The proposed method of microsublimation for the detection of aesculin and the identification of gelsemium / by Frank Tutin.

  • Tutin, Frank.
Date:
[1912]
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Licence: In copyright

Credit: The proposed method of microsublimation for the detection of aesculin and the identification of gelsemium / by Frank Tutin. 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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    is of such value that it should be adopted by the Pharma- copoeias as a test for the identity of gelsemium In view of certain facts, however, it appeared to the present author that the subject required further investiga- tion. In the first place, the suggestion that the chemical and physical properties of a compound can be greatly altered by the conditions under which it is examined cannot be entertained. A small amount of a compound will melt at the same temperature when heated between two microscope slides as when heated in a capillary tube in the ordinary manner, and it will not become more volatile by being examined under a microscope. In the second place, gel semium does not contain any aesculin, and therefore Tun- mann cannot have obtained a sublimate of this compound from the drug in question. Tim fluorescent principle in gelseminm has been shown to be scopoletin (aesculetin 5-methyl ether), and not aasculin.2 3 Sonnenschein,3 whose work is referred to by Tunmann, stated that he isolated sesculin from gelsemium, but a consideration of the method employed by him renders it evident that the compound he obtained could not have been the glu coside in question, and must have consisted of scopoletin. Thus Sonnenschein states that the drug was extracted with a mixture of equal parts of alcohol and water, the extract concentrated, and deprived of resin. The liquid was then treated with basic lead acetate, the pre- cipitate collected, suspended in water, and decomposed by means of hydrogen sulphide, the crystalline compound being obtained by extracting the resulting liquid with ether. He also states that a further amount of “ resculin ” was ob- tained from the filtrate from the basic lead acetate precipi- tate by extraction with ether, after the removal of the lead by means of hydrogen sulphide. Not a trace of sesculin, however, can be removed from its aqueous solution by extraction with ether, whilst scopoletin, on the other hand, may readily be removed by this means. Furthermore, it is stated by Sonnenschein that the “ sesculin ” obtained by him from gelsemium is identical with the “ gelseminic acid” of Wormley,4 but the latter compound has been shown by Schmidt5 to be scopoletin. 2 Moore, Journ. Chem. Soc., 1910, 97, 2223; 1911, 99, 1043. 3 Ber., 1876, 9, 1182, 4 Amer. Journ. Pliarm1870, 42, 1. 5 Arch. Pharm.t 1898, 236, 236.