The constitution of chrysophanic acid and of emodin / by H.A.D. Jowett and C.E. Potter.

  • Jowett, Hooper Albert Dickinson, 1870-1936.
Date:
[1903]
Catalogue details

Licence: In copyright

Credit: The constitution of chrysophanic acid and of emodin / by H.A.D. Jowett and C.E. Potter. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    CXXVII.—The Constitution of Chrysophanic Acid and of Emodin. By Hooper Albert Dickinson Jowett and Charles Etty Potter. Although chrysophanic acid and emodin have long been known to be respectively the di- and tri-hydroxy-derivatives of a methylanthra- quinone, the position of the substituting groups has remained un- determined. The exact constitution of these substances is, however, of considerable importance from a pharmacological standpoint, inas- much as they occur naturally in several drugs possessing a cathartic action. Hesse (Annalen, 1899, 309, 32) has suggested certain formulae for these substances, but he adduces no evidence, either theoretical or experimental, in support of his assumptions. The object of this investigation was to determine the position of the substituting groups, and, if possible, to synthesise the substances themselves. Although we have failed to accomplish these syntheses we are able, with a considerable degree of certainty, to propose formulae for both these compounds. Chrysophanic acid yields, on distillation with zinc dust, a product which Liebermann [Annalen, 1876, 183, 159) considered to be 2-methyl- anthracene, but owing to the great similarity which exists between the isomeric methylanthracenes this point cannot be considered as being definitely proved. Chrysophanic acid was not methylated, even when treated with excess of sodium and methyl iodide in methyl alcohol at 100° (Jowett and Potter, Trans., 1902, 81, 1584). It