The constituents of commercial chrysarobin / by Frank Tutin and Hubert W.B. Clewer.

  • Tutin, Frank.
Date:
1912
Catalogue details

Licence: In copyright

Credit: The constituents of commercial chrysarobin / by Frank Tutin and Hubert W.B. Clewer. 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.

    19/22 page 304
    mixtures of chrysophanolanthranol and emodinanthranol, and chrysophanolanthranol and the monomethyl ether of dehydro- emodinanthranol respectively. The substance, C17H1404, obtained bv Jowett- and Potter (loc. cit.) could not be isolated from any of the products examined by the present authors. In view of the variable nature of chrysarobin it is obviously fallacious to demand that it should fulfil exact requirements regarding its solubility, esc., as is done by some national pharma- copoeias, notably that of the United States; moreover, the tests given by the last-mentioned work for distinguishing commercial chrysarobin from “ chrysophanic acid ” are of no value, for “ chrysophanic acid ” does not yield the reactions there attributed to it, and, furthermore, it is invariably a constituent of chrysarobin. The general characters of commercial chrysarobin, such as are described by the British Pharmacopoeia, should be sufficient for the control of the purity of the product. There is no definite knowledge as to which constituent or con- stituents of commercial chrysarobin its medicinal value is to be attributed. The active constituent has generally been presumed to be chrysophanolanthranol, but there appears to be a lack of evidence to support this view, especially as the artificially prepared anthranol has been stated not to exhibit the action of the natural drug. The valuable constituent may therefore be one of the new compounds described in the present communication. The physiological action of chrysarobin is known to be very variable (compare Pharm. J., 1911, [iv], 87, 630), and this is doubtless attributable to the differences in the composition of the drug, such as are shown in the present communication to occur. It is not easy to see, however, how a more uniform product could be obtained from the chrysarobin at present found in commerce, since it is a difficult and most tedious process to ascertain even the approximate composition of a sample of the product in question. It would nevertheless appear significant that the differences observed between the three samples examined by the present authors are, to a great extent, such as would be caused by the employment of different methods for the extraction of the original Araroba powder, or, more particularly, by the varying degrees of complete- ness with which the extraction had been conducted. It is probable, therefore, that commercial chrysarobin would be of much more uniform composition if a definite solvent could be adopted for the extraction of the Araroba powder, and the extraction always made complete. The Wellcome Chemical Research Laboratories, London, E.C.
    digitised image 1
    digitised image 2
    digitised image 3