Chemical examination of the root of ipomoea orizabensis / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1912?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of the root of ipomoea orizabensis / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

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    mining their identity and purity (compare Guigues, Chem. Zentr., 1907, I., p. 309; also Power and Rogerson, Amer. J. Pharm., 1908, 80, 251, and J. Amer. Chem. Soc., 1910, 32, 85), it was deemed of interest to ascertain the optical rotation of the resin under investi¬ gation. For this purpose a portion of the resin obtained by the previously mentioned assay of the root was first employed. It was dissolved in absolute alcohol, and the solution heated with succes¬ sive small portions of animal charcoal until nearly deprived of colour. The initial rotation of this solution in a 1-dcm. tube was — l^l7, and since the amount of resin in 5 c.c. of the liquid was 0'4022 gram, therefore [a|D = — 23'0°. Another determination was made, with the use of a little of the above-described resin (B), which gave the following result: A solution in absolute alcohol, of which 5 c.c. contained 0’2386 gram of resin, gave [a]D —1°6/ in a 1-dcm. tube, whence [a]D -23-05°. Guigues (loc. cit.) considers the specific rotation of the resin from Ijpomoea orizabensis to be within the limits of — 23’5° and —25°, and Kromer (Chem. Centr., 1895, II., p. 228) has observed for purified “ jalapin ” the values — 22'84° to — 23'83°. The resin of scammony root, which, as previously noted, has been considered to be identical with “ jalapin ” (from Ipomoea orizabensis), has been stated by Guigues {Bull. Soc. chim., 1908, [iv], 3, 872) to have an optical rotation varying from —18’5° to —23‘5° (Kromer, loc. cit., states — 23‘06°), whilst the resin extracted from the gum-resin scammony has a maximum value of —24*5°. Goris and Fluteaux {Bull. Sci. Pharmacol., 1910, 17, 15j have observed for the last- mentioned product a specific rotation of — 24°26/. Preliminary Extraction of the Crude Resin with different Solvents. In order to ascertain the general characters of the crude resin, a small portion (10 grams) of it was dissolved in alcohol, mixed with purified sawdust, and the thoroughly dried mixture extracted successively in a Soxhlet apparatus with various solvents. The amounts of extract, dried at 100°, were as follows: Peti oleum (b. p. 40- -60°) extracted 6-2 Ether J > 64-8 Chloroform J > 0-6 Ethyl acetate 5 > 24-8 Alcohol 2-3 Loss 1-3 100’0 per cent. For the purpose of a complete examination, 1142 grams of the resin were employed. This was dissolved in alcohol, mixed with