A text-book of physiological chemistry / Authorized translation from the author's enl. and rev. 3rd German ed., by John A. Mandel.

  • Olof Hammarsten
Date:
1898
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Licence: Public Domain Mark

Credit: A text-book of physiological chemistry / Authorized translation from the author's enl. and rev. 3rd 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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    decomposition (in tryptic digestion). On the extensive decomposi- tion a cliromogen may also be formed, which gives a violet color with chlorine- or bromine-water. This chromogen, which is formed in all far-reaching decompositions of proteids where lencin and tyrosin are formed, is called proteinoc]iro7nogen by STADELMAisrisr' and tryptophan by Neumeister. JSTencki ' considers this chromo- gen as the mother substance of various animal pigments. ISTEisrcKi * has found on the addition of bromine to the digestive fluid contain- ing proteinochromogen that at least two different bodies containing different quantities of bromine are produced. Both bodies show, although not obtained quite pure, a close relationship to certain animal pigments in regard to elementary composition. One stands close to haematoporphyrin, or bilirubin, and the other to the animal melanins. A great many substances are produced in the putrefaction of proteids. First the same bodies as are formed in the decomposition by means of proteolytic enzymes are produced, and then a further decomposition occurs with the formation of a large number of bodies belonging to both the alipathic and aromatic series. Belong- ing to the first series we have ammonium salts of volatile fatty acids, such as caproic, valerianic, and butyric acids, also carbon dioxide, methane, hydrogen, sulphuretted hydrogen, methyl- mercaptan,* and others. The ptomaines also belong to these products and are probably formed by very different chemical processes or even syntheses. E. Salkowski ' divides the putrefactive products of the aro- matic series into three groups: (a) the phenol group, to which tyrosin, the aromatic oxy-acids, phenol, and cresol belong; {h) the phenyl group, including phenylacetic acid and phenylpropionic acid; and lastly (c) the indol group, which includes indol, skatol, and skatolcarbonic acid. These various aromatic products are formed during the putrefaction with access of air. JSTencki and Bovet' obtained only p.-oxyphenylpropionic acid, phenylpropionic acid, and skatolacetic acid on the putrefaction of proteids by 1 Zeitschr. f. Biologie, Bd. 26. 2/WfZ., S. 339. ' Schweizerische Wochenschr. f. Pharmacie, 1891. * Ber. d. deutscli. cliem. Gesellsch., Bd. 28. 'See Nencki and Sieber : Monatshefte f. Chem., Bd. 10. «Zeitschr. f. pbysiol. Chem., Bd. 12, S. 215. 'Monatshefte f. Chem., Bd. 10.
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