What is the Difference Between Chitin and Chitosan?

Chitin and chitosan are both polysaccharide compounds found in nature, but they have distinct differences:

1. Chemical Structure: Chitin is an amide derivative of glucose, while chitosan is a linear polysaccharide compound. Chitin is poly-(1→4)-β-linked N-acetyl-D-glucosamine, and chitosan is poly[β-(1-4)-2-acetamido-2-amino-2-deoxy-D-glucopyranose].
2. Acetylation: Chitin has a degree of acetylation of typically 0.90, while chitosan is a fully or partially N-deacetylated derivative with a typical degree of deacetylation of more than 0.65. Chitin has no free amine groups, whereas chitosan has free amine groups.
3. Solubility: Chitosan shows better solubility than chitin, which can be dissolved in acidic aqueous solutions. Chitin can be N-deacetylated to the extent that it becomes soluble in dilute acetic and formic acids.
4. Crystallinity: Both chitin and chitosan can have different degrees of crystallinity, which is a function of the degree of deacetylation.
5. Applications: Chitin and chitosan have various applications in biomedical and pharmaceutical fields, such as tissue engineering, wound dressings, antimicrobial agents, anti-aging cosmetics, and vaccine adjuvants.

Comparative Table: Chitin vs Chitosan

Chitin and chitosan are both natural polysaccharides, but they have distinct differences in their chemical and physical properties. Here is a table comparing the key differences between chitin and chitosan:

Chitin is the main component of the exoskeletons of arthropods and is the second most common natural polymer after cellulose. Chitosan, on the other hand, is produced from treating chitin with an alkaline compound such as sodium hydroxide.