Pilocarpine and the alkaloids of jaborandi leaves / by Hooper Albert Dickinson Jowett.

  • Jowett, H. A. D. (Hooper Albert Dickinson)
Date:
[1900?]
Catalogue details

Licence: In copyright

Credit: Pilocarpine and the alkaloids of jaborandi leaves / by Hooper Albert Dickinson Jowett. Source: Wellcome Collection.

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    alkaloid was present in jaborandi leaves, and named it jaborine, its formula being given as CnH1602N2. This base was amorphous and formed amorphous salts. These chemists also stated that pilocarpine on dry distillation with soda-lime yields trimethylamine. Methods of preparation of pilocarpine and a determination of its specific rotatory power were described by Petit (Ber., 1877, 10, 896) and by Poehl (,Jahresb., 1880, 993, 1074). Chastaing (Compt. rend., 1883, 97, 1435; 1885, 100, 1593) published a series of papers dealing with the chlorination and bromination of pilocarpine and its reaction with alkyl iodides. In 1885, Harnack and Meyer (iGhem. Centr., 1885, 628) described a third alkaloid in jaborandi leaves, which they named pilo- carpidine and ascribed to it the formula C^H-yC^Ng. This base, although amorphous, gave a crystalline nitrate, melting at 129 2 , and no precipitate with auric chloride. Between 1885 and 1887, Hardy and Calmels (Compt. rend., 102, 1116, 1251, 1562 ; 103, 277; 105, 68) published a series of papers dealing with the description of various salts of pilocarpine and pilo- carpidine, details of the conversion of the former into the latter, and experiments on the constitution of the alkaloid. They represented the base as a derivative of /3-pyridinelactic acid and trimethylamine, C5NH4-C(CH3)<^^y>0, and claimed to have completed the proof of the constitution by a partial synthesis of the alkaloid. The account of their work, however, is very unsatisfactory and incom- ete, and no reliance can be placed on their results : no description or analysis of the various crystalline salts is given and no proof is furnished of the identity of the product said to result from the decom¬ position of the alkaloid. Nothing further was published till 1896, when Merck (Merck’s Ber., 1896, 11), and shortly afterwards Kundsen (Ber. Pharm., 1896, 6, 164) reported their failure to confirm Hardy and Calmels’ results. In this year also, Paul and Cownley (Pharm. J., 1896, [iv], 3, 1, 437) drew attention to the unsatisfactory state of our knowledge of the subject, and noted the results of a few experiments on this group of alkaloids. The first complete account of pilocarpine and its salts, as also of pilocarpidine, was given by Petit and Polonowsky (J. Pharm., 1897, [vi], 5, 370,430,475; 6,8). In addition to the physical constants and analyses of the salts, important observations were recorded as to the optical behaviour of the bases under varying conditions. These chemists were able to convert pilocarpine into pilocarpidine by heat or by the influence of alkali, proved that the latter was isomeric with the former, and asserted, although on very slender experimental evidence, that the pilocarpidine so prepared was identical with that found in the leaves. They also pointed out several inaccuracies in Hardy and