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.

    19/28 (page 491)
    Pilocarpidine Ficrate came down as an oil on attempting to crys¬ tallise from hot water the precipitate obtained by adding picric acid to the aqueous solution of the nitrate, and all attempts to crystallise it failed. This behaviour is very different from that of the picrates of pilocarpine and isopilocarpine, which crystallise with ease. Specific Rotation of the Base. —An endeavour was made to determine this constant by a similar method to that employed for pilocarpine, but owing to the readiness with which pilocarpidine undergoes de¬ composition, a satisfactory result was not obtained. The nitrate was therefore dissolved in a little water, a molecular proportion of caustic soda added, the solution made up to a definite volume, and the rotation observed; then another molecular proportion of alkali was added, and the rotation again taken. The results were as follows : aD= +1*25°; 1= Idem.; c = l*5374; [a]D= +81*3°. with alkali: aD= +0*5°; l — l dcm.; c= 1*419; [a]D = +35*2°. Pilocarpidine thus behaves similarly to the other bases examined. Non-existence of Filocarpidine in Pilocarpine Nitrate of Commerce and in Jaborandi Leaves. The properties which differentiated pilocarpidine from the other bases were the great solubility of the nitrate in water or alcohol, and the formation of an amorphous picrate. The nitrate was re¬ peatedly fractionated from absolute alcohol and from mother liquors, and the product having the lowest melting point was carefully examined for pilocarpidine by forming the platinichloride and the picrate. From 28 grams of pilocarpine nitrate of commerce, a nitrate was obtained melting at 143°, and the mother liquors from this fraction gave a platinichloride melting at 218°, this being the melting point of pilocarpine platinichloride. The fraction melting at 143° crystallised in two fractions and gave melting points of 150° and 143° respectively. There was thus no evidence obtained of the existence of pilocarpidine in this sample of pilocarpine nitrate. From the alkaloid obtained by working up a large quantity of the leaves, 90 grams of a nitrate melting from 149—160° were obtained. This was converted into hydrochloride, recrystallised from absolute alcohol, and the alkaloid from the mother liquors converted into nitrate, which was treated as above described. The final fraction gave a nitrate melting at 143°, yielding an amorphous picrate, which afterwards, however, became mostly crystalline. The crystals proved to be chiefly pilocarpine picrate. The alkaloid was regenerated from the amorphous picrate and converted into the platinichloride, which