Chemical examination of watermelon seed / by Frederick H. Power and Arthur H. Salway.

  • Power, Frederick B. (Frederick Belding), 1853-1927.
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of watermelon seed / by Frederick H. Power and Arthur H. Salway. Source: Wellcome Collection.

    12/20 (page 368)
    tion, therefore, of the source and alcoholic nature of the new compound, it is proposed to designate it cucurbitol. It is of interest to note, in this connection, that two substances of alco¬ holic nature, which appear to be closely related to cucurbitol, have re¬ cently been isolated in these laboratories. One of these was obtained from the resin of Grindelia camporum, Greene, and agrees in composi¬ tion with the formula C23H3804. It melts at 256-257°, and yields an acetyl derivative melting at 1610.1 This compound, which was not previously named, may now be conveniently designated grindelol. The other substance was obtained from jalap resin and possesses the formula C2iH340,2 The latter compound, designated ipurganol, melts at 222- 225° and yields an acetyl derivative melting at 166-167°. The three substances, cucurbitol, grindelol, and ipurganol, show slight differences in their color reactions when subjected to the above-mentioned test in chloroform solution with acetic anhydride and concentrated sulphuric acid. Thus ipurganol gives at first a purplish pink coloration, chang¬ ing to blue, then becoming bright green, and finally brown, while grin¬ delol gives at first a blue color, which changes to a duller green than the preceding, and finally becomes brown, and in the case of cucurbitol the intermediate greenish tint is still less pronounced. In view of the com¬ position and character of these three new compounds, it is evident that they are members of a homologous series, which is represented by the general formula CwH2w_804. Chloroform, Ethyl Acetate and Alcohol Extracts of the Resin. The chloroform and ethyl acetate extracts were both very small in amount (3.0 and 2.2 grams respectively), and, like the alcohol extract of the resin,. formed brittle, black solids. They were all carefully ex¬ amined, but nothing definite could be isolated from them. III. Examination of the Shells. The shells from 22.5 kilograms of watermelon seeds amounted to 10.95 kilograms, thus corresponding to 48.7 per cent, of the weight of the seed. This material was ground and extracted by continuous percolation with hot alcohol. After the removal of the greater portion of the alcohol, a dark-colored, oily product was obtained, which contained some resin in suspension. The entire amount of extract (907 grams) was first mixed with a large volume of light petroleum, in order to effect the separation of the fatty oil (A). The portion of extract remaining undissolved by the petroleum may be designated as (B). The Fatty Oil (A). The petroleum solution of the fatty oil was filtered, dried with anhy- 1 Compare Proc. Am. Pharm. .Aj-joc., 55, 342 (1907). * This Journal, 32, 89.