Some colour reactions of adrenine and allied bases / by A.J. Ewins.

  • Ewins, Arthur James.
Date:
[1910?]
Catalogue details

Licence: Public Domain Mark

Credit: Some colour reactions of adrenine and allied bases / by A.J. Ewins. Source: Wellcome Collection.

    10/16 (page 322)
    ordinary temperature the solutions gradually become yellow in colour and the reaction with starch is readily obtained. On heating, the bases of the dihydroxyphenylethylamine series give the normal colour reaction while aminoaceto-catechol and the other bases of this type give yellow coloured solutions. Further a number of catechol derivatives examined with regard to this reaction gave a similar result. Thus the following catechol derivatives Catechol Protocatechuic aldehyde Protocatechuic acid Nitroprotocatechuic acid Dihydroxymandelic ethyl ester (OH)2C6H4 (OH)2C6H3CHO (OH)2C6H3COOH (0H)2C6H2N02.C00H (OH)2C6H3. CHOH. COOC2H5 all yield free iodine with this reaction while methylene-dioxy compounds, e.g. Piperonylic acid CH202C6H3C00H Methylene dioxymandelic ester CH202C6H3CH0HC00C2H5 as well as Dimethoxyphenylethylamine (CH30)2C6H2CH2CH2NH3, give no reaction at all. It would appear therefore that free iodine must play an important part in this reaction, which is however to some extent modified by the conditions obtaining, since the coloration produced is distinctly different from that obtained by the direct action of free iodine on solutions of the bases. The reaction is again very delicate with pure solutions of the bases. According to my experiments, a distinct reaction may be obtained with a solution of one part of adrenine in one million (1—1,000,000). The same order of sensitiveness is shown by the other reactive bases. This reaction has been modified and intensified by G. Bayer1 who finds that by addition of sulphanilic acid to the solution as prepared for the Frankel-Allers’ reaction there is produced on heating a yellow colour instead of the normal rose tint. The reaction was distinctly given with a solution of one part of adrenine in five millions. I have confirmed this result and have found the same reaction to hold good for the remaining reactive bases. According to Bayer naphthionic acid acts in a similar manner, intensifying the reaction and producing not a yellow but a distinct 1 Biochem. Ztschr. xx. 176. 1909.