Film-forming process and biocide assessment of high-molecular-weight chitosan as determined by combined ATR-FTIR spectroscopy and antimicrobial assays

Biopolymers ◽  
2006 ◽  
Vol 83 (6) ◽  
pp. 577-583 ◽  
Author(s):  
P. Fernandez-Saiz ◽  
M. J. Ocio ◽  
J. M. Lagaron
Keyword(s):  
Molecular Weight ◽  
Ftir Spectroscopy ◽  
High Molecular Weight ◽  
Forming Process ◽  
Film Forming ◽  
High Molecular Weight Chitosan

scholarly journals Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 591
Author(s):  
Bożena Grimling ◽  
Bożena Karolewicz ◽  
Urszula Nawrot ◽  
Katarzyna Włodarczyk ◽  
Agata Górniak
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Ratio ◽  
Scanning Calorimetry ◽  
Minimal Inhibitory Concentrations ◽  
Dissolution Tests ◽  
Effective Combination ◽  
The Impact ◽  
High Molecular Weight Chitosan

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.

scholarly journals Catalytic Degradation of Chitosan by Supported Heteropoly Acids in Heterogeneous Systems

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Reaction Time ◽  
High Molecular Weight ◽  
Reaction Temperature ◽  
Water Soluble ◽  
High Catalytic Activity ◽  
High Molecular Weight Chitosan

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.

Resveratrol encapsulation in high molecular weight chitosan-based nanogels for applications in ocular treatments: Impact on human ARPE-19 culture cells

2020 ◽  
Vol 165 ◽  
pp. 804-821 ◽  
Author(s):  
Florencia Solana Buosi ◽  
Agustina Alaimo ◽  
Mariana Carolina Di Santo ◽  
Fernanda Elías ◽  
Guadalupe García Liñares ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Culture Cells ◽  
High Molecular Weight Chitosan

scholarly journals Extensively deacetylated high molecular weight chitosan from the multistep ultrasound-assisted deacetylation of beta-chitin

2016 ◽  
Vol 32 ◽  
pp. 79-85 ◽  
Author(s):  
Anderson Fiamingo ◽  
Jorge Augusto de Moura Delezuk ◽  
Stéphane Trombotto ◽  
Laurent David ◽  
Sergio Paulo Campana-Filho
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ultrasound Assisted ◽  
High Molecular Weight Chitosan

scholarly journals Changes in the Respiration, Growth, and Vitamin C Content of Soybean Sprouts in Response to Chitosan of Different Molecular Weights

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1333-1335 ◽  
Author(s):  
Young-Sang Lee ◽  
Yong-Ho Kim ◽  
Sung-Bae Kim
Keyword(s):  
Molecular Weight ◽  
Vitamin C ◽  
High Molecular Weight ◽  
Soybean Seeds ◽  
Hypocotyl Length ◽  
Molecular Weights ◽  
Soybean Sprouts ◽  
High Molecular Weight Chitosan ◽  
Chlorophyll Formation

To study the effects of chitosan on the productivity and nutritional quality of soybean (Glycine max L.) sprouts, soybean seeds were soaked in solutions containing 1,000 ppm chitosan of low (<10 kDa), medium (50 to 100 kDa), or high (>1,000 kDa) molecular weight, and the respiration, growth, and vitamin C content of the sprouts were subsequently evaluated. Sprouts treated with high molecular weight chitosan exhibited a significant increase in respiration, 5%, within 1 day of treatment. Chitosan effectively increased the growth of the sprouts: sprouts treated with high molecular weight chitosan showed increases of 3%, 1%, 3%, 1%, and 12% in the total length, hypocotyl length, root length, hypocotyl thickness, and fresh weight, respectively, as compared to a control. The growth-improving effects of chitosan were proportional to the molecular weight of the molecule used in the treatment. Chitosan treatment did not result in any significant reduction in vitamin C content or postharvest chlorophyll formation, traits that determine the nutritional and marketing values of soybean sprouts. All these results suggest that soaking soybean seeds in a solution of chitosan, especially of high molecular weight, may effectively enhance the productivity of soybean sprouts without adverse effects on the nutritional and postharvest characteristics.

New Sulfonated Polyethers and Polynaphthylimides based on TNT Derivatives

2009 ◽  
Vol 21 (5) ◽  
pp. 508-521 ◽  
Author(s):  
Alexander L. Rusanov ◽  
Ludmila G. Komarova ◽  
Elena G. Bulycheva ◽  
Margarita G. Bugaenko ◽  
Nataliya M. Belomoina
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sulfonic Acid ◽  
Ether Group ◽  
Naphthalic Anhydride ◽  
Molecular Weights ◽  
Film Forming ◽  
Sulfonated Polymers ◽  
Bridging Groups ◽  
Sulfonic Acid Groups

New sulfonated and non-sulfonated monomers — dinitro and diamino compounds — were prepared on the basis of 1,3,5-trinitrobenzene (TNB) which is the demethylation product of 2,4,6-trinitrotoluene (TNT). The sulfonated dinitrocompounds interacted with different binuclear bis-phenols under the conditions of aromatic nucleophilic nitrodisplacement reactions. Polyethers of moderate molecular weights were prepared on the basis of dinitrocompound containing electron-withdrawing 3,5-dinitrodiphenyl sulfone-4′-sulfonic acid “bridging” groups. Copolymers and blends with other sulfonated polymers were prepared to improve the film-forming properties of the polyethers developed on the basis of 3,5-dinitrodiphenyl sulfone-4′-sulfonic acid. High molecular weight sulfonated polynaphthylimides were prepared by the interaction of sulfonated diamine containing electron-donating ether group — 3,5-diaminodiphenyl ether-4′-sulfonic acid — with bis(naphthalic anhydride)s. The sulfonated polyethers and polynaphthylimides thus obtained contain sulfonic acid groups in the side chains.

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