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

  • Power, Frederick B. (Frederick Belding), 1853-1927
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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    Isolation of a New, Yellow, Phenolic Substance, C1sH1#03(0H), The later washings of the ethereal extract of the aqueous liquid (A) with sodium carbonate, and also with aqueous sodium hydroxide, were of a deep purple colour. The inten¬ sity of colour was but slightly diminished after many extrac¬ tions with the first-mentioned alkali, but the substance pro¬ ducing the colour was rapidly removed by sodium hydroxide. These two alkaline liquids, when acidified and extracted with ether, yielded small amounts ot crystalline yellow products, which were similar in appearance. After numerous crystallisa¬ tions from dilute alcohol and dilute acetone a substance was obtained in slender, orange-yellow needles, melting at 210- 212°. The mother-liquors from the latter yielded a further small amount of substance in the form of brown hexagonal plates, melting at 214-217°. These crystals, although different in appearance from the yellow needles, were found to be identical with the latter. This was indicated by a deter¬ mination of their molecular weight by the microscopic method (mean value in acetone solution = 263; compare result below) and by the fact that when subsequently removed from the solu¬ tion the substance was obtained in the yellow, needle-shaped form. The substance in the form of yellow needles was dried at 115° without any loss in weight. Its analysis and a deter¬ mination of the molecular weight by the microscopic method gave the following results :— 0'0648 gave 0T464 C02 and 0 0447 H20. C = 61*6; H =7*7 0 0364 ,, 0-0813 CO-2 ,, 0 0248 H20. 0 = 60*9; H= 7*6 0*0534, in 7 Cc. of acetone, was between 0‘0275 and 0‘03 mol., using benzil as the standard. Mean M.W. = 266. C13H1BO5 requires C = 6T4 ; H =7T per cent. M.W. = 254. A small portion of the substance was converted into an acetyl derivative by heating with acetic anhydride in the presence of a little pyridine. This derivative separated from alcohol in small, nearly colourless tabular crystals/ melting at 147-149°. It was dried at 110° and analysed. 0*0732 gave 0*1621 C02 and 0’0410 H20. C - 60 4 ; H = 6*2 C13H1#03(0.C0.CH3),, requires C = 60'4; H = 6'5 per cent. A further small amount of the yellow substance of slightly lower melting-point (207°) was heated with benzoyl chloride in the presence of a little pyridine. The product, when crystallised from alcohol, separated in small nodules, melting at 153-157°, but the amount was not sufficient for analysis. The original yellow substance gave with ferric chloride solution a brown tint. With the alkali carbonates and hydroxides, with lead acetate and barium acetate, and also with concentrated sulphuric acid, a deep purple colour was produced. These characters suggested that the substance