Untitled

Abstract

Chitosan from marine crab shell with a degree of deacetylation of 0.89 was sulfated using chlorosulfonic acid/dimethylformamide under semi-heterogeneous conditions. The resulting chitosan polysulfate exhibits high solubility in common organic solvents and, more importantly, dissolves well in water. Characteristic absorptions in the IR spectrum at 810 and 1240 cm -1 , due to sulfo groups, were assigned to C-O-S and S=O stretch bonds stretching, respectively. The elemental analysis showed C, H, N and S contents of 15.03%, 4.08%, 2.84% and 14.46%, respectively, with degree of substitution (ds.) of 1.45. The chitosan polysulfate was separated by gel filtration chromatography using Sepharose CL-6B to provide three different products with average molecular weights of 6.6, 3.5 and 1.8 x 10 4 daltons, follow with purification by FPLC. All three chitosan polysulfate preparations revealed strong anticoagulant activities. Moreover, it was shown that they inhibited Factor Xa and thrombin activity. This mechanism is the same as heparin. All results indicated that chitosan polysulfate modified by using semi-heterogeneous conditions with potent anticoagulant activity has been synthesized.

Novel biocompatible chitosan decorated single-walled carbon nanotubes (SWNTs) for biomedical applications: theoretical and experimental investigations

“…A area (iv), see ESI). 15,[25][26][27][28][29][30] w Furthermore, modification was also visible on the 1 H-NMR spectrum (Table A, see ESI)w in which new peaks at 0.9-1.1 ppm (-NH-CH 2 -(CH 2 ) 2 -CH 3 ), 1.3-1.8 ppm (-NH-CH 2 -(CH 2 ) 2 -CH 3 ) and 3.7-3.8 ppm (-NH-CH 2 -(CH 2 ) 2 -CH 3 ) were observed. The 1 H-NMR spectrum also confirmed the successful sulfation in position C6 (two broad peaks at 3.6-3.9 and 3.9-4.1 ppm).…”

Nanocomposites of Genipin‐Crosslinked Chitosan/Silver Nanoparticles ‐ Structural Reinforcement and Antimicrobial Properties

“…Chitosan is a transformed polysaccharide obtained by the deacetylation of natural chitin, which is one of the important natural polymers in the shells of crustaceans and the cell walls of many fungi. Recently, much attention has been paid to chitosan as a potential polysaccharide resource because of its excellent properties, including biocompatibility, biodegradability, haemostatic activity, antibacterial properties, low cost and ability to accelerate wound healing 27–29. However, the rapid degradation of chitosan reduces the functional longevity of its structure.…”

Antioxidant Polymers: Metal Chelating Agents

“…Of greatest potential importance are derivatives of both types formed by reaction with bi-or polyfunctional reagents, thus carrying sites for further chemical reactions [77,78]. Chitin and its derivatives have important biological properties that have potentials for a wide range of applications such as enzyme inhibitory effect [79,80], immunostimulant [81], anticoagulant [82], antimicrobial [83], anticholesteremic, anticancer [84] and wound-healing agents [85]. In practice, such reactions are carried out on native chitin or on incompletely deacetylated chitin, chitosan, so that the resulting polymer contains three types of monomeric units.…”