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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    both base and salts with acids, whilst anhydropilosine is dextro¬ rotatory as base, but Igevorotatory as salt; all three alkaloids are lasvorotatory in the form of the alkali salts of the corresponding hydroxy-acid. The specific rotation of the three alkaloids as base, salt with acid, and salt with alkali calculated in each case for base is given below, together with the corresponding values for pilocarpine, isopilo¬ carpine, and pilocarpidine, calculated from Jowett’s determinations. Specific Rotation of Base as: Base. Salt with acid. Salt with alkali. Pilocarpine. +100-5° +108-0° +31 -5° is-oPiloearpine. +42*8 +46 5 +00 Pilocarpidine. +81 3 + 970 +35 2 Pilosine . +39’9 +24‘6 -67 6 Anhydropilosine ... +66'2 -20 8 — 132*7 Pilosinine . +14 2 +5’8 -5*8 Jowett has shown that the difference between pilocarpine and isopilocarpine is due to the change of sign of one of the two optically active carbon atoms, pilocarpine readily yielding isopilo¬ carpine on treatment with alkali. Now pilosine can be recovered mainly unchanged after boiling for some time with dilute aqueous sodium hydroxide, and it is therefore clear that pilosine and its derivatives correspond in stereochemical relations rather with isopilocarpine than with pilocarpine. Physiological Action of Pilosine and its Derivatives. Dr. P. P. Laidlaw, of the Wellcome Physiological Research Laboratories, kindly tested the physiological action of these alkaloids with the following results: Pilosine has a very weak pilocarpine action, since it produces a typical but very weak inhibition of the cat’s heart when given in 20 milligram doses. Anhydropilosine shows a similar behaviour. Pilosinine has a mild pilocarpine action. It inhibits the heart of frogs and cats, and causes a fair reaction of saliva. It is somewhat stronger in this respect than pilosine, but it is still very much weaker than pilocarpine. Experimental. Isolation of Pilosine from Pilocarpus microphyllus. The residual syrup from several tons of Pilocarpus microphyllus leaves from which the pilocarpine and ?sopilocarpine had been removed as completely as possible during manufacture, was diluted with water, and fractionally precipitated with ammonia. This