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INOSINIC AND GUANYLIC ACIDS. 183
On hydrolysis it yields phosphoric acid, hypoxanthine and pentose,
according to the equation:
CiaH18N4POiB+2HjO=H3P04+C8H4N40+C5HioO«.
The pentose, whose somewhat disputed nature has been discussed
on page 178, is combined with hypoxanthine in a glucoside-like com-
bination forming the pentoside inosine, which, according to Levene and
Jacobs, is combined with the phosphoric acid, like an ester by means
of the 5-carbon atom of the pentose (ribose).
Inosinic acid is amorphous, syrupy, readily soluble in water and pre-
cipitable by alcohol. It is lavo-rotatory; for the Ba salt containing
hydrochloric acid Neuberg and Brahn found (a) D =— 18.5° at 10° C.
It gives several crystalline salts among which the barium salt, which is
soluble with difficulty in water, must be mentioned.
In regard to the preparation of this acid we must refer to the works
of Haiser, Neuberg and Erahn, Levexe and Jacobs mentioned in
footnote 5, page 182.
Guanylic acid. This acid, which was first prepared by Bang from
the pancreas has also been found by Jones and Rowxtree in the spleen
and by Levexe and Mandel ’ in the liver. As cleavage products it yields
guanine, pentose and phosphoric acid and therefore its simplest formula
is (’10H14N5PO8. This formula is accepted also by Steudel and Brigl
and by Levexe and Jacobs, while Baxg basing his views on the results
of elementary analysis gives the formula C44H6GN20P4O34. Accord-
ing to this formula the acid would contain besides, guanine, pentose and
phosphoric acid also an unknown residue, C4H10O2, and according to Bang
is not a simple nucleic acid but would occupy an intermediary position
between the inosinic acid and the thymus nucleic acid. In opposition
to this it must be remarked that Levene and Jacobs 2
have recently
prepared the crystalline brucine salt of the acid and the analysis of this
salt as well as the barium salt substantiates the first mentioned, simple
formula. In regard to the pentose of guanylic acid see page 178.
The acid first described by Bang, the /3-acid, is soluble with great diffi-
culty in cold water and rather readily soluble in boiling water. It is easily
precipitated by acetic acid from the solution of the alkali combination
in water. The /3-acid may, according to Bang, be derived from another
guanylic acid, the a-guanylic acid, by the action of the alkali. The
1
Banc, Zeitschr. f. physiol. Chem., .26; with Raas-hou, Hofmeister’s Beitrage. 4;
Jones and Rowntree, Journ. of biol. chem., 4; Levene and Mandel, Bioehem. Zeitschr.
10.
:
Steudel and Brigl, Zeitschr. f. physiol. Chem., 68; Bang, ibid., 69 and Bioch.
Zeitschr., 26; Levene and Jacobs, Journ. of biol. Chem., 12.
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