4-L-aminoethylglyoxaline (L-iminazolylethylamine) and other active principles of ergot / by George Barger and Henry Hallett Dale.

  • Barger, George, 1878-1939.
Date:
[between 1910 and 1919?]
Catalogue details

Licence: In copyright

Credit: 4-L-aminoethylglyoxaline (L-iminazolylethylamine) and other active principles of ergot / by George Barger and Henry Hallett Dale. Source: Wellcome Collection.

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    CCLXV.—4-p-Aminoethylglyoxaline (fi-Iminazolylethyl- amine) and the other Active Principles of ErgotA By George Barger and Henry Hallett Dale. For many years ergot has been notorious among drugs on account of the ignorance and division of opinion concerning the nature of its active principles. The problem had, indeed, approached solution in 1875, with Tanret’s discovery of ergotinine and Buchheim’s suggestion that ergot owes its activity to decomposition products of proteins produced by putrefaction. This discovery and suggestion were largely obscured by the work of subsequent investigators, which resulted rather in the physiological characterisation of impure products (sphacelinic acid, sphacelotoxin, etc.) than in chemical isolation of active principles. Of late years, however, a considerable measure of agreement has been reached. The alkaloid ergotoxine (Barger and Carr) was also found by Kraft, who named it hydroergotinine, and the formulas assigned to ergotinine and ergotoxine (Trans., 1907, 91, 337) have been confirmed by Tanret and by Kraft respectively. There is also a consensus of opinion regarding the effect of ergotoxine on the blood-vessels and uterus, and its activity in producing gangrene. Thus ergot, in common with many drugs, contains a complex physiologically active alkaloid. In addition, however, there are present in ergot a number of simpler bases, derived from amino- acids by the elimination of carbon dioxide. Such bases are generally formed in putrefaction. Ergot, as a fungus, is more closely related to bacteria than to the higher plants, from which all other important vegetable drugs are derived. Thus the peculiar nature of these active principles of ergot is due to its peculiar systematic position in the vegetable kingdom. Putrefaction bases were first isolated from ergot by Rielander (.Sitzungsber. Ges. Naturw. Marburg, August 5th, 1908), who found putrescine and cadaverine, which only have a feeble physiological action. The first markedly active base of this class, ^-hydroxy- phenylethylamine, was isolated from ergot by ourselves (Barger and Dale, Proc. Physiol. Soc., May 15th, 1909, in J. Physiol., 1909, 38, lxxvii; Barger, Trans., 1909, 95, 1123). It is formed from tyrosine during putrefaction, but appears to be present also in fresh ergot. It is the chief pressor constituent of most aqueous ergot extracts, but does not produce contraction of the isolated uterus of the non-pregnant cat. In addition, we showed that iso- * A preliminary note on this subject was read at the meeting of May 26th, 1910.