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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    decolorise aqueous acid permanganate, but decolorises bromine in chloroform solution. Its chemical properties are thus very similar to those of pilocarpine and fsopilocarpine; its solubilities, and physiological properties are also similar, and its parent compound, pilosine, occurs in the same plant which produces these glyoxaline derivatives. It is therefore highly probable that pilosinine itself is not only a glyoxaline derivative, but a lower homologue of pilocarpine and isopilocarpine, having the constitutional formula given below: CH9-Ca-CH9-C*NMe\nxj i 2 i 2 11 ^OII CO CH2 CH--N \/ o Pilosinine. C2H5*CH“CH*CHC)*C*NMe CO CEL C H-N >CH 0 Pilocarpine. Pilosinine is here represented as a 1:5-glyoxaline derivative owing to its connexion with pilocarpine and isopilocarpine; there is, however, no direct evidence that it is a 1:5- rather than a 1:4-gly- oxaline derivative. The above formula satisfactorily accounts for all the known properties of pilosinine, and explains the similarity of its behaviour with that of pilocarpine and isopilocarpine. It also permits of the construction of a probable formula for pilosine. Since pilosine is decomposed into benzaldehyde and pilosinine on boiling with strong aqueous sodium hydroxide, and yields anhydro- pilosine when dehydrated by means of acetic anhydride, it must contain the grouping C6H5*CH(OII) attached to a carbon atom, which also bears a hydrogen atom. This grouping must, therefore, displace a hydrogen atom in one of the three methylene groups of the pilosinine molecule in such a way as to give rise to a formula for pilosine capable of explaining the ready decomposition of this alkaloid into pilosinine and benzaldehyde. This condition is fulfilled only in the case where pilosine is represented as derived from pilosinine by the displacement by C6H5*CH(OH) of one of the hydrogen atoms of the methylene group in the a-position with reference to the carboxylic group: C6H5-CH(OH)-CH--CH-CH2*C-NMe^CH CO CH2 ~ Cfl-JST \/ o Pilosine. for, if the C6H5*CH(OH) group substituted either of the other two methylene groups, it would give rise to compounds which would not be expected to decompose into benzaldehyde and pilosinine. The formula for pilosine given above, however, represents pilosine
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