Full resolution (JPEG) - On this page / på denna sida - XI. Brain and Nerves - Cerebrosides
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
CEREBRON. 611
Whether the above-described cerebrosides are chemical individuals or
mixtures, i. e., impure substances, is still undecided. The purest cere-
broside thus far investigated is undoubtedly Thierfelder’s cerebron,
and there is hardly any doubt that the above-mentioned cerebrosides
consist essentially of this body.
Cerebron. This cerebrin, isolated by Thierfelder and Worner
and then especially studied by Thierfelder, was first isolated by Gam-
gee and called pseudocerebrin by him. Thudichum’s phrenosin is,
according to Gies, 1
identical with cerebron. Cerebron can be prepared
directly from the brain without saponification with baryta, by treat-
ment with alcohol containing benzene or chloroform at a temperature
of 50°, and hence it is considered as existing preformed in the brain.
According to Thierfelder, cerebron has the formula C48H93XO9; it
melts at 212°, dissolves in warm alcohol, and separates out on cooling.
From proper solvents (acetone or methyl alcohol containing chloroform)
it may be separated as small needles or plates. If cerebron is suspended
in 85-per cent alcohol at a temperature of 50° C. it balls together in
amorphous masses, and from these needle- and leaf-shaped crystals
gradually form. It is dextrorotatory, and in about a 5-per cent solu-
tion in methyl alcohol (containing 75 per cent chloroform) is (o0d = +7.6
o
(Kitagawa and Thierfelder). According to Thierfelder it yields
as cleavage products, galactose, cerebronic acid (Thudichum " neuro-
stearic acid ") and sphingosin which is in part obtained as such and part
as dimethylsphingosin. The base sphingosin, C17H35XO2, discovered
by Thudichum, is, according to Thierfelder and to Levene and Jacobs,2
an unsaturated, diatomic, monoamino-alcohol which is readily soluble
in alcohol, ether, acetone and petroleum ether but insoluble in water,
nas an alkaline reaction and has not been obtained in a crystalline
state. The sulphate of dimethylsphingosin crystallizes, on the contrary,
from alcohol. Cerebronic acid is an oxyacid with the formula C25H50O3,
which is crystalline and which gives a crystalline methyl ester which
melts at 65° C. It has been obtained by Levene and Jacobs 3
in part
in a dextrorotatory and in part as an inactive form. The first melts
at 106-108° and the other at 82-85° C.
Cerebron can best be prepared, according to Thierfelder and
Kitagawa, by decomposing the protagon in methyl alcohol containing
1
Thierfelder and Worner, Zeitschr. f. physiol. Chem., 30; Thierfelder, ibid., 43,
44, 4G, with Kitagawa, ibid., 49; with H. Loening, ibid., 68, 74, 77; Gamgee, Text-
book of Physiol. Chem., London, 1880; Thudichum, 1. c; Gies, Journ. of Biol.
Chem., 1 and 2.
2
Thierfelder and O. Riesser and K. Thomas, Zeitschr. f. physiol. Chem., 77;
Levene and Jacobs, Journ. of biol. Chem. 11.
5
Journ. of biol. Chem., 12.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
