Two series of new chitosan derivatives were synthesized by reaction of deacetylated chitosan (CH) with propyl (CH-Propyl) and pentyl (CH-Pentyl) trimethylammonium bromides to obtain derivatives with increasing degrees of substitution (DS). The derivatives were characterized by (1)H NMR and potentiometric titration techniques and their antifungal activities on the mycelial growth of Aspergillus flavus were investigated in vitro. The antifungal activities increase with DS and the more substituted derivatives of both series, CH-Propyl and CH-Pentyl, exhibited antifungal activities respectively three and six times higher than those obtained with commercial and deacetylated chitosan. The minimum inhibitory concentrations (MIC) were evaluated at 24, 48 and 72 h by varying the polymer concentration from 0.5 to 16 g/L and the results showed that the quaternary derivatives inhibited the fungus growth at polymer concentrations four times lower than that obtained with deacetylated chitosan (CH). The chitosans modified with pentyltrimethylammonium bromide exhibited higher activity and results are discussed taking into account the degree of substitution (DS).
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http://dx.doi.org/10.1016/j.micres.2012.06.006 | DOI Listing |
Int J Mol Sci
December 2024
Liaoning Engineering and Technology Research Center for Insect Resources, College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, China.
Chitin deacetylases (CDAs) are carbohydrate esterases associated with chitin metabolism and the conversion of chitin into chitosan. Studies have demonstrated that chitin deacetylation is essential for chitin organization and compactness and therefore influences the mechanical and permeability properties of chitinous structures, such as the peritrophic membrane (PM) and cuticle. In the present study, two genes ( and ) encoding CDA protein isoforms were identified and characterized in Chinese oak silkworm () larvae.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Plant Breeding and Acclimatization Institute-National Research Institute, Radzikow, 05-870 Blonie, Poland.
The development of innovative and effective strategies to combat fungal pathogens is critical to sustainable crop protection. Fungicides have been used for over two centuries, with traditional copper- and sulfur-based formulations still in use due to their broad-spectrum, multisite mode of action, which minimizes the risk of pathogen resistance. In contrast, modern systemic fungicides, though potent, often target a single site of action, leading to the accelerated emergence of resistant fungal strains.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
School of Engineering, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK.
Chitosan is widely explored in the field of biomedicine due to its abundance and reported properties, including biocompatibility, biodegradability, non-toxicity, mucoadhesion, and anti-microbial activity. Although our understanding of the immune response to chitosan has evolved, confusion remains regarding whether chitosan is a pro- or anti-inflammatory biomaterial. Tackling this knowledge gap is essential for the translation of chitosan-based biomaterials to clinical use.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato-ku, Tokyo 108-8477, Japan.
The characteristics and prospective applications of North Pacific krill chitin and chitosan are currently unexplored, and their conventional isolation method is time- and energy-consuming. In this study, chitin and chitosan were extracted from North Pacific krill using conventional and microwave-assisted methods, followed by comprehensive characterisation and evaluation of chitosan film potential. The extracted chitin was identified as an α-polymorph, and chitosan exhibited a remarkable degree of deacetylation (90 %) in both methods.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Plant Breeding and Acclimatization Institute-National Research Institute, Radzików, 05-870 Blonie, Poland.
Chitosan (CS), derived from the partial deacetylation and hydrolysis of chitin, varies in the degree of deacetylation, molecular weight, and origin, influencing its biological effects, including antifungal properties. In plants, CS triggers immune responses and stimulates biomass growth. Previously, we found that the antifungal activity of CS was strongly dependent on its physicochemical properties.
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