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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    potassium hydroxide. previously mentioned were small in amount, and amorphous. After the extraction with these alkalis, the ether only contained a small amount of indefinite, fatty matter. A portion of the original aqueous liquid (A) which had been extracted with ether, as previously described, was extracted many times with amyl alcohol, but it was found that the product so re¬ moved was chiefly of an alkaloidal nature, and was slowly extracted from the amyl alcohol by means of aqueous hydrochloric acid. The portion of the amyl alcohol extract which was not basic was small in amount, and amorphous. Nothing definite could be obtained from it by either acid or alkaline hydrolysis. It was subsequently found that the alkaloid remaining in the aqueous liquid after extraction with ether could be more conveniently removed by means of chloroform, and this method was therefore resorted to. Isolation of Colchicine, C^H^O^N.—1The chloroform extract of the aqueous liquid gave a crystalline substance containing chloro¬ form of crystallisation. When deprived of the solvent, the sub¬ stance was amorphous. It could not conveniently be recrystallised from chloroform owing to its great solubility, but was .eventually obtained crystalline from ethyl acetate. The product so obtained was then readily recrystallised from the last-mentioned solvent when dry, when it formed aggregates of small, soft needles, having a very pale yellow colour, and melting at 155 157°: 0*5813* on drying in a vacuum lost 0*0086 TLO. IT.,0 — 1-5. 0*1008 f gave 0-2428 CO, and Q-0620 H,0. C = 65*7~; 11 = 6-8. 03024 f ,, 97 c.c. N2 (moist) at 19° and 772 mm. N = 3*7. 0 1967 f „ 0-4561 Agl. MeO = 30 6. C22H25°(>N requires C = 66‘2; 11 = 6-3; N = 3*5; 40Me = 3M per cent. The properties and composition of this alkaloid suggested that it was colchicine, and, apart from the differences mentioned below, it was found to yield the reactions characteristic of the latter, as described in the United States Pharmacopoeia. The colchicine, however, which is obtained from the corrn or seeds of Colchicu m autumnalct Linn., is described as an amorphous powder, melting at 142°, and has only been obtained crystalline in the form of a chloroform compound, containing three molecules of chloroform of crystallisation. For the sake of comparison, therefore, colchicine isolated from Colchicnm antn//male was also investigated, and found to crystallise from ethyl acetate in soft, pale yellow needles, melting at 155—157°, alone or when mixed with the base derived from Gloriom superha. With the object of further confirming the * Air-dried. -f- Dried in a vacuum.