The constituents of Gloriosa superba / by Hubert William Bentley Clewer, Stanley Jospeh Green and Frak Tutin.

  • Clewer, Hubert W. B.
Date:
1915.]
Catalogue details

Licence: Public Domain Mark

Credit: The constituents of Gloriosa superba / by Hubert William Bentley Clewer, Stanley Jospeh Green and Frak Tutin. Source: Wellcome Collection.

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    described (T., 1914, 105, 1835), when it was ultimately separated into a fatty alcohol, melting at 77°, and a hydrocarbon, melting at 63—65°; both of these products, however, were insufficient for analysis. Isolation of Stigmasterol.—The alcoholic mother liquors from the crude mixture of fatty alcohol and hydrocarbon were concen¬ trated, and some ethyl acetate and a little water added. A con¬ siderable quantity of long, colourless plates then separated, which gave the colour reaction characteristic of the phytosterols. The entire product was heated with acetic anhydride, and the resulting acetyl derivative crystallised from alcohol until it melted con¬ stantly at 133°: 0T007 gave 0-3003 C02 and 0T020 H20. C-8T3; H = 113. 0'2095, made up to 20 c.c. with chloroform, gave aD — T23° in a 2-dcm. tube, whence [a]D — 58'7°. These results indicated the probability of this phytosterol being a mixture containing some stigmasterol. The above-described acetyl derivative was therefore treated with bromine in the manner described by Windaus and Heuth (Ber., 1906, 39, 4378; 1907, 40, 3681), when a crystalline bromo-derivative rapidly separated. On recrystallising the latter from a mixture of chloroform and alcohol, small, glistening crystals, melting at 210°, were obtained, which were identified as tetrabromoacetylstigmasterol. When denomin¬ ated by means of zinc dust, the above compound yielded acetyl- stigmasterol (m. p. 140°), and the latter, on hydrolysis, was con¬ verted into stigmasterol, melting at 167°. The mother liquors from the crude tetrabromoacetylstigmasterol, when debrominated in a similar manner, and subsequently hydrolysed, yielded a small amount of a phytosterol, which, after recrystallisation, melted at 133°, and was probably sitosterol, but the amount obtained was not sufficient for its identity to be fully confirmed. Ethereal Extract of the Resin.—The ethereal extract of the resin was dark brown, and amounted to 87‘4 grams. It was digested with a litre of ether, when a portion of it, which remained un¬ dissolved, was removed by filtration. The ethereal solution was then shaken with 10 per cent, hydrochloric acid, when a quantity of an alkaloid was removed. The acid extracts wrere then rendered alkaline by means of sodium carbonate, and extracted, first with ether and subsequently with chloroform, since a portion of the alkaloid was only with great difficulty removed bv the former solvent. On evaporating the chloroform extract, an amorphous, basic product was obtained, which will be referred to later, but the ethereal extracts, when evaporated to a moderately small volume, deposited a quantity (0-15 gram) of light, feathery needles.