The ureides of p-aminophenylstibinic acid / by W.H. Gray [and others].

Date:
[1931.]
Catalogue details

Licence: Public Domain Mark

Credit: The ureides of p-aminophenylstibinic acid / by W.H. Gray [and others]. Source: Wellcome Collection.

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    distibinic acid. Verification of this was afforded by preparation of these two ureides by separate and simpler methods and comparison of their physiological properties with those of “ urea stibamine (Brahmachari).” 3. The latter substance is prepared by heating stibanilic acid with urea solution, this acid being obtained by the customary alkaline hydrolysis of its acetyl-derivative. It is now found that the published directions for the latter process are insufficiently definite in one important particular, viz., the method of determining when hydrolysis is complete. Products containing varying amounts of unchanged p-acetylaminophenylstibinic acid may be obtained according to the conditions chosen for this test, still keeping within the scope of these published directions. When such a product is treated, under suitable conditions, with urea, the stibanilic acid present reacts in two ways :— (а) With formation of the ureide. (б) Undergoing hydrolytic fission with formation of antimonic acid. The former, in a pure state, does not form appreciably soluble salts ; its solubility in presence of the antimonic and acetylaminophenylstibinic acids is to be attributed to the action of these substances as protective colloids (see § 9). The relative amounts of the three substances in the final product, as well as of urea, which is difficult to remove from these amorphous materials, depend on the experimental conditions. This source of variation accounts for the difficulty in repeating the preparation of “ urea stibamine ” which has been reported bv other investigators (Napier, 1923 ; Uhlenhuth, Kuhn and Schmidt, 1925), and possibly for the alleged variation in the com¬ position of the samples on the Indian market (Ghosh and others, 1928 ; Napier, 1929). 4. It will be seen from the foregoing that this problem has been investigated biologically as well as chemically, and the opportunity has been taken to include in the physiological section, on a basis of the results obtained, a general dis¬ cussion of methods appropriate for the examination of all such chemothera¬ peutic problems from the physiological standpoint. 5. There is no evidence that the relative values of these products, as estimated by these experiments on mice, are transferable to their use in human kala- azar. For example, we find that stibamine glucoside is less active on trypano¬ somiasis in the mouse than urea stibamine,” whereas Napier (1929) finds that the two drugs are equal in therapeutic efficacy for kala-azar.