Chitooligosaccharides (COS) are hydrolyzed products of chitosan and have been proven to exhibit various biological functions. The objectives of this study were to evaluate the anti-tumor growth, anti-metastatic potency and related pathways of COS extracted from fungi

A low-molecular weight chitosan (LMWC) with a molecular mass of 20 kDa and a chitooligosaccharide mixture (oligomixture) which is composed of sugars with a degree of polymerization (DP) of 1–6 were isolated from the chitosan hydrolysate.

Fungal chitosan B or C was prepared by alkaline N-deacetylation of crude chitin B or C for 60, 90 and 120 min, which was obtained from air-dried shiitake stipes and its antioxidant properties studied. Chitosan showed antioxidant activities of 61.6–82.4% at 1 mg/ml and showed reducing powers of 0.42–0.57 at 10 mg/ml.

Water-soluble low-molecular-weight (LMW) chitosan was prepared from enzymatic hydrolysis with efficient hemicellulase. The hydrolysates were separated by ultrafiltration membranes. A separated fraction with Mw more than 5
/103 and with a degree of deacetylation of 58% was water-soluble in the free amine form.

Chitosan and its oligosaccharides, which are known to possess multiple functional properties, have attracted considerable interest due to their biological activities and potential applications in the food, pharmaceutical, agricultural and environmental industries.

Crab shell chitosan has been used as a natural flocculant for treatment of waste-water in Japan. (CM-chitin) as an ingredient for hair and skin care products and that of nonwoven chitin fabrics as an artificial cover for burn on skin. Chitin and chitosan are usable as a functional ingredient of foods and feeds in Japan.

Candida albicans is the most frequent aetiologic agent of human and animal candidosis. In initiating the disease, the Y form often converts to M form, a pro- cess called dimorphism or dimorphic transition. Although associated with the disease, the exact role of Y-M conversion in the pathogenesis of candi- dosis is still obscure and equally obscure are the mechanisms by which the Y form transforms to the M form “in vivo”.

Oligochitosan, which has greater than 3 but less than 10 saccharide (N-acetylglucosamine or glucosamine) residues, is obtained by either chemical or enzymatic hydrolysis of chitosan. In this work, we demonstrated that oligochitosan had an in vitro stimulatory effect on the release of tumor necrosis factor-a and interleukin-1 b in macrophages.

Cellulase was used to partially hydrolyse N-acetylated chitosan. The hydrolysis process was monitored by gel permeation chromatography. Factors affecting the enzymatic hydrolysis of chitosan were studied. The degraded chitosans were characterized by X-ray diffraction, thermogravimetric analysis, differential thermal analysis, Fourier transform infrared and carbon-13 magnetic resonance spectra.

Chitooligosaccharides (COS) have been shown to regulate various cellular and biological functions. However, the effect of COS on apoptosis of hepatocellular carcinoma cells remains unclear. In this study, the activity and mechanism of COS against human hepatocellular carcinoma cells (SMMC-7721 cells) were investigated in vitro.

Water-soluble chitosan oligomer (WSCO) has been reported to have anticancer activity, immuno-enhancing effect and antimicrobial activity. However, other biological activities are unknown. Herein, we have shown that WSCO is able to inhibit proliferation of human leukemia HL-60 cells and induce these cells to differentiate.

Water-soluble low-molecular weight chitosan (LMWC) and chitooligosaccharides (COs) were obtained from chitosan (16% Nacetylation) by depolymerization induced by potassium persulfate under nitrogen atmosphere for 2 h.

Chitin, colloidal chitin and water-soluble chitosan were hydrolyzed by crude enzyme solution produce by Bacillus amyloliquefaciens V656. The hydrolysates with 12 h hydrolysis contained optimal (GlcNAc)6 and showed higher antitumor activity.

Chitin is the second most abundant natural biopolymer after cellulose. The chemical structure of chitin is similar to that of cellulose with 2-acetamido-2-deoxy-b-d-glucose (NAG) monomers attached via b(1!4) linkages. Chitosan is the deacetylated (to varying degrees) form of chitin, which, unlike chitin, is soluble in acidic solutions. Application of chitinous products in foods and pharmaceuticals as well as processing aids has received considerable attention in recent years as exotic synthetic compounds are losing their appeal.

Water-soluble chitosan derivatives, having various degrees of substitution with disaccharide (DS 20–30%, 40–50%, 60–70%), were prepared by reductive alkylation of a-chitosan with lactose, maltose or cellobiose. Antioxidative activities were determined in the present study, including radical scavenging effect for a,a-diphenyl-b-picryl-hydrazyl (DPPH) radicals, superoxide anion radicals, hydrogen peroxide and copper ion chelating ability of these chitosan derivatives.

Oligo-N-acetylglucosamine (OAG) is a hydrolyzed derivative of chitin that has been used as a sweetener in foods. Since, no information has been published about the safety of OAG, a 90-day feeding study was conducted, using F344 Fischer rats of both sexes, to characterize and evaluate the toxicity of OAG, and the results of the study are presented here.

Chitosan is a partially deacetylated polymer obtained from the alkaline deacetylation of chitin which is a glucose-based unbranched polysaccharide widely distributed in nature as the principal component of exoskeletons of crustaceans and insects as well as of cell walls of some bacteria and fungi.