Pilosine : a new alkaloid from Pilocarpus microphyllus / by Frank Lee Pyman.

  • Pyman, Frank Lee.
Date:
[between 1910 and 1919?]
Catalogue details

Licence: In copyright

Credit: Pilosine : a new alkaloid from Pilocarpus microphyllus / by Frank Lee Pyman. Source: Wellcome Collection.

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    CCXXXVII.—Pilosine: A New Alkaloid from Pilo¬ carpus microphyllus. By Frank Lee Pyman. Pilocarpine, CijHjgOgNg, its stereoisomeride isopilocarpine, and pilocarpidine, CioIii402N2> are the only alkaloids from the different varieties of jaborandi leaves which have been thoroughly charac¬ terised. Pilocarpine and isopilocarpine are found in most varieties. Pilo¬ carpidine is obtained from Pilocarpus jaborandi, but according to Jowett (Trans., 1900, 77, 473) does not occur in P. microphyllus. Now, Herzig and Meyer (Monatsh., 1898, 19, 56) have shown that pilocarpidine does not contain an A-methyl group, and it is probable that this alkaloid is the parent base of pilocarpine containing an imino-group in the place of the A-methyl group. In accordance with this view it has been found that pilocarpidine, in common with other glyoxalines containing a free imino-group, gives a deep red colora¬ tion with sodium diazobenzene-^?-sulphonate (Pauly’s histidine reagent). It was then found that the mother liquors from Pilo¬ carpus microphyllus containing the alkaloids remaining after the separation of pilocarpine and ^sopilocarpine also gave a well-marked red coloration with sodium diazobenzene-p^sulphonate. A large quantity of such residues (representing many tons of leaves) being available it was thought of interest to subject them to a fresh investigation following the movements of the base containing the free imino-group with the help of this colour reaction. After a lengthy and tedious process of separation, depending largely on the different solubilities of the bases in water, the residues gave (1) resinous matter, (2) a sparingly soluble oil giving an intense Pauly reaction, (3) a sparingly soluble crystalline base, which has been designated pilosine—this base, which was obtained in a yield amounting to 0'007 per cent, of the leaves, did not give the Pauly reaction; (4) a mixture of pilocarpine and wopilocarpine; and (5) the mother liquor from (4), which contained the remaining readily soluble bases, and gave only a moderate Paulv reaction.