Chitosan is a linear polysaccharide composed of randomly distributed β-(1→4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit) . It is made by treating the chitin shells of shrimp and other crustaceans with an alkaline substance, such as sodium hydroxide. 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 percentage in commercial chitosans ranges from 60 to 100% . On average, the molecular weight of commercially produced chitosan is 3800–20,000 daltons.
Chitosan is used as medicine and in drug manufacturing. It is a fibrous substance that might reduce how much fat and cholesterol the body absorbs from foods. It also helps blood clot when applied to wounds. People use chitosan for high blood pressure, high cholesterol, obesity, wound healing, and many other purposes, but there is no good scientific evidence to support many of these uses. Chitosan supplements appear to be safe when taken for a short time, but side effects may include constipation, gas, nausea, and stomach upset. If you are allergic to shellfish, you should not take chitosan. Chitosan may interfere with how blood thinners work in your body, so if you take warfarin, talk to your doctor before taking this supplement.
