Spectra chitin

Fig. 2. Spectrum of anionic isoperoxidases isolated from potato (a) crude protein extract, (b) protein fraction not adsorbed on chitin, and (c) chitin-specific peroxidises. M - protein markers.

The c.d. spectra of chitin, both in HFIP solution and as a film cast from HFIP, are shown in Fig. 21. Chitin gels have a c.d. spectrum similar to... 

Triflumuron (Alsystin , Baycidal ) [91,92], an /V-benzoyl-W-phenyl urea chitin synthase inhibitor commercialized by Bayer CropScience, is a broad spectrum insecticide that is active against chewing insects, as well as fleas and cockroaches. 

FIGURE 2.14 The first derivative UV/Vis absorption spectrum of a-chitin (100 mg/ 100 mL) dissolved in saturated solution of calcium chloride dihydrate in methanol. 

The Raman specfra of spindles are almosf identical wifh fhe spectrum of crab chitin. The close resemblance of the spectral profile between 1000... 

FIGURE 2.16 FT-IR spectra of a-chitin for chitosans of different molecular weights. The spectra of chitosans of molecular weights in the range of 1300-28,000 Da are represented by one spectrum for simplification. 

The proton nuclear magnetic resonance ( H NMR) spectrum of chitin was obtained in concentrated and deuterated hydrochloric acid (DCl) (Fig. 2.19). Chitin can be rapidly dissolved in concentrated acid after wetting in dilute acid. The assignment of the resonances and their chemical shifts (ppm) is given in Table 2.11. The NMR spectrum shows the... 

The mass spectrum (MS) of chitin was recorded using a VG Micro-mass 7070 F gas chromatography mass spectrometer imit. The electron paramagnetic resonance (EPR) spectra were recorded using a Varian EPR spectrometer. The MS recorded at a temperature of 300 °C is shown in Eig. 2.22. This temperature was used to obtain a more stable and rich fragmentation pattern. Table 2.13 presents the list of fragments that can be attributed to the ions detected in the recorded mass spectra (MS). 

TABLE 2.12 Assignments of the chemical shifts in the NMR spectrum of chitin... 

The FT-IR spectrum of ot-chitin shows two absorption bands at approximately 1625 and 1655 cm , characteristic of hydrogen-bonded amide groups. The DA of chitin can be determined by the ratios of different IR absorption bands (Fig. 2.27), as these bands disappear upon deacetylation of chitin. 

FIGURE 2.27 FT-IR spectrum of chitin together with different baselines. 

The N NMR spectrum only shows two well-separated peaks corresponding to acetamide (NH-CO-CH3) and amine (NH2) groups (Fig. 2.29B). These two major peaks have been recognized in the spectra of chitin/chitosan, and the DA was calculated according to ... 

Like cellulose, chitin is a polysaccharide for which the polarized-infrared spectrum has proved a valuable complement to x-ray data. For... 

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