26, 2020): 221–28. http://dx.doi.org/10.26428/1606-9919-2020-200-221-228.
Full textAbstract:
The broth of sea cucumber was decolorized with mineral sorbents, as perlite and bentonite, and with chitosans of crab carapace and shrimp shell. The chitosans were the most effective in sorption and subsequent removal of the protein-pigment complex, providing the decolorization degree of 35–55 %. Besides, the content of glycosides in the broth was twice decreased. The amino sugars content changed in dependence on the chitosan origin: the chitosan of crab carapace did not influence on this parameter, but the chitosan of shrimp shell caused its halving. For the optimal combination of chemical compounds in the broth, the chitosan with high molecular weight (1300 kDa) extracted from crab carapace should be used for decolorizing. Preliminary fermentation of the broth with Protamex increased concentration of biologically active peptides with low molecular weight in the solution. The fermented and decolorized broth of sea cucumber has good organoleptic properties and high content of biologically active components, as glycosides, amino sugars and low molecular weight peptides, so could be used as the basis for nonalcoholic tonic drinks.
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Reis, Berthold, Konstantin B. L. Borchert, Martha Kafetzi, Martin Müller, Karina Haro Carrasco, Niklas Gerlach, Christine Steinbach, et al. "Ecofriendly Removal of Aluminum and Cadmium Sulfate Pollution by Adsorption on Hexanoyl-Modified Chitosan." Polysaccharides 3, no. 3 (August 19, 2022): 589–608. http://dx.doi.org/10.3390/polysaccharides3030035.
Full textAbstract:
The purity and safety of water as a finite resource is highly important in order to meet current and future human needs. To address this issue, the usage of environmentally friendly and biodegradable adsorbers and flocculants is essential. Chitosan, as a biopolymer, features tremendous properties as an adsorber and flocculant for water treatment. For the application of chitosan as an adsorber under acidic aqueous conditions, such as acid mine drainage, chitosan has been modified with hydrophobic hexanoyl chloride (H-chitosan) to reduce the solubility at a lower pH. In order to investigate the influence of the substitution of the hexanoyl chloride on the adsorption properties of chitosan, two chitosans of different molecular weights and of three different functionalization degrees were analyzed for the adsorption of CdSO4(aq) and Al2(SO4)3(aq). Among biobased adsorbents, H-chitosan derived from the shorter Chitosan exhibited extraordinarily high maximum adsorption capacities of 1.74 mmol/g and 2.06 mmol/g for Cd2+ and sulfate, and 1.76 mmol/g and 2.60 mmol/g for Al3+ and sulfate, respectively.
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Nasution, Darwin Yunus, Amir Hamzah Siregar, and Etika Rokhmayanti. "Determination of Maximum Adsorption Capacity of Chitosan and Carboxymethyl Chitosan on the Absorption of Metal Ions Cr (VI) Based on the Langmuir Equation." Journal of Chemical Natural Resources 6, no. 1 (May 20, 2024): 30–38. http://dx.doi.org/10.32734/jcnar.v6i1.16212.
Full textAbstract:
A study has been conducted to investigate the adsorption of chrom (VI) metal ions by hand chitosan and carboxymethyl chitosan. This research aimed to examine the adsorption capacity of chitosan and carboxymethyl chitosan and determine the applicability of the Langmuir isotherm adsorption method for adsorbing Cr (VI) metal ions utilizing these materials. Chitosan was chemically treated with a 40% NaOH solution and monochloroacetic acid, dispersed in 2-propanol at room temperature for 10 h. This reaction resulted in the formation of carboxymethyl chitosan. FT-IR analyzed the functional group of carboxymethyl chitosan. The adsorption process was conducted using a standard solution with varying concentrations of Cr6+, specifically 5, 10, 15, and 20 mg/L. The concentration of Cr6+ adsorbed was measured using an Atomic Absorption Spectrophotometer. The findings demonstrated that carboxymethyl chitosan exhibited the maximum capacity for adsorbing chrom metal ions, with a mass of 0.9179 mg/g carboxymethyl chitosan at a concentration of 20 ppm. Chrom (VI) metal ion adsorption by carboxymethyl chitosan follows the Langmuir equation with an R2 value greater than 0.9. The maximum adsorption capacity of carboxymethyl chitosan is 1.16 mg/g, which is higher compared to chitosan's capacity of only 0.60 mg/g.
