product name: chitosan

other name: poliglusam; deacetylchitin; poly-(d)glucosamine 

appearance: white powder

specifications: 85%,90%,95% degree of deacetylation 

test method: hplc 

chemspider: 64870

cas no.:9012-76-4

structural formula:

introduction

chitosan is a linear polysaccharide composed of randomly distributed β-(1-4)-linked d-glucosamine (deacetylated unit) and n-acetyl-d-glucosamine (acetylated unit). off-white, innocuous, flavorless, amorphous and semitransparent solid, soluble in acid, insoluble in water and alkalis or ordinary organic solvents, decomposed at 185°c.

manufacture and properties

chitosan is produced commercially by deacetylation of chitin, which is the structural element in the exoskeleton of Crustaceans (such as crabs and shrimp) and cell walls of fungi. the degree of deacetylation (%dd) can be determined by nmr spectroscopy, and the %dd in commercial chitosans is in the range 60–100%. on average, the molecular weight of commercially produced chitosan is between 3800 to 20,000 daltons. a common method for the synthesis of chitosan is the deacetylation of chitin using sodium hydroxide in excess as a reagent and water as a solvent. this reaction pathway, when allowed to go to completion (complete deacetylation) yields up to 98% product.

the amino group in chitosan has a pka value of ~6.5, which leads to a protonation in acidic to neutral solution with a charge density dependent on ph and the %da-value. this makes chitosan water soluble and a bioadhesive which readily binds to negatively charged surfaces such as mucosal membranes. chitosan enhances the transport of polar drugs across epithelial surfaces, and is biocompatible and biodegradable. purified qualities of chitosans are available for biomedical applications.

chitosan and its derivatives such as trimethylchitosan (where the amino group has been trimethylated) have been used in non-viral gene delivery. trimethylchitosan, or quaternised chitosan, has been shown to transfect breast cancer cells; with increased degree of trimethylation increasing the cytotoxicity and at approximately 50% trimethylation the derivative is the most efficient at gene delivery. oligomeric derivatives (3-6 kda) are relatively non-toxic and have good gene delivery properties.

application:

widely used in the following industries: pharmaceuticals, food, health care, textile , dyeing and printing, leather, coating, tobacco, plastics, cosmetics, feed, color film, paper making, bioengineering, agriculture protecting and sewage treatment etc.

quality index: