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.

    19/32 (page 15)
    with ether, was found to contain a little formic acid, with apparently traces of a valeric acid. After tho removal of the volatile products resulting from the above-described acid hydrolysis, there remained in the distillation flask about 3 litres of a dark yellow liquid, together with a quantity of solid material which floated on the surface. The .vhole was extracted with ether, when all of the solid material passed into solution. On subsequently extracting the ethereal liquid with aqueous sodium carbonate, a quantity of the sodium salt of an organic acid separated, and this was collected. The ethereal liquid was then dried, and the solvent removed, when a small amount (0'5 gram) of a lightcoloured oil remained, which became solid on cooling. This substance was recrystallised from ethyl acetate, when it separated in shining laminae, melting at 45—46°: 0 1250 gave 0’3244 C02 and 0 1350 H20. C = 70'8; H=120. CjyH^jOg requires C = 7T3; H = 11'9 per cent. On heating a portion of the substance with alcoholic potassium hydroxide it was found to become hydrolysed, and an acid was thus obtained, which separated from ethyl acetate in small needles, melting at 67—68°. (Found, O=70'2; H = 11'8. Calc., C = 70'6; H = 11‘7 per cent.) The above-described substance was thus identified as methyl jalapinolate, which had evidently escaped hydrolysis by the preced- ing treatment with dilute sulphuric acid. Small amounts of methyl jalapinolate were subsequently isolated from the various products resulting from the alkaline hydrolysis of the original ethyl acetate extract of the resin. It was therefore deemed of interest to ascertain what proportion of the hydrolysed ethereal extract of the original resin was acidic, as a portion of it evidently consisted of a derivative of methyl jalapinolate. For this purpose a quantity (10 grams) of the hydrolysed resin was acetylated by means of acetic anhydride, the product dissolved in ether, and the ethereal liquid shaken with aqueous potassium hydroxide. By this means 6'7 grams of acidic material were removed, which formed a yellow, amorphous, friable mass, and on subsequently evaporating the ether, 6’4 grams of a neutral, light yellow syrup were obtained. After hydrolysis with barium hydroxide the product from the acidic portion had [a]D -35 7°, whilst that from the neutral portion had [a]D -351°. Both these products, on heating with dilute sulphuric acid, yielded jalapinolic acid and a mixture of sugars, the neutral acetyl derivative also giving a trace of methyl jalapinolate.