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CEPHALIN AND CUOBIN. 249
The cephalin from the brain has, according to Falk,1
a different composi-
tion than that of the nerves and certain observations indicate that there
are several cephalins.
Cephalin occurs quite abundantly in the brain and also in nerves
and in the egg-yolk. The statements as to its further occurrence in the
animal kingdom require substantiation.
Cephalin is amorphous, not very plastic, and more easily triturated
than lecithin. It is readily soluble in cold ether, in chloroform and
benzene but differs from lecithin by being insoluble or soluble with difficulty
in alcohol. As unsaturated phosphatide it gives, like lecithin, a positive
reaction with Pettenkofer’s bile-acid test. The cadmium- and plat-
inum chloride combinations are soluble in ether. Cephalin is obtained
from the brain, after dehydration with acetone, by extracting with ether
and precipitating the concentrated ethereal extract with alcohol. In
regard to the preparation and detection of cephalin we must refer to more
extensive hand-books.
The purest phosphatide prepared thus far seems to be cuorin, dis-
covered by Erlandsen.
Cuorin, C71H125NP2O21, is a monaminodiphosphatide prepared by
Erlandsen 2
from the heart muscle of the ox, and which has an iodine
equivalent of 101. It yields as cleavage products 3 molecules fatty acids
of unknown nature, partly or entirely belonging to the series CnH2n -402
and CnH2n-602; also glycerin, phosphoric acid and a base which is
not well known, but it is not choline. Cuorin is autooxidizable, and gives
Pettenkofer’s bile-acid test.
Cuorin is amorphous, yellowish-brown and similar to rosin. It
gives a neutral solution with water which is like an emulsion. Cuorin
does not reduce Fehling’s solution, even after boiling with acids. It is
soluble in ether, chloroform, petroleum ether and carbon disulphide.
It dissolves with difficulty in benzene ; it is insoluble in ethyl and methyl
alcohol and in acetone. Cuorin is precipitated from its alcohol-ether
solution by cadmium or platinum chloride.
1
Bioch. Zeitschr., 13 and 16.
2
Zeitschr. f. physiol. Chem., 51, where the method of preparation is described.
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