Is Chitosan a New Panacea? Areas of Application

Abstract

Chitin is a big molecule composed of -beta-1,4-N-acetylglucosamine (GlcNAc) monomers. There are three forms of chitin: , , and chitin. The -form, is mainly obtained from crab and shrimp. Both and chitin/chitosan are commercially available [5]. Sources of chitinIn the book "Chitin" published by Muzarelli in 1977, we can find a complete list of organisms that contain chitin: Fungi, Algae, Cnidaria (jellyfish), Aschelminthes (round worm), Entoprocta, Bryozoa (Moss or lace animals, Phoronida (Horseshoe worms), Brachiopoda(Lamp shells), Echiruda, Annelida (Segmented worms), Mollusca, Arthropoda and Ponogophora [6]). Herring, P.J in 1979 wrote that chitin is the main component of arthropod exoskeletons, tendons, and the linings of their respiratory, excretory, and digestive systems, as well as insects external structure and some fungi. It is also found in the reflective material (iridophores) of both epidermis and eyes of arthropods and cephalopods (phylum: Mollusca) and the epidermal cuticle of the vertebrate Paralipophrys trigloides (fish) is also chitinous [7,8]. The main commercial sources of chitin are the shell wastes of shrimp, lobsters, crabs and krill. There are three forms of chitin: , , and chitin. The -form, is composed of alternating antiparallel polysaccharide strands and is mainly obtained from crab and shrimp. -Chitin is by far the most abundant; it occurs in fungal and yeast cell walls, krill, lobster and crab tendons and shells, shrimp shells, and insect cuticle. The rarer -chitin is composed of parallel strands of polysaccharides, is found in association with proteins in squid pens [9,10] and in the tubes synthesized by pogonophoran and vestimetiferan worms [11,12]. It also occurs in aphrodite chaetae [13] as well as in the lorica, built by some seaweeds or protozoa [14,15,16]. And 2 parallel chains alternating with an antiparallel strand constitute gamma chitin and are found in fungi [15].

Comparing the effects of glazing and chitosan-based coating applied on frozen salmon on its organoleptic and physicochemical characteristics over six-months storage

“…Chitosan can be used as an edible coating or film and is one of the most important derivatives of chitin. Chitosan can be defined as a copolymer that is composed by N-acetyl-D-glucosamine and Dglucosamine units, which can be distributed throughout the biopolymer either randomly or in blocks, these units are combined by b-(1,4) glucosidic linkages thus forming a long chain linear polymer (Castro and Paulín, 2012;Chen, 2008;Singh and Kumari, 2012). Chitosan is a biomolecule with great potential, presenting properties such as biocompatibility and biodegradability, together with its anti-viral, anti-fungal and anti-microbial activities (Kim, 2014).…”

Selected analyses of chitosan from dietary supplement on market: Development of modified methods for degree of deacetylation determination

“…Objavljeni su brojni pregledni radovi i poglavlja u monografijama koji prikazuju svojstva i različite primene hitozana [5][6][7][8][9]. Nedavno su publikovane i dve monografije [10,11].…”

Drug Carrier Systems Using Chitosan for Non Parenteral Routes

“…Although it is much less common than the natural occurrence of chitin, it is possible to obtain chitosan directly from a natural source, e. g, the structure of certain fungi [10]. However, chitosan is generally produced by chemical processes that involve the alkaline deacetylation of chitin aided by thermochemical conditions or by enzymatic hydrolysis in presence of a chitin deacetylase [2,6,11].…”

“…The two kind of D-glucosamine residues are linked by β(1→4)-glycosidic bonds. It is accepted chitosan is composed predominantly of the deacetylated form of D-glucosamine [1,2,4,6,7,[11][12][13]. The Figure 1 represents the chemical structure of chitin and chitosan.…”