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.

    19/30 (page 17)
    3'5518, made up to 20 c.c. with chloroform, gave aD +0°17/ in a 2-dcm. tube, whence [a]D+0'79°. (b) Ethereal Extract.—The acid extracted by ether was dark in colour, and amounted to 12 grams. It was purified by conversion into its methyl ester, and found to consist only of jalapinolic acid. Identification of Dextrose and a Methylpentose. The aqueous acid liquid resulting from the acid hydrolysis of the ethyl acetate extract of the hydrolysed resin, which had been extracted with ether as above described, was subsequently treated with barium hydroxide for the removal of the sulphuric acid, the mixture filtered, and the filtrate evaporated under diminished pressure to the consistency of a syrup. This syrup readily reduced Fehling's solution, and yielded an osazone, melting at 203—205°, which was evidently d-phenylglucosazone. In order to obtain more definite information respecting the character of the sugar produced by the above-mentioned hydrolysis, the syrup was heated with acetic anhydride in the presence of a trace of d-camphorsulphonic acid. A vigorous reaction ensued, and after this had subsided the mixture was cooled, poured into water, and the liquid extracted with ether. The ethereal liquid was washed, dried, and the solvent removed, when a quantity of a light-coloured syrup remained, which was dissolved in dilute alcohol. After keeping for a few days a crystalline substance separated, which was collected and recrystallised from 70 per cent, alcohol, when it was deposited in handsome, prismatic needles, melting at 142—143°. It was anhydrous, and gave on analysis the following results: 0-2466 gave 0-4582 C02 and 0T358 H20. 0 = 50-6; H = 61. 0-1070 „ 0-1986 C02 „ 0-0606 H20. C = 50-6; H = 6*3. C14H20O9 requires C = 506; 11 = 6-0 per cent. The above-described substance is thus seen to be a tetra-acetyl- methylpentose, CGH805(C0*CIl3)4, and it is apparently a new compound. A determination of its optical rotatory power gave the following result: Methyl convolvulinolate, C^H^fOHpCO^CHg (m. p. 32—33°) .- 2-0142, made up to 20 c.c. with chloroform, gave aD + 0°19' in a 2-dcm. tube, whence [a]D + l'57°. Ipurolic acid, C13H.5(0H)2*C02H (m. p. 100—101°). No rotation could be measured with a solution of 2-6068 of the acid in 20 c.c. of absolute alcohol. Methyl ipurolate, C^H^fOHVCOa’CHg (m.p. 68—69°): 0-6900, made up to 20 c.c. with absolute alcohol, gave a^ + O0?' in a 2-dcm. tube, whence [a]D+1 69°.