Chitin

About: Chitin is a research topic. Over the lifetime, 6590 publications have been published within this topic receiving 253993 citations.

A Review of the Antimicrobial Activity of Chitosan

Abstract: Chitosan, a versatile hydrophilic polysaccharide derived from chitin, has a broad antimicrobial spectrum to which gram-negative, gram-positive bacteria and fungi are highly susceptible. In the current review, three possible and accepted antimicrobial mechanisms for chitosan are presented and briefly discussed. The activity dependence on polymeric molecular weight (MW) and degree of acetylation (DA) are described. The chitosan minimum inhibitory concentrations (MIC) are summarized according to recent data found in the literature. The potential to improve inhibitory growth of bacteria by using water soluble chitosan derivatives is also discussed. The data indicate that the effectiveness of chitosan varies and is dependent on species of target microorganisms.

The structure and synthesis of the fungal cell wall.

Abstract: The fungal cell wall is a dynamic structure that protects the cell from changes in osmotic pressure and other environmental stresses, while allowing the fungal cell to interact with its environment. The structure and biosynthesis of a fungal cell wall is unique to the fungi, and is therefore an excellent target for the development of anti-fungal drugs. The structure of the fungal cell wall and the drugs that target its biosynthesis are reviewed. Based on studies in a number of fungi, the cell wall has been shown to be primarily composed of chitin, glucans, mannans and glycoproteins. The biosynthesis of the various components of the fungal cell wall and the importance of the components in the formation of a functional cell wall, as revealed through mutational analyses, are discussed. There is strong evidence that the chitin, glucans and glycoproteins are covalently cross-linked together and that the cross-linking is a dynamic process that occurs extracellularly.

Chitin metabolism in insects: structure, function and regulation of chitin synthases and chitinases

Abstract: Chitin is one of the most important biopolymers in nature. It is mainly produced by fungi, arthropods and nematodes. In insects, it functions as scaffold material, supporting the cuticles of the epidermis and trachea as well as the peritrophic matrices lining the gut epithelium. Insect growth and morphogenesis are strictly dependent on the capability to remodel chitin-containing structures. For this purpose, insects repeatedly produce chitin synthases and chitinolytic enzymes in different tissues. Coordination of chitin synthesis and its degradation requires strict control of the participating enzymes during development. In this review, we will summarize recent advances in understanding chitin synthesis and its degradation in insects.

Chitin and Chitosan: Functional Biopolymers from Marine Crustaceans

Abstract: Chitin and chitosan, typical marine polysaccharides as well as abundant biomass resources, are attracting a great deal of attention because of their distinctive biological and physicochemical characteristics. To fully explore the high potential of these specialty biopolymers, basic and application researches are being made extensively. This review deals with the fundamental aspects of chitin and chitosan such as the preparation of chitin and chitosan, crystallography, extent of N-acetylation, and some properties. Recent progress of their chemistry is then discussed, focusing on elemental modification reactions including acylation, alkylation, Schiff base formation and reductive alkylation, carboxyalkylation, phthaloylation, silylation, tosylation, quaternary salt formation, and sulfation and thiolation.