Chitosan and chitin, characterization

Brugnerotto, J., Lizardi, J., Goycoolea, F.M., Arguelles-Monal, W., Desbrieres, J., Rinaudo, M. An infrared investigation in relation with chitin and chitosan characterization. Polymer. 42(8), 3569-3580 (2001a)... 

Many years ago chitin was seen as a scarcely appeahng natural polymer due to the variety of origins, isolation treatments and impurities, but the works of several analytical chemists and the endeavor of an increasing number of companies have qualified chitins and chitosans for sophisticated applications in the biosciences. Chemistry today offers a range of finely characterized modified chitosans for use in the biomedical sciences. Moreover, surprising roles of these polysaccharides and related enzymes are being unexpectedly discovered [351]. 

Aranaz I, Mengibar M, Harris R et al (2009) Functional characterization of chitin and chitosan. Curr Chem Biol 3 203-230... 

Purification and characterizations of extracellular chitinases from the marine bacterium Bacillus sp. LJ-25 were described by Lee et al. (2000a). The purified chitinase so obtained showed a single band on SDS-PAGE and had an MW of approximately 50 kDa. The chitinase was most active and relatively stable at a pH of 7.0. The optimum temperature for this enzyme was around 35 °C when the pH of the reaction was kept at 7.0. The effect of metal ions on chitinase activity showed that Zn2+ strongly inhibited the enzyme activity. However, Ba2+, Co2+, Mn2+, and Cu2+ showed slight inhibition of the enzyme. Substrate specificity studies indicated that colloidal chitin (a substrate of the endo type of chitinase) was efficiently degraded by the chitinase. However, chitin and chitosan were ineffectively hydrolyzed by this enzyme. This chitinase did not hydrolyze /V,iV-diacetylchitobiose, j9-nitro phenol- /V- ace tyl - (3 -1 > - g I u c o s a mine, and Micrococcus lysodeikticus cells, which are known to be the substrates of the exo type of chitinases. 

Domard, A. and Cartier, N. 1989. Glucosamine oligomers Preparation and characterization. In Chitin and Chitosan (G.T. Skjak-Braek, Anthonsen, and P. Sandford, eds), pp. 287-383. Elsevier, London. 

Characterization of potato and cork suberin Analysis of chitin and chitosan... 

Nwe N, Stevens WF, Tokura S, Tamura H (2008) Characterization of chitin and chitosan-glucan complex extracted from cell wall of fungus Gongronella butleri USDB 0201 by enzymatic method. Enzyme Microbial Technol 42 242-251... 

Characterization of Chitin and Chitosan for Medicinal Applications (Medical Devices)... 

It is necessary to prepare several tests, grouped in preliminary, conhrmatory and other tests, for characterization of chitin and chitosan used for manufacturing of medical devices [80]. European Pharmacopoeia as well as requirements of ISO... 

Aranaz, I., Mengibar, M., Harris, R., Panos, I., Miralles, B., Acosta, N., Galed, G., Heras, A. Functional characterization of chitin and chitosan. Curr. Chem. Biol. 3, 203-230 (2009a)... 

Yen, M., Yang, J., Mau, J. Physicochemical characterization of chitin and chitosan from crab shells Carbohydr. Polym. 75, 15-21 (2009)... 

In this chapter, the main characteristics of chitin and chitosan and the more convenient techniques used for their characterization will be presented together with their main physical properties. Furthermore, the materials obtained with these polysaccharides will be described. It is important to recall that chitin is a natural polymer that is also biocompatible and biodegradable, an important advantage for biomedical and pharmaceutical applications. Good film forming properties is valuable for packaging or other applications in the domain of materials. 

Abdou, E.S., Nagy, K.S.A., and Elsabee, M.Z. 2008. Extraction and characterization of chitin and chitosan from local sources. Bioresour Technol. 99 1359-1367. 

Arcidiacono, S., Lombardi, S J., and Kaplan, D.L. 1989. Fermentation, processing and enzyme characterization for chitosan biosynthesis by Mucor rouxii. In Chitin and Chitosan Sources, Chemistry, Biochemistry, Physical Properties and Applications, eds. G. Skjak-Braek, T. Anthonsen, and P. Sandford, pp. 319-332. England Elsevier Applied Sci. 

No, H.K. and Meyers, S P. 1995. Preparation and characterization of chitin and chitosan—A review. J Aquat Food Prod Technol. 4 27-52. 

Characterization of Chitin and Chitosan Films Prepared by Several Kinds... 

Characterization of Chitin and Chitosan-Poly(Vinyl Alcohol) Blend Films.102... 

The Use of Various Types of NMR and IR Spectroscopy for Structural Characterization of Chitin and Chitosan... 

IR and NMR spectroscopy are relatively easy-to-apply for a qnaUtative and comparative evaln-ation of the chemical structure and the DA determination. These techniques are nondestructive methods and do not need initial treatment such as hydrolysis, pyrolysis, and derivatization. This chapter describes the structural characterization of chitin and chitosan (as oligomers and polymers) by IR, near-IR, and various types of NMR spectroscopy techniques. This study provides information on (1) composition, sequence, and type of residues and (2) any structural changes occurring in the molecules as a result of different processes (degradation, deacetylation, and acetylation). The influences of acids, alkali, moisture, and impurities on the NMR and IR spectra of the original molecules will be also discussed. 

The chemical structure of the two polymers can be characterized by several techniques Fourier transform infrared (FTIR) nuclear magnetic resonance (NMR) x-ray diffraction (XRD) transmission electron microscopy (TEM) scanning electron microscopy (SEM) mass spectroscopy (MS) ultraviolet spectrometry (UV) and electron scanning for chemical analysis (ESCA). The chemical structure of the two polymers can be analyzed by IR, NIR, or various types of NMR spectroscopy. Determining the structure of chitin and chitosan usually requires the application of combination of various methods. The combination of IR, NIR, and various techniques of NMR give ample information on the chemical structure. IR, NIR, and various types of NMR are less sensitive than that of other quantitative analysis such as UV, HPLC, GC, and MS. 

In this chapter, the reported information on different NMR, IR, and NIR spectroscopy techniques on structural characterization and the DA determination of oligomers and polymers of chitin and chitosan have been described. The following conclusions were made from this study (1) NMR and IR are nondestructive and noninvasive methods (2) impurities (minerals, proteins, and pigments) and moisture induce interferences and difficulties to obtain accurate results. To achieve more accurate results, care must be taken to identify the peaks correspond to the impurities (3) IR and NMR... 

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