Chemical examination of cotton-root bark / by Frederick B. power and Henry Browning, Jun.

  • Frederick Belding Power
Date:
1914.]
Catalogue details

Licence: Public Domain Mark

Credit: Chemical examination of cotton-root bark / by Frederick B. power and Henry Browning, Jun. Source: Wellcome Collection.

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    Another portion (20 Gms.) of material was extracted suc¬ cessively in a Soxhlet apparatus with various solvents, when the following amounts of extract, dried in a water-oven, were obtained :— Petroleum (b.p. 35-50°) extracted 0'70 gramme = 3'50 per cent. Ether . ,, 0*35 ,, = 1-75 Chloroform... ,, 0-80 ,, = 4-00 Ethyl acetate. ,, 0‘60 ,, = 3-00 Alcohol. ,, 1*53 ,, = 7 65 Totaf. 3'98 grammes = 19'9 per cent. For the purpose of a complete examination of the con¬ stituents of the bark 21‘66 kilos of the air-dried ground material were completely extracted with hot alcohol. After the removal of the greater portion of the alcohol 3'07 kilos of a viscid, dark-red extract were obtained. Distillation of the Extract with Steam. Separation of an Essential Oil. The entire amount of the alcoholic extract was mixed with water and subjected to distillation in a current of steam. On extracting the distillate with ether a very small quantity '(2'2 Gms.) of a pale yellow essential oil was obtained, and a further small amount (about 5 Gms.) of the same product was subsequently obtained on working up a somewhat larger quantity of the bark in the above-described manner. The essential oil, when separately distilled, passed over chiefly between 120 and 135° at the ordinary atmospheric pressure. It gave the colour reaction of furfuraldehyde. When kept for a short- time it deposited a few small crystals, which, after recrystallisation from ethyl acetate, were obtained in faintly yellow needles, melting at 112-114°. This sub¬ stance possessed the characters of acetovanillone, and no depres¬ sion of the melting-point ensued when mixed with the latter, but the amount was too small to permit of its more complete identification. After the above-described treatment there remained in the distillation flask a dark-brown aqueous liquid (A) and a con¬ siderable quantity of a deep purplish-coloured resin (B). The resin was granular in character, and after being washed and dried amounted to 2300 Gms., thus corresponding to 10‘6 per cent, of the weight of bark employed. Examination of the Aqueous Liquid (A). The aqueous liquid, after concentration under diminished pressure, was extracted many times with ether, the ethereal extract being then successively shaken with aqueous ammonium carbonate, sodium carbonate, and sodium hydroxide. For the more complete examination of the products thus obtained, a larger quantity of bark was subsequently employed. The acid material removed by the ammonium
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