190 
CHEMISTRY: LEVENE AND LA FORGE 
ON CHONDROSAMINE 
By P. A. Levene and F. B. La Forge 
ROCKEFELLER INSTITUTE FOR MEDICAL RESEARCH. NEW YORK 
Presented to the Academy, February 8, 1915 
Theoretically there are possible as many a-amino hexoses as there 
exist hexoses, namely, eight in the i/-series, and as many in the I and 
dl-smes>. Of the eight possible amino-sugars only one has been dis- 
covered in nature, namely, glucosamine; this also was prepared syn- 
thetically by Fischer and Leuchs,^ and to it the configuration of glucose 
was ascribed. More recent investigations have shown that two expla- 
nations for the configuration of the sugar are possible: one of glucos- 
amine and the other of mannosamine, and that at present it is not pos- 
sible to give preference to either one of the two.^ 
In the course of our investigations on the structure of chondroitin 
sulphuric acid we isolated an a-amino hexose isomeric with the one 
previously described. It was named chondrosamine.^ On the basis 
of further investigation the conclusion was reached that chondrosamine 
has the configuration of either a-altrosamine or of a-allosamine. The 
grounds for the conclusion are the following: 
1 . On oxidation with bromine the amino-hexose was transformed into 
a tetroxyaminocaproic acid having [q:]'J'* = — 29.23 (glucosaminic acid 
has [ci\^ = — 14.65°). On reduction with hydroiodic acid a hydroxy- 
aminocaproic acid was obtained. The properties of this were identi- 
cal with the acid obtained on reduction of glucosaminic acid. By this 
was demonstrated that chondrosamine contained a normal carbon chain. 
2. On oxidation with nitric acid of the deaminized chondrosaminic 
acid an anhydrodicarboxylic acid (epichondrosic acid) was obtained. 
M.P. = 201-202°C., optically inactive. C = 37.5S%; H = 4.42% 
(theory, C = 37.50; H = 4.20). 
3. On oxidation with nitric acid directly of the deaminized amino- 
sugar an acid (chondrosic) was obtained, identical in composition: 
C - 37.11%; H = 4.15%; but different in properties: M.P. = 179- 
181°; = - 16.56°. 
4. On heating in a sealed tube at 150° with equal parts of hydrochloric 
and hydrobromic acid, chondrosic acid was converted into dehydromucic 
acid: C = 45.84%; H = 3.08% (theory, C = 46.16, H = 2.57). 
5. On heating at 200°C., chondrosic acid was converted into pyro- 
mucic acid. C = 53.56%; H = 3.57 (theory, C = 53.37, H = 4.14). 
M.P. = 135°C. Isosaccharic acid is converted into dehydromucic 
