Chitin treatment with

One of the simplest ways to prepare a chitin gel is to treat chitosan acetate salt solution with carbodiimide to restore acetamido groups. Thermally not reversible gels are obtained by AT-acylation of chitosans N-acetyl-, N-propionyl- and N-butyryl-chitosan gels are prepared using 10% aqueous acefic, propionic and bufyric acid as solvents for treatment with appropriate acyl anhydride. Both N- and 0-acylation are found, but the gelation also occurs by selective AT-acylation in the presence of organic solvents. 

Recently, an enzymatic method was reported to recover the three main components of industrial shrimp waste (protein, chitin, and astaxanthin) using treatments with alcalase and pancreatin. The first enzyme was more efficient in increasing the recovery of protein from 57.5 to 64.6% and of astaxanthin from 4.7 to 5.7 mg/lOO g of dry waste. 

Chitin, (CaH, 3N05)n mw (203.19)n, N 6.89%, wh solid(when pure) insol in w in solvs which dissolve cellulose decomp to glucosamine(also called chitosamine) acetic acid when boiled with coned HC1 nitrous acid converts it to chitose, a form of sugar treatment with strong alkalies gives AcOH cbitosan, a split-product of chitin (Refs 4 7)... 

Deacetylated chitin can be prepd by the method of Rigby(Ref 3) which consists of heating at 110° for 4hrs, shrimp, lobster or crab shells(previoulsy washed by successive treatments with boiling 1% NaOH soln, 5%... 

Method 6 [6,7] Decalcification is carried out by a simple treatment with 1.4 N HCl at room temperature in a plastic or wooden container. After completion of the decalcification treatment, proteins are removed using papain, pepsin or trypsin. This method is simple and suitable for the mass production of chitin with little deacetylation... 

This hypothesis could provide an explanation for the antifungal action of antibodies to CMH. Binding of antibodies to cell wall components could interfere with the biosynthesis and organization of the cell wall polymers. In Fusarium sp [51], treatment with wheat germ agglutinin (WGA), which has a known affinity for chitin, resulted in alterations in... 

Of the numerous attempts to solubilize the enzyme which synthesizes chitin, stirring with 1-butanol was the only procedure found successful. The enzyme recovered after this treatment differed from the particle-bound enzyme in that it could only catalyze the synthesis of soluble chitodextrins and, furthermore, had lost the requirement for activation by 2-acetamido-2-deoxy-D-glucose. 

The reason for these differences in properties between soluble and particulate enzyme was not elucidated. It may be postulated that the particles possibly contain two enzymes—one of these, stimulated by 2-acetamido-2-deoxy-D-glucose, is responsible for the synthesis of highly polymerized chitin, and the other catalyzes the synthesis of oligosaccharides only and does not require 2-acetamido-2-deoxy-D-glucose. If this hypothesis is correct, it would seem that the treatment with 1-butanol resulted in the solubilization of the second enzyme only. 

An alkali insoluble P-D-glucan was Isolated from the mycelium of Pyricularia oryzae P-2 which was harvested in late logarithmic phase. Protein, glycogen and heteroglycan were removed by exhaustive extraction with hot water in an autoclave at 120° and 1 N sodium hydroxide. Chitin was removed by treatment with... 

Prof. Henri Braconot, director of Botanical Garden in Nancy [France] in 1811, first isolated a fibrous substance from the cell walls of mushroom, which he called FUNGINE. Later in 1823, Odier discovered that this compound is also one of the major constituents of the exoskeleton of insects and then he renamed as CHITIN [from Greek khiton meaning tunic or envelope). Prof. C. Rouget in 1859 prepared a compound from chitin by treatment with concentrated caustic solution and observed that, unlike chitin, the resulting substance dissolved in acids. This compound was then named CHITOSAN [pronounced as kite-o-san) by Hoppe-Seller In 1894 [1, 2]. 

Figure 25.2 Schematic representation of the different steps involved in chitin/chitosan preparation procedures. In this diagram a second treatment with dilute NaOH is considered for chitin isolation in order to remove any residual protein.

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