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Na, Jae Sik, Sang Soon Park, Chun Ho Kim, Sang Bong Lee, and Byung Ok Jung. "Effect of Stabilization of Changing Viscosity in Chitosan Solution as a Bio-Adsorbent." Key Engineering Materials 342-343 (July 2007): 925–28. http://dx.doi.org/10.4028/www.scientific.net/kem.342-343.925.
Full textAbstract:
The emulsion stabilizing potential of chitosans was compared in the presence of organic additives. The 4 types suspension of 0.1 wt% of chitosan flocculant were obtained by mixing of chitosan colloidal dispersion with three kinds of additives; sorbic acid, benzoic acid and dibutylhydroxytoluene (BHT). The viscosity of emulsion revealed the following order of stabilizing potentials; sorbic acid > benzoic acid > BHT. As a bio-adsorbent for the treatment of biomedical wastewater, the results were capable of adsorbing more than 30% of pure chitosan. The chitosan emulsions represented that the removal efficiency were increased by COD 59.2%, BOD 70.1%, Zn 77.1%, Cu 93.7%, E. coli 99.4%. As a result of this investigation, it is remarked that the high stabilizing potential of chitosan solution is explained by higher adsorption efficiency with organics, heavy metals and microorganism, and that the effectiveness of chitosan solution for coagulating biomedical wastewater suspension could be improved due to stabilization of the viscosity in the presence of organic additives.
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Grimling, Bożena, Bożena Karolewicz, Urszula Nawrot, Katarzyna Włodarczyk, and Agata Górniak. "Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient." Marine Drugs 18, no. 12 (November 26, 2020): 591. http://dx.doi.org/10.3390/md18120591.
Full textAbstract:
Chitosans represent a group of multifunctional drug excipients. Here, we aimed to estimate the impact of high-molecular weight chitosan on the physicochemical properties of clotrimazole–chitosan solid mixtures (CL–CH), prepared by grinding and kneading methods. We characterised these formulas by infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry, and performed in vitro clotrimazole dissolution tests. Additionally, we examined the antifungal activity of clotrimazole–chitosan mixtures against clinical Candida isolates under neutral and acid conditions. The synergistic effect of clotrimazole and chitosan S combinations was observed in tests carried out at pH 4 on Candida glabrata strains. The inhibition of C. glabrata growth reached at least 90%, regardless of the drug/excipient weight ratio, and even at half of the minimal inhibitory concentrations of clotrimazole. Our results demonstrate that clotrimazole and high-molecular weight chitosan could be an effective combination in a topical antifungal formulation, as chitosan acts synergistically with clotrimazole against non-albicans candida strains.
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Sun, Su-Fang, and Yan Zhang. "A Novel Process to Prepare Chitosan Macrospheres without Shrinkage and its Application to Immobilize β-Galactosidase." E-Journal of Chemistry 6, no. 4 (2009): 1211–20. http://dx.doi.org/10.1155/2009/151727.
Full textAbstract:
A new process for the preparation of chitosan macrospheres, which was simple and practicable, was suggested in this paper and various chitosans with different molecular weight were used as materials to immobilize β-galactosidase and the chitosan macrospheres with the lowest molecular weight (500 000) was selected as enzyme immobilization carrier based on the highest enzyme activity. In order to overcome the shrinkage of chitosan during drying, the wet macrospheres obtained was treated by 30% glycerol solution for 1 h before drying and the results showed that the dried chitosan macrospheres obtained could keep almost the same structure as its wet form, which was very important for chitosan as enzyme carrier in industry. Finally, β-galactosidase from Aspergillus oryzae was immobilized on above dry chitosan macrospheres and a satisfactory result of the immobilized enzyme was obtained in enzyme activity yield, pH stability, thermal stability, operational stability, Michaelis constants Kmand the maximum velocity (Vm)