Preparation and properties of some new tropeines / by H.A.D. Jowett and A.C.O. Hann.

  • Jowett, H. A. D. (Hooper Albert Dickinson)
Date:
[1906]
Catalogue details

Licence: In copyright

Credit: Preparation and properties of some new tropeines / by H.A.D. Jowett and A.C.O. Hann. Source: Wellcome Collection.

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    what extent Ladenburg’s generalisation applies. As the result of an investigation of the physiological action of a number of tropeines, this chemist has stated that the characteristic action of a tropeine, namely, its mydriatic action, depends not only on the presence of a tropine complex, but on the nature of the acyl group attached to it, which must contain (1) a benzene residue, (2) an aliphatic hydroxyl in the side- chain containing the carboxyl group. Thus, acetyl-, benzoyl-, and salicyl-tropeines do not produce mydriasis, but mandelyltropeine does. To test this generalisation further, we prepared glycolly 1- and pro- tocatechyl-tropeines in addition to those already mentioned. The pre¬ sent paper contains an account of the preparation and properties of these substances, as well as those of their principal suits. The physiological experiments conducted by Professor C. It. Marshall will be described in detail elsewhere, but a brief account of his results may now be given. First, as regards the difference in action between a lactone and its corresponding hydroxy-acid, it has been found that both terebyl- and phthalidecarboxyl-tropeines, which produce an atropine-like effect on the heart, lose this action after a molecular proportion of alkali has been added to the base. They thus show, in aqueous and alkaline solution, a difference in action analogous to that observed in the case of pilocarpine. As regards Ladenburg’s generalisation that, to obtain a tropeine possessing mydriatic action, it is necessary to have the tropine complex attached to an acyl group containing an aromatic nucleus, it is found that this does not apply in the case of terebyltropeine. Whilst glycollyltropeine may be said to be inactive physiologically, terebyl- tropeine has a distinct mydriatic action, though very much weaker than atropine or homatropine. Of the five tropeines examined, all were found, when tested on the vagus endings in the heart, to have an action similar in kind to that of atropine but—especially in the case of glycollyltropeine—very much weaker. The order of activity was as follows : (1) Phthalidecarboxyltropeine, (4) Methylparaconyltropeine, (2) Terebyltropeine, (5) Glycollyltropeine, (3) Protocatechyltropeine, the last on the list being very feebly active and much weaker than the rest. When applied to the eye in 1 per cent, solution (as a salt), the phthalidecarboxyl- and terebyl-tropeines both produced marked dilatation of the pupil, but both were very much weaker than either atropine or homatropine. The other three tropeines had no distinct mydriatic action. The general results of this inquiry have proved, therefore :