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448 THE LIVER.
LiFSCHtJTz’s 1
Reaction. Dissolve a few milligrams of cholesterin
in 2-3 cc. glacial acetic acid, add a little benzoylsuperoxide thereto, and
boil once or twice. On adding 4 drops concentrated sulphuric acid to
the cooled solution and shaking, a pure green coloration is obtained,
which changes immediately into blue or with violet-red as an intermediary
color. An absorption-band is formed between C and d, and a broad band
at D. In this reaction an oxidation of the cholesterin occurs, and Lif-
schutz 2 therefore uses the glacial acetic acid-sulphuric acid reaction
(color and spectrum) for the detection of oxidation products of choles-
terin in blood and tissues.
Pure, dry cholesterin when fused in a test-tube over a low flame with two or
three drops of propionic anhydride yields a mass which on cooling is first violet,
then blue, green, orange, carmine-red, and finally copper-red. It is best to re-fuse
the mass on a glass rod and then to observe the rod on cooling, holding it against
a dark background (Obermuller).3
Schiff’s Reaction. If a little cholesterin is placed in a porcelain dish with
the addition of a few drops of a mixture of 2 or 3 vols, of concentrated hydrochloric
acid or sulphuric acid and 1 vol. of a rather dilute solution of ferric chloride, and
carefully evaporated to dryness over a small flame, a reddish-violet residue is.
first obtained and then a bluish-violet.
If a small quantity of cholesterin is evaporated to dryness with a drop of
concentrated nitric acid, one obtains a yellow spot which becomes deep orange-red
with ammonia or caustic soda (not a characteristic reaction). ’
Cholesterin combines with saponin (Windaus, Yagi) and when a solution
of cholesterin in boiling 95 per cent alcohol is treated with a warm 1 per cent
solution of digitonin in 90 per cent alcohol, a precipitate of digitonin-cholesteride
is obtained. If the amount of the washed and dried digitonin-cholesteride is
multiplied by 0.25 the quantity of cholesterin is obtained (Windaus 4
). The
cholesterin esters are not precipitated by digitonin.
Koprosterin is the name given by Bondzynski to the cholesterin which was
isolated by him from human feces, although it was prepared earlier by Flint
and designated as stercorin. It dissolves in cold, absolute alcohol and very readily
in ether, chloroform, and benzene. It crystallizes in fine needles which melt at
95-96° C. (89-90° according to Hausmann), and is dextrorotatory (of) D = +24°.
It gives the same color reactions as cholesterin, with the exception that it does
not give a reaction with propionic anhydride. According to Bondzynski and
Humnicki it is a dihydrocholesterin, with the formula C27H48O, which is formed
in the human intestine by the reduction of ordinary cholesterin. According to
Kusumoto as well as Dorbe and Gardner, koprosterin also occurs in the intes-
tine of dogs. The koprosterin prepared by H. Fischer from human feees seems
to be identical with that prepared by Bondzynski. It is remarkable that Boehm 6
1
Ber. d. d. chem. Gesellsch., 41.
2
Zeitschr. f. physiol. Chem., 50, 53, 58, and Ber. d. d. chem. Gesellsch., 41.
3
Zeitschr. f. physiol. Chem., 15.
* Windaus, Zeitschr. f. physiol. Chem., 65; Yagi, Arch. f. exp. Path. u. Pharm., 64.
6 Bondzynski, Ber. d. deutsch. chem. Gesellsch., 20; Bondzynski and Humnicki,
Zeitschr. f. physiol. Chem., 22; Flint, ibid., 23, and Amer. Journ. Med. Sciences,
1862; Muller, Zeitschr. f. physiol. Chem., 20; Hausmann, Hofmeister’s Beitrage, 6;
Kusumoto, Bioch. Zeitschr., 14; Dor6e and Gardner, Proc. Roy. Soc. London, 80,
Bet I’ : II. Fischer, Zeitschr. f. physiol. Chem., 73; Boehm, Bioch. Zeitschr., 33.
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