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GLUCOSAMINE. 219
Appendix to the Monosaccharides,
a. Amino-sugars.
The most important amino-sugar is the already mentioned glucosamine.
CH2OH
(/-Glucosamine (chitosamine), C6H13NO5, = /,„ "
TTJ ,
whose synthet-
Cn.1N.ri2
COH
ical preparation has been given on page 201 was first prepared by
Ledderhose J
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 Leuchs 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, (a) 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 (rf-glucosaminic
acid) is produced, and this is converted into chitaric acid, CgHioOg,
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.
* Zeitschr. f. physiol. Chem., 34.
6
Ber. d. d. chem. Gesellsch., 34.
p Mediz. Woche, 1901, No. 15; see Langstein, Ergebnisse der Physiol., I, Abt. 1, 88.
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