GLUCOSAMINE. 219 



Appendix to the M on osaccha rides. 

 a. Ammo-sugars. 



The most important amino-sugar is the already mentioned glucosamine. 



CH 2 OH 



d-Glucosamine (chitosamine), CeHiaNOo, = A^' TTT , whose synthet- 



. JN 2 



COH 



ical preparation has been given on page 201 was first prepared by 

 LEDDERHOSE 1 from chitin by the action of concentrated hydrochloric 

 acid. Recently it has been obtained as a cleavage product of several 

 mucin substances and proteins (see pages 84 and 168). Glucosamine is, 

 as E. FISCHER and LEUcns 2 have shown, a derivative of glucose or of 

 d-mannose (probably glucose), and is an a-amino-sugar. 



The free base, which can crystallize in needles, is readily soluble in 

 water giving an alkaline reaction, and quickly decomposes. The charac- 

 teristic hydrochloride forms colorless crystals which are stable in the air 

 and readily soluble in water, soluble with difficulty in alcohol, and insoluble 

 in ether. The solution is dextrorotatory, (<*) D = +70.15 to 74.64, at vari- 

 ous concentrations. 3 Glucosamine has a reducing action similar to that of 

 glucose, and gives the same osazone, but is not fermentable. With 

 benzoyl-chloride and caustic soda it gives a crystalline ester. In alkaline 

 solution it gives with phenylisocyanate a compound which can be con- 

 verted into its anhydride by acetic acid, and is used in the separation and 

 detection of glucosamine (STEUDEL). 4 On oxidation with nitric acid it 

 yields norisosaccharic acid, whose lead salt can be separated, and whose 

 salts with cinchonine or quinine are soluble with difficulty in water and can 

 also be used very successfully in the detection of glucosamine (NEUBERG and 

 WOLFF 5 ). On oxidation with bromine, chitaminic acid (d-glucosaminic 

 acid) is produced, and this is converted into chitaric acid, CeHioOe, 

 by nitrous acid. On treatment with nitrous acid glucosamine yields 

 a non-fermentable sugar called chitose. 



EHRLICH 6 has suggested a test which does not respond with the free glucos- 

 amine, but with the mucins and other protein bodies containing an acetylated 

 glucosamine. It consists in warming the substance, which has been previously 



1 Zeitschr. f. physiol. Chem., 2 and 4. 



2 Ber. d. d. chem. Gesellsch., 36. 



3 See Hoppe-Seyler-Thierfelder's Handbuch, 8, Aufl.; Sundvik, Zeitschr. f. physiol 

 Chem., 34. 



4 Zeitschr. f . physiol. Chem., 34. 



* Ber. d. d. chem. Gesellsch., 34. 



* Mediz. Woche, 1901, No. 15; see Langstein, Ergebnisse der Physiol., I, Abt. 1, 88. 



