The polysaccharide, chitin, is the main component of crab shells, which is an abundant biomass. But it has poor solubility, so it is rarely used. Recently, a mechanical treatment technique for converting chitin into "nano-chitin" has been developed. Nanochitin is a fine fibrous substance with a width of about 10 nm and uniformly dispersible in water, so it is easy to process. Since it is also possible to search for functions, various functions have been clarified. Nanochitin has an effect on the skin, an effect associated with oral administration, and an effect on plants sprayed with it. It is expected that the utilization of the new materials derived from these unused resources will be promoted by clarifying unknown potential functions. ...and more
Enzymatic methods and chemical methods are two major methodologies for the synthesis of oligosaccharides. The enzymatic method using glycosyl transferase and/or glycosidase is useful for synthesizing oligosaccharides without introduction of protecting groups of hydroxyl groups. By contrast, the chemical method is based on techniques of synthetic organic chemistry. Thus, it is necessary to protect and deprotect reactive functional groups; however, both natural and unnatural oligosaccharides can be prepared. To synthesize these oligosaccharides, a number of building blocks have been developed and a variety of activation methods have also been reported for each of the building blocks. In this article, the electrochemical glycosylation of thioglycosides, which are widely used for chemical synthesis of oligosaccharides, is introduced. Although thioglycosides are stable and easy to handle, they can be selectively activated under electrochemical conditions. ...and more
Chitin and chitosan, the structural polysaccharides that support the exoskeletons of marine organisms such as shrimp and crabs, are the second most abundant biomass after cellulose, but are yet to be fully utilized as natural resources. Various approaches to create high value-added materials using chitin and chitosan have been evaluated, and potential strategies for giving such materials greater functionality include chemical modification and increasing the complexity of shape or structure. In this paper, I will describe a method for preparing a new functional material by forming chitosan into microparticles and combining them with an inorganic material, calcium carbonate. ...and more
Various biological functions of chitin and chitosan, polysaccharides contained in crab shells, are known. Many studies conducted during the past 50 years have indicated the efficiencies of chitin and chitosan for wound healing. At present, wound dressings made from chitin are also used in the medical field. Here, the wound-healing effects of chitin and chitosan are explained. ...and more
The natural polysaccharides chitin and chitosan are mucopolysaccharides that are extracted mainly from crab shells and shrimp shells. Both chitin and chitosan have high affinity to the living body and have been extensively studied in various fields. They also have interactions with microorganisms and thus research extends to the agricultural and food realms all over the world. Chitin and chitosan are each found not only in solution form, but also in the form of fibers, porous beads, and sponges, depending on the usage. As the research on chitin and chitosan nanofibers is progressing with cutting-edge technology, the effects of size and specific surface area on expanding the possibilities of application are highly expected. ...and more
