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.

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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    Oxidation of the Ethyl Acetate Extract of the Hydrolysed Resin -with Nitric Acid. A quantity (25 grams) of the previously-described ethyl acetate extract of the hydrolysed -esin was dissolved in a little water, and to the solution, contained in a flask provided with a reflux condenser, 200 grams of nitric acid (D 14) were added. The mixture was then gently warmed, when a vigorous reaction ensued, and after this had ceased the heating was continued for a short time. About 200 c.c. of water were subsequently added, the mixture boiled for ten minutes, and tlieu distilled in a current of steam. The distillate was rendered alkaline with sodium carbonate, concentrated to a small bulk,’then acidified with hydrochloric acid, and extracted with ether, the ethereal liquid being washed, dried, and the solvent removed. A small amount (T2 grams) of a liquid acid was thus obtained, which, when distilled under the ordinary pressure, passed over between 190c and 195° as a colourless oil, and was dextro- rotatory : 0’1578 gave 0'3494 C02 and 0'1434 H20. C = 60'3; H = 10'l. C5II]0O2requires C = 58'8; H = 9'8 per cent. C6H1202 „ C = 62'0; H = 10'3 „ „ A portion of the acid was converted into a silver salt, which was precipitated in three fractions, and these were analysed: (а) 0-3020 gave 0’1456 Ag. Ag = 482. (б) 0-2962 „ 0-1440 Ag. Ag = 48'6. (c) 0-2320 „ 0-1180 Ag. Ag = 50‘9. CcHoOgAg requires Ag = 51 7 per cent. C6Hn02Ag „ Ag = 48‘4 „ „ It would thus appear that the volatile acid formed by the oxida- tion consisted of a mixture of optically active valeric acid and a hexoic acid. The aqueous acid liquid remaining in the distillation flask deposited a white solid on cooling. The mixture was accordingly extracted with ether, and the ethereal liquid shaken with aqueous sodium carbonate, which removed all of the dissolved substance. On subsequently acidifying the alkaline liquid and extracting with ether, it yielded a quantity (3 grams) of a solid acid, which was fractionally crystallised, first from dilute acetic acid, and finally from the glacial acid. Four fractions were thus obtained, which melted at 125—127°, 115—117°, 104—107°, and 84—90° respec- tively. After drying in a vacuum and then at 120°, they were analysed: