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( 1 1 ON DROITIN-SULPHURIC ACID. 547
account of the further decomposition of this last body, sulphuric acid
and a reducing substance are forme 1.
Chondromucoid is a white, amorphous, acid-reacting powder which
is insoluble in water, but dissolves easily on the addition of a little
alkali. This solution is precipitated by acetic acid in great excess and
by small quantities erf mineral acids. The precipitation may be retarded
by neutral sails or by ehondroitin-sulphuric acid. The solution con-
taining NaCl and acidified with HC1 is not precipitated by potassium
ferrocyanide. Precipitants for chondromucoid are alum, ferric chloride,
sugar of lead, or basic lead acetate. Chondromucoid is not precipitated
by tannic acid, and it may by its presence prevent the precipitation
of gelatin by this acid. It gives the usual color reactions for proteins,
namely, with nitric acid, with copper sulphate and alkali, with Mil-
lion’s and Adamkiewicz-Hopkins’ reagents.
Chcaidroitin-sulphuric Acid, chondroitic acid. This acid, which
was first prepared pure, from cartilage, by C. Morner and identified
by him as an ethereal sulphuric acid, occurs, according to Morner, in
all varieties of cartilage and also in the tunica intima of the aorta and
as traces in the bone substance. ’ K. Morner x
has also found it in the
ox-kidney and in human urine as a regular constituent. Its occurrence
in amyloid, as mentioned on page 173, has been disputed by Hanssen.
In the opinion of Levene,2
the glucothionic acid which is prepared from
tendon mucoid, and which gives the orcin reaction for glucuronic acid,
and yields furfurol on distillation with hydrochloric acid, is not identical
with the ehondroitin-sulphuric acid, but is probably related thereto.
Chondroitin-sulphuric acid has the formula C18H27NSO17, accord-
ing to Schmiedeberg.3
As primary products this acid yields, on
cleavage, sulphuric acid and a nitrogenous substance, chondroitin, accord-
ing to the following equation:
C18H27NSO17+H2O = H2S04+Ci8H27NOi4.
Chondroitin, which is similar to gum arabic, and which is a monobasic
acid, yields acetic acid and a new nitrogenous substance, chondrosin,
as cleavage products, on decomposition with dilute mineral acids:
C 18 H27NOi4+3H20 = 3C2H402+Ci2H2iN01 i.
Chondrosin, which is also a gummy substance soluble in water, is a
monobasic acid and reduces copper oxide in alkaline solutions even
1
C. Morner, 1. c, and Zeitschr. f. physiol. Chem., 20 and 23; K. Morner, Skand.
Arch. f. Physiol., 6.
2
Zeitschr. f. physiol. Chem., 39.
* Arch. f. exp. Path. u. Pharm., 28.
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