Deacetylation degree

Takahashi, T., Imaia, M., Suzukia, I., and Sawai, J. (2008). Growth inhibitory effect on bacteria of chitosan membranes regulated by the deacetylation degree. Biochem. Eng.. 40, 485-491. 

Nakamura, F., et al. 1992. Lysozyme-catalyzed degradation properties of the conjugates between chitosans having some deacetylation degrees and methotrexate. Yakuzaigaku 52 59. 

Chitosan is generally considered nontoxic, with the rare reported toxicity explained by Koping-Hoggard et al. as a result of impurities [94]. In their study conducted with ultrapure chitosan, transfection efficiency of 293 cells was shown to be dependent on the polyplex stability, which in mm was dependent on the deacetylation degree of chitosan. A deacetylation degree of at least 65% was... 

Chitosan CHITON Co. Ltd., Gdynia, Poland), having a deacetylation degree of 83% and viscosity (1% water solution of acetic acid, pH 3.5—4) of 20 mPas, was deposited on wool fabric pre-treated with enzymes using the pad-dry-fix method [19],... 

The ability of chitosan to form complexes with nucleic acids is highly dependent on its structural characteristics. Indeed, the deacetylation degree (i.e., the percentage of deacetylated primary amine groups along the macromolecular chain)... 

Yang J, Tian F et al (2008) Effect of chitosan molecular weight and deacetylation degree on hemostasis. J Biomed Mater Res B Appl Biomater 84B 131-137... 

Minagawa T, Okamura Y et al (2007) Effects of molecular weight and deacetylation degree of chitin/chitosan on wound healing. Carbohydr Polym 67 640-644... 

Chitosan is a nontoxic and biocompatible linear polysaccharide derivate from chitin. Chitin is found in the exoskeleton of crustaceans, in fungal cell wall, and in some biomaterials. The partial deacetylation of chitin, in the presence of hot alkali, leads to the formation of chitosan. Chitosan (Figure 31.8) is formed by 80% p-(l,4)-2-amino-2-deoxy D-glucose and 20% p-(l,4)-2-acet-amido-2-deoxy-D-glucose repeating units. Unlike insoluble chitin, chitosan is soluble in acid solution, conditions that lead to the protonation of amino groups that are responsible for its polyelectrolyte character. Both deacetylation degree (DD) and molar mass have been shown to influence properties of chitosan in solution. " ... 

Z. Dos Santos, A. Caroni, M. Pereira, D. da Silva, J. Fonseca, Determination of deacetylation degree of chitosan a comparison between conductometric titration and CHN elemental analysis, Carbohydr. Res. 344 (2009) 2591-2595. 

X. Jiang, L. Chen, W. Zhong, A new linear potentiometric titration method for the determination of deacetylation degree of chitosan, Carbohydr. Polym. 54 (2003) 457-463. 

Because vaccines alone cannot be sufficiently taken up after mucosal administration, they need to be co-administered with penetration enhancers, adjuvants, or encapsulated in microparticles. Chitosan particles, powders, and solutions are promising candidates for mucosal vaccine delivery. The aspecific adjuvant activity of chitosans seems to be dependent on the deacetylation degree and the type of formulation. 

Chitin, Chitosan, Demineralization, Deproteinization, Deacetylation, Degree of acetylation. Metal ions complexation. Polyelectrolyte complex. Biomaterial, Rocculation, Antimicrobial activity... 

Tobacco is an important economic crop and a model plant for research. Many reports reveal that CTS can induce tobacco s resistance to tobacco mosaic virus (TMV), tobacco necrosis virus (TNV), and Phytophthora parasitica nicotianae. For example. Falcon studied the effect of different sizes and deacetylation degrees of chitosan derivatives on tobacco protection against P. parasitica (Falcon et al. 2008). The result of their experiment showed that different chitosans have distinct effects on this disease control though less acetylated chitosan are better for inhibition of P. parasitica... 

Different members of CTS have different effect on plant protection. Aiming at different diseases, the most effective concentration, polymerization degree, and deacetylation degree of CTS are different. This phenomenon originates from the distinct action mechanism of different plant-pathogen interaction. 

X. Zhou, M. Kong, X.J. Cheng, C. Feng, J. Li, J.J. Li, and X.G. Chen, In vitro and in vivo evaluation of chitosan microspheres with different deacetylation degree as potential embolic agent, Carbohydr. Polym., 113,304-313,2014. 

Materials-. PVC pellets, extrusion medical-grade RB1/T3M of 1.25 g cm density, were obtained from ModerrPlast (Italy) and used as received. Pectin from apple, (BioChemika, with esterification of 70-75%), acrylic acid (AA) (99.0%, anhydrons), and V-(3-dimethyl aminopropyl)-V -ethyl carbodiimide hydrochloride (EDAC, 98.0%) were supplied by Fluka (USA). Chitosan from crab shells with meditun molecttlar weight and deacetylation degree of 75-85%. 

In order to modify there were used three chitosan brands, varied by deacetylation degrees (DD) and molecular masses (MM). DD was evaluated by acid-base titration with potentiometric definition of equivalence (Table 2.1), and was calculated with the formula [15] ... 

LDPE 10803-020 (90,000 molecular weight, 53% crystallinity degree, and 0,917 g/sM density) and chitosan samples of Bioprogress Ltd. (Russia) obtained by alkalinedeacetylation of crab chitin (deacetylation degree 84%), and M = 115000 were used as components for producing biodegradable polymer films. 

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