The action of the cinchona and certain other alkaloids in bird malaria / by J.A. Goodson, T.A. Henry, and J.W.S. MacFie.

  • Goodson, John Augustus.
Date:
[1930]
Catalogue details

Licence: Public Domain Mark

Credit: The action of the cinchona and certain other alkaloids in bird malaria / by J.A. Goodson, T.A. Henry, and J.W.S. MacFie. Source: Wellcome Collection.

    19/24 (page 887)
    Quitenine series (Table II). It has been clearly established already that the free acid itself—quitenine— is inactive both in bird malaria and in human malaria [Stephens etaL, 1919], and the object of examining the series of esters of quitenine and the analogous derivatives of the other three cinchona alkaloids dealt with in Table II was to confirm the observation of Giemsa, Weise and Tropp [1926] that the ethyl ester of quitenine is active, and to ascertain whether, by the use of higher alcohols, more active alkylquitenines could be obtained. The results recorded in Table II make it clear that quitenine does regain activity on esterification and that, on the whole, activity increases as the homologous series is ascended, reaching its maximum at butyl or amyl, at which point cures begin to appear. But, apart from these occasional cures, none of these esters appears to approach hydroquinine or even quinine and quinidine in activity, and the simple quitenine esters do not appear to hold out any hope of a considerable improvement on quinine. It has been pointed out already by Schnitzer [1926] that esters of quitenine act as local anaesthetics. 13r J. Trevan has kindly tested this point for us. He finds that the esters do act as local anaesthetics, the benzyl ester being markedly active, but that they are too irritating to be of practical value. We have also examined the esters of the carboxylic acids analogous to quitenine derived from the other three cinchona alkaloids, viz. cinchotenidine from cinchonidine, quitenidine from quinidine and cinchotenine from cin¬ chonine. In these three cases only the ethyl and isoamyl esters were used. Here also it is clear, though at most two birds only were used in the trial of each substance, that the esters are active, the best of them being isoamyl- cinchotenidine. 0 T11ER DRUGS WITH A REPUTATION FOR ANTIMALARIAL ACTION. Alstonia species. Two of the authors have at present under chemical ex¬ amination the following species of Alstonia: A. congensis A. scholaris A. macrophylla A. constricta West Africa. India and Philippine Islands. Philippine Islands. Australia. The first two contain the alkaloid echitamine [Goodson and Henry, 1925]. The third and fourth contain no echitamine, but are rich in alkaloids, which are still under examination. The total alkaloids of A. scholaris showed perhaps a slight action in doses of 2*5 mg., which was the highest dose tolerated, and those of A. constricta in doses of 10 mg., but not in doses of 5 mg. Echitamine sulphate was slightly active at a dosage of 5 mg. The total alkaloids of A. macrophylla and A. congensis were inactive.