A text-book of physiological chemistry / By Olof Hammarsten; authorized translation from the author's enl. and rev. 4th German ed. by John A. Mandel.

Hammarsten, Olof, 1841-1932.

Date:: 1901 [©1900]

Credit: A text-book of physiological chemistry / By Olof Hammarsten; authorized translation from the author's enl. and rev. 4th German ed. by John A. Mandel. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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$mentioned above: the tyrosin (oxyphenylamidopropionic acid), the phenyl- amidopropionic acid, and the skatolamidoacetic acid. Maly,' on account of the oxyprotosnlphonic acid prepared hy him, considers it not necessary to recognize more than one aromatic group in the jjroteid molecule. By the oxidation of proteid by means of potassium permanganate, Maly obtained an acid, oxyprotosnlplionic acid, C 51.^1; H 0.89; N 14..50; S 1.77; 0 ^5.54, which is not a cleavage product but an oxidation product in which the group HII is changed into SO,.Oil. This acid does not give the proper color reaction with Millox's reagent caused by aromatic hydroxyl derivatives (see below), nor does it yield the ordinary aromatic splitting products of the proteids. Still the aromatic group is not absent, but it seems to be in another binding from that in ordinary proteid. On oxidizing with potassium dichromate and acid this group a2)pears as benzoic acid, and on fusing with alkali benzol is given off. On continuous oxidation a new amorphous acid, peroxyproteic acid— C 4G.:i2; H (i.4;3; N l->.:30; S 0.90; 0 34.09,1^—is produced from the oxy- protosnlphonic acid. The peroxyproteic acid gives the Buiret reaction, but is not precipitated by most of the reagents precipitating proteids. According to Berxer'^ in the formation of oxyprotosulphonic acid not only does an oxidation take place, but also at tiie same time a deep cleavage due to the presence of alkali. He was able to show the presence of albu- moses and peptones as side products. These differed from the correspond- ing products produced in digestion by not yielding any indol or skatol on fusing with potash, by not giving ]\riLLOX's reaction, and not containing sulphur blackening lead. lie also found acetic acid, propionic acid, and butyric acid, and the presence of valerianic acid and basic bodies (lysin, histidiu) was shown among the cleavage products. On the cleavage of peroxyproteic acid with baryta he found the cleavage products previously obtained by Maly (with the exception of amidovalerianic acid and isogly- cerinic acid), besides also acetic, propionic, butyric acids, benzaldehyde and pyridin. As in oxidation with potassium permanganate, so also may the proteids be changed by the action of the halogens, namely, so that they contain no sulphur which can be split off by alkali, or give Millox's reaction, nor yield tyrosin as a cleavage product. By the action of chlorine, bromine, and iodine on proteids the halogens pass into more or less firm union with the proteid (Loew, Blum, Blum and Vaubel, Liebreciit, Hop- kins and Brook, Hofmeister), and it is possible to prepare derivatives ' Sitzuiigsber. d. k. Akad. d. Wisseusch. Wieu, Abth. II, 1885, and Abth. II, 1888. Also MoniUshefte f. Cliem., Bdd. 6 and 9. See also Boudzynski and Zoja, Zeitacbr. f. pbysiol. Cheiu.. Bd. 19. * Zeilschr. f. physiol. Cbem., Bd. 26,$