Glucosamine Hydrochloride

Submitted by Earl R. Purchase and Charles E. Braun. Checked by H. R. Snvdee and Nelson R. Easton. 

Two hundred grams of eleaned and dried crab shells (Note 1) ground to a fine powder is placed in a 2-1. beaker, and an excess of dilute (approximately 6 N) commercial hydrochloric acid is added slowly to the powdered material until no further action is evident. Much frothing occurs during the addition of the acid, and care must be exercised to avoid loss of material due to foaming over the sides of the beaker. After the reaction has subsided, the reaction mixture is allowed to stand from 4 to 6 hours to ensure complete removal of calcium carbonate. The residue is then filtered, washed with water until neutral to litmus, and dried in an oven at 50-60°. The weight of dried chitin is usually about 70 g., but with some lots of crab shells it may be as low as 40 g. 

To 40 g. of dry chitin in a 500-ml. beaker is added 200 ml. of concentrated hydrochloric acid (c.p., sp. gr. 1.18), and the mixture is heated on a boiling water bath for 2.5 hours with continuous mechanical agitation. At the end of this time solution is complete, and 200 ml. of water and 4 g. of Norite are added. The beaker is transferred to a hot plate, and the solution is maintained at a temperature of about 60° and is stirred continuously during the process of decolorization. After an hour the solution is filtered through a layer of a filter aid such as Filter-Cel. The filtrate is usually a pale straw color however, if an excessive color persists, the decolorization may be repeated until the solution becomes almost colorless. The filtrate is concentrated under diminished pressure at 50° until the volume of the solution is 10-15 ml. The white crystals of glucosamine hydrochloride are 

The product is pure enough for most uses. If a purer product is desired, the crystals may be dissolved in the minimum amount of boiling water and treated with Norite. The resulting solution is filtered and added to a large excess of 95% alcohol and stirred vigorously for several hours. The product is collected after 4 to 6 hours. An appreciable amount of the d-form of the amino sugar remains dissolved in the alcohol and may be precipitated by adding ether. 

The cleaned and dried crab shells were obtained from Carter and Lanhardt Company, Eleventh and Main Avenue, S.W., Washington, D. C. 

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The preparation of glucosamine hydrochloride from lobster shells and crab shells by essentially this method has been reported by Irvine, McNicoll, and Hynd and Hudson and Dale. Other methods involving the use of cicad larvae shells and shrimp shells ls also have been reported. 

Amino-sugars and Related Compounds. Part I. The Deamination of D-Glucosamine Hydrochloride, B. C. Bera, A. B. Foster, andM. Stacey,/. Chem. Soc., (1956) 4531-4535. 

QH13NO5 3416-24-8) see Metrizamide a-D-glucosamine hydrochloride (QH14CINO5 14131-62-5) see Glucaffletacin glucoscillaren A... 

O-Methyl-D-glucosamine Hydrochloride (2-Amino-2-deoxy-6-0-methyl-... 

N-tert-Butoxycarbonyl-L-serinal from D-Glucosamine Hydrochloride. T. Henk, T. Kolter, and A. Giannis, Institut fOr Organische Chemie und Biochemie der Universitat Bonn, Gerhaid-Domagk-Str. 1,... 

The reaction of D-glucosamine hydrochloride in an aqueous acetone solu-... 

D-Glucosamine hydrochloride (25 g.) and 6.1 g. of sodium carbonate are dissolved in 50 ml. of water. Then, 25 ml. of ethyl acetoacetate is added, followed by enough acetone to make the liquid homogeneous. The mixture is kept for four days and is then evaporated to dryness under diminished pressure. The residue is recrystallized from water, with treatment with Norit, and the crystals are dried over anhydrous calcium chloride yield, 10.8 g. m. p., 141-142°.58... 

Aldose (D-xylose, o-galactose, o-mannose, D-2-deoxyglucose, D-glucosamine hydrochloride) (11.1 mmol)... 

For the synthesis of 2-aminogluconic acid, the starting glucosamine hydrochloride was first neutralized by 1 m NaOH before starting the enzymatic oxidation. The insoluble product was recovered by concentration of the reaction medium and filtration. 

Figure 6.58 Schiff base catalyst 42 and glucosamine hydrochloride as starting material for the synthesis of saccharide-based catalyst 198.

Materials. Imidazole, benzimidazole, and glucosamine hydrochloride were obtained from the Eastman Kodak Co., and used without further purification, after drying for several days over anhydrous calcium chloride. Stock solutions of nickel nitrate and nickel chloride were analyzed by precipitation with dimethyl-glyoxime. Stock solutions of cadmium nitrate were analyzed gravimetrically by conversion to cadmium sulfate. 

Measurement. Rotations were measured with a Rudolph Model 200 photoelectric polarimeter operating from a sodium vapor lamp. Water was circulated through 20-cm. tubes with glass end plates, from a bath maintained at 25.0° 0.1°. The runs on the mutarotation of D-glucose showed excellent first-order dependence over two half lives. In studies on the mutarotation of glucosamine hydrochloride in the presence of varying concentrations of sodium hydroxide and metal salt, it was necessary to add the alkali first, then the metal salt, to avoid precipitation. 

The catalysis of mutarotation of glucosamine hydrochloride involves an intramolecular mechanism, and so the catalytic coefficient of glucosamine. fcc,iNH2> must have the dimension, min.-1, instead of liters/mole min. The total rate is then... 

Preparation 418.—Glucosamine Hydrochloride [.Hydrochloride of 2-Amdno-3 4 5 Q-tetrol-hexanal- (1)]. 

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