Experiments on antimony compounds used in the treatment of Bilharzia disease and kala-azar / by W.H. Gray and J.W. Trevan.

  • Gray, William Herbert.
Date:
[1931]
Catalogue details

Licence: Public Domain Mark

Credit: Experiments on antimony compounds used in the treatment of Bilharzia disease and kala-azar / by W.H. Gray and J.W. Trevan. Source: Wellcome Collection.

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    Known as “ stibosan,” was more successful. Two derivatives of stibanilic acid of pronouncedly low toxicity remain to be mentioned, “ neostam ” (stibamine glucoside), in which a glucosyl group takes the place of the acetyl group present in stibacetin, and “ neostibosan,” which is stated to be a diethylamine salt of stibanilic acid. With these two substances the infection can be cured in a few days, and they are thus within measurable distance of achievement of the “ therapia sterilisans magna ” visualised by Ehrlich, but unfulfilled, as yet, by any other artificially prepared chemotherapeutic remedy. “ Urea stibamine ” was stated by Braiimachari (1924) to be the ammonium salt of the carbamyl derivative of stibanilic acid, (V), NH.CO-NH H—N-CO-N—H it c I w H—C C—H H—C C—H \ // C (NH4)0—Sb—OH o V. c / ^ H—C C—H H—C C—H \ // C HO—Sb—OH O VI. c / \\ H—C C—H II I H—C C—H i a c HO—Sb—OH II O but chemical examination of the commercial material showed that it was a mixture which could at most contain only an inconsiderable amount of this substance, the principal constituents being a substance corresponding in composition to the di-substituted urea, sj/w-diphenylcarbamide-4 : 4’-distibinic acid (VI), and antimonic acid, the latter being trypanocidally inactive. Con¬ firmation was obtained in two ways : the di-substituted urea was prepared in a pure state, by means of carbonyl chloride, and found to have a high trypanocidal activity corresponding to that of “ urea stibamine,” and the monosubstituted urea, (V), in a pure state, to be less active than “ urea stibamine,”* also, the action of urea upon stibanilic acid was studied under various conditions ; when these were chosen theoretically to favour the forma¬ tion of the di-substituted urea, analysis of the resulting product and its relatively high trypanocidal activity confirmed the presence of this substance. Less than 5 per cent, of urea was found, so that the statement of Ghosh and others (1928) that “ urea stibamine ” is a complex salt of urea, from which this constituent may readily be removed by washing, is not borne out. * Schmidt (1930) has also prepared ammonium />-carbamidophenylstibinate by another method, and reports that it is inactive in hamster kala-azar.