نتایج جستجو برای: chitosan derivatives
تعداد نتایج: 121616 فیلتر نتایج به سال:
Chitosan (CS) is an abundant and renewable polysaccharide that is reported to exhibit a great variety of beneficial properties. However, the poor solubility of chitosan in water limits its applications. In this paper, we successfully synthesized single N-quaternized (QCS) and double N-diquaternized (DQCS) chitosan derivatives, and the resulting quaternized materials were water-soluble. The degr...
The goal of the present work was to study the influence of the swelling of chitosan derivatives on the enantioseparation and the separation performance recovery of chiral stationary phases (CSPs) based on these derivatives. Therefore, six chitosan bis(phenylcarbamate)-(n-octyl urea)s were synthesized, which were coated on macroporous 3-aminopropyl silica gel affording new CSPs. Most of the CSPs...
Tissue repair and regeneration is an interdisciplinary field focusing on development of biological and bioactive substitutes. Chitosan is a natural polysaccharide exhibiting excellent biocompatibility, biodegradability, affinity to biomolecules, and wound-healing activity. It can also be easily modified via chemical and physical reactions to obtain derivatives of various structures, properties,...
Chitosan has prompted the continuous movement for the development of safe and effective drug delivery systems because of its unique physicochemical and biological characteristics. The primary hydroxyl and amine groups located on the backbone of chitosan allow for chemical modification to control its physical properties. When the hydrophobic moiety is conjugated to a chitosan molecule, the resul...
The antibacterial activity of water-soluble chitosan derivatives prepared by Maillard reactions against Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Escherichia coli, Shigella dysenteriae, and Salmonella typhimurium was examined. Relatively high antibacterial activity against various microorganisms was noted for the chitosan-glucosamine derivative as compared to the acid-solu...
The potential of chitin and its derivatives mainly chitosan extends to various existing and proposed applications in an unusually large number of fields. In the present study, the prospect for using the exoskeleton of cephalopods as a raw material for chitosan manufacture was tried out. This includes the extraction of chitin from the cuttlebone (by deproteinization and demineralization) and chi...
Chitin and chitosan are considerably versatile and promising biomaterials. The deacetylated chitin derivative, chitosan is more useful and interesting bioactive polymer. Despite its biodegradability, it has many reactive amino side groups, which offer possibilities of chemical modifications, formation of a large variety of useful derivatives that are commercially available or can be made availa...
Chitosan (1) was reacted with phenylisothiocyanate in 5% AcOH/H2O to give N-phenylthiocarbamoyl chitosan (2) with a degree of substitution (DS) of N-phenylthiocarbamoyl groups of 0.86 in 87.1% yield. The following acylation of compound 2 with hexanoyl chloride in the presence of pyridine afforded 3,6-di-O-2,3-hexanoyl chitosan isothiocyanate (4a) with a DS of the isothiocyanate groups of 0.70 i...
In this paper, Fe3O4-chitosan nanoparticles were prepared by the immobilization of chitosan on the surface of Fe3O4 nanoparticles. Then, the 5-substituted hydantoins were synthesized from the condensation of aldehyde derivatives, ammonium carbonate and zinc cyanide as a well-known cyanating agent by the magnetic Fe3O4-chitosan nanoparticles under neat conditions. Fe3O4-Chitosan nanocatalyst as ...
PURPOSE Non-viral vectors have been widely proposed as safer alternatives to viral vectors, and cationic polymers have gained increasing attention because they can form self-assembly with DNA. Chitosan is also considered to be a good candidate for gene delivery systems, since it is already known as a biocompatible, biodegradable, and low toxic material with high cationic potential. However, low...
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