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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    acid, C16H3203. (Found, C = 70'5j H = 11‘8. Calc., C = 70'6; H = 11‘7 per cent.) A large amount of this acid had previously been obtained from the ethereal extract of the original resin after alkaline hydrolysis and extraction with ethyl acetate. By the subsequent extraction of the above-mentioned mixture with ether, a further quantity (about 2 grams) of an acidic product was obtained, which was dark in colour. It was therefore purified by conversion into its methyl ester, which distilled at 220/20 mm., and, after crystallisation from ethyl acetate, melted at 47—49°. The portion of acidic product removed by ether was thus shown to consist of impure jalapinolic acid. The above-described yellow aqueous liquid, which had been extracted with ether, was finally treated with barium hydroxide for the removal of the sulphuric acid, and, after filtration, was concentrated under diminished pressure. It then yielded an osazone, which separated from dilute pyridine in clusters of fine needles, melting at 180—182°, and was doubtless a derivative of the previously described methylpentose. No dextrose was present in the liquid. Alcohol Extract of the Hydrolysed Resin (IV). This was an amorphous solid, which amounted to 100 grams, and, after treatment with animal charcoal, was obtained as a perfectly white powder. It was readily soluble in water, and did not reduce Fehling’s solution until after heating with an acid. It was optically active, and a determination of its specific rotatory power gave the following result: A solution, of which 5 c.c. gave on evaporation 0‘3200 gram of substance, dried at 110°, had aD — 4°26' in a 2-dcm. tube, whence [a]D — 34-64°. Treatment with Dilute Sulphuric Acid.—Seventy grams of the above-described product were dissolved in water, and such an amount of dilute sulphuric acid added as to form 1200 grams of solution containing 5 per cent, of acid. The whole was then heated in a reflux apparatus for about four hours, after which it was distilled in a current of steam. The only volatile products obtained by this treatment were a little oil giving the colour reaction of furfuraldehyde and a small amount of formic acid. After the above operation there remained in the distillation flask a dark yellow liquid and a quantity of solid substance floating on the surface. The whole was extracted with ether, and the ethereal liquid shaken with aqueous sodium carbonate. On evaporating the ether, a small amount of substance was obtained, which, when crystallised from ethyl acetate, separated in leaflets melting at