Henri Braconnot (Chitin)

History
In 1811, Henri Braconnot (Botany director at the faculty of sciences in Nancy- France) extracted chitin for the first time and named it as ‘fungine’, he noticed that it is not soluble in sulfuric acid. In 1823, Auguste Odier, a French scientist extracted chitin from cuticle of beetles and named it after the Greek word for ‘tunic’, ‘chiton’ and after that ‘chitin’ was used. In 20th century scientists studied more about polymers and their uses, and discovered useful properties. Chitin is environmentally friendly as it is non-toxic and biodegradable and possess a lot of important uses [1,2].
Commercial chitin applications increased in the 1930s and early 1940s, but sometimes it was retarded by the competition from synthetic polymers. In 1970’s, and in order to decrease improper wasting of untreated shellfish (a good source of chitin) in coastal waters, the large scale production of chitin was supported by regulations, after that chitin

γ-chitin is considered as variant of α-chitin with different packing and polarities of chitin sheets. α-chitin is the most abundant polymorph, it is found in shrimp shells, lobster and crabs tendons and shells, fungal and yeast cell walls and in insects cuticle. It is also found in or produced by various marine living organisms [6,9]. In addition, α-chitin can be prepared through results from recrystallization from solution, in vitro biosynthesis or enzymatic polymerization [18,19]. α-chitin is highly crystalline (displays orthorhombic crystals), with both intra and inter-sheet hydrogen bonding creating a tight network that interferes with the passage of solvent, these bonds involves the association of the hydroxyl-methyl groups of adjacent chains. β-chitin structure is more opened than α chitin and it is more susceptible to intracrystalline swelling, inter sheet H-bonds are not found in the structure of β-chitin [6,9]. Figure 3 shows the hydrogen bonding pattern in α and β