Chemical examination of the tuberous root of ipomœa horsfalliæ / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of the tuberous root of ipomœa horsfalliæ / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

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    The root was sliced, and then dried in a water-oven, when it weighed 408 grammes, the loss of weight in drying having thus been 1987 grammes, or nearly 83 per cent. The dried material was ground to a fine powder, when it amounted to 385 grammes. It was then brought into a large Soxhlet apparatus, and thoroughly extracted with hot alcohol, the greater portion of the alcohol being subsequently removed, and the resulting extract distilled in a cur¬ rent of steam. The distillate was found to contain only traces of formic and butyric acids. After the above-described treatment, the contents of the distil¬ lation flask consisted of a dark red, aqueous liquid, together with a small amount of resinous material. The liquid was filtered, and the resin repeatedly washed with hot water, after which the resin was dissolved in a little alcohol, the solution evaporated to dryness, and the residue dried at 100° C. The amount of resin obtained was 9.6 grammes, thus corresponding to 2.5 per cent, of the weight of dried, or 0.4 per cent, of the weight of the entire fresh root. The resin formed a dark brown, spongy mass, which became somewhat sticky on exposure to the air. It was found to be almost completely soluble in ether. Optical Rotation of the Crude Resin. The optical rotatory power of the convolvulaceous resins has been considered to afiford some indication of their identity or purity.^ As this factor has previously been determined for several such resins, including those of Ipomcea purpurea, Roth, and jalap by the present authors,^ it was deemed of interest to make this determina¬ tion with the resin under examination. For this purpose i.o gramme of the crude resin was dissolved in absolute alcohol, and the solution treated with successive small quantities of animal charcoal until it was nearly deprived of color. The rotation of this liquid in a 2 dcm. tube was —o°54', and the amount of substance contained in 10 c.c. of the liquid, after drying at 105-10° C., was 0.1584 gramme, whence [a]^—28.4°. It may be noted that this degree of optical ^Compare Giiigues, dc Pharni. et de Chtni., [6], 22, 241, and Cliem. Centralblatt, 1907, Bd. 7, p. 309. Also Bull soc. chim. [4], 3. 872, (1908). ’This Journal, 1908, 80, p. 253, and Journ. Avier. Cheni. Soc., igio, 32, p. 85.