A Review of Various Sources of Chitin and Chitosan in Nature

Abstract

Chitin was first discovered by its name from the Greek word "chiton", which means "mail coat". It is indeed a polysaccharide made up of naturally occurring acetyl-D-glucosamine monomers. Hatchett was the first researcher who extracted chitin from the shells of mollusks (crabs and lobsters), prawns, and crayfish in 1799. Later in 1811, Henri Braconnot discovered chitin in the cell walls of mushrooms and called it "fungine". Chitin and chitosan are abundant in the biosphere as essential components of many organisms' exoskeletons and as by-products of the global seafood industry. The biopolymer must be deacetylated before chitosan can be produced. It can also be extracted using microbes in a biological extraction procedure. The development of products that take advantage of the bioactivities of the existing primary commercial source of chitin (crustacean) has lagged expectations. Also, the disadvantages of the present commercial source such as seasonality and competition for other uses among others has been one of the driving forces towards seeking alternative sources of chitin and chitosan in nature. This review highlights some of the efforts made by environmental scholars to locate possible commercial sources of chitin and chitosan in nature over time.

High Oxidation Desulfurization of Fuels Catalyzed by Vanadium-Substituted Phosphomolybdate@Polyaniline@Chitosan as an Inorganic–Organic Hybrid Nanocatalyst

“…38,39 The spectrum of PANI (Figure 1b) shows the leading bands at 1490 and 1306 cm −1 , which may be assigned to the stretching modes of C�N− and C−N− in the quinoid and benzenoid rings of aniline, respectively. 40,41 As seen in the CH spectrum, the peaks at 880 and 1670 cm −1 corroborate the existence of −C−O−C and C�O stretching vibrations, respectively 42,43 (Figure 1c). Moreover, the characteristic peaks situated at 1592 and 2905 The UV−vis analyses of (a) V-SPM, (b) PANI, (c) CH, and (d) V-SPM@PANI@CH were conducted in the wavelength range of 200−400 nm (Figure 2).…”

“…The IR spectra of (a) pure V-SPM, (b) PANI, (c) CH, and (d) V-SPM@PANI@CH are shown in Figure perspicuously. The characteristic peaks at 1060, 954, 890, and 830 cm –1 were engendered via the stretching modes of Keggin-type vanadium-substituted phosphomolybdate anion involving ν as (P–Oa), ν as (MoOt), ν as (Mo–Ob–W), and ν as (Mo–Oc–Mo), respectively (Figure a). , The spectrum of PANI (Figure b) shows the leading bands at 1490 and 1306 cm –1 , which may be assigned to the stretching modes of CN– and C–N– in the quinoid and benzenoid rings of aniline, respectively. , As seen in the CH spectrum, the peaks at 880 and 1670 cm –1 corroborate the existence of −C–O–C and CO stretching vibrations, respectively , (Figure c). Moreover, the characteristic peaks situated at 1592 and 2905 cm –1 are corresponded to the scissoring vibrations of NH 2 and asymmetric vibrations of CH 3 , respectively.…”

Chitosan and Chitosan Nanoparticles: Parameters Enhancing Antifungal Activity

“…It consists of N-acetylglucosamine residues linked by a β 1–4 glycosidic bond. Chitosan (CS) is the product of partial deacetylation of chitin and is composed of acetylglucosamine monomers (GlcNAc) and glucosamine monomers (GlcN) ( Figure 1 ) [ 1 ]. The deacetylation process, inevitably accompanied by partial hydrolysis, gives a wide variety of CS molecules.…”

“…Chitosan has a strong antifungal effect due to its unique physicochemical properties, biodegradability, and biocompatibility [ 1 , 2 , 3 ]. Because of its biological activity, chitosan has been used to directly inhibit the growth of several fungal pathogens on crop plants [ 4 , 5 , 6 , 7 , 8 ] as well as indirectly stimulating plant defense mechanisms [ 9 , 10 ].…”

Comparative Study of the Extraction of Cu(II) and Fe(II) Ions Using Chitosan and Modified Chitosan/Polyvinylpyrrolidone Adsorptive Membranes: Adsorption, Kinetic, and Thermodynamic Study

“…The designations “chitin” and “CS” refer to various copolymer compositions that comprise anhydrous- N -acetyl-d-glucosamine and anhydrous-d-glucosamine as monomers rather than a specific compound . The primary components of insect and mollusk shells, crustacean microorganisms’ cellular walls, and crustacean microorganisms’ cellular walls are chitin and CS …”