The constituents of taraxacum root / by Frederick B. Power and Henry Browning, jun.

  • Frederick Belding Power
Date:
1912
Catalogue details

Licence: In copyright

Credit: The constituents of taraxacum root / by Frederick B. Power and Henry Browning, jun. 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.

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    A determination of its optical rotatory power gave the following result: 0 0989, made up to 20 c.c. with chloroform, gave av +0°15/ in a 2-dcm. tube, whence [a]D +25'3°. A cctylhomotaraxastcrol, C^H^O-CO-CH.).—This compound wag prepared by heating the respective alcohol with acetic anhydride. It separated from a mixture of ethyl acetate and alcohol in small, colourless needles, melting at 219—220°: 0-0654 gave 0'1943 C02 and 0-0645 H20. C = 81'0; H = 109. C27H4202 requires C = 81'4; H = 10‘5 per cent. 0'0888, made up to 20 c.c. with chloroform, gave aD +0oI5' in a 2-dcm. tube, whence [a]D + 28T0. A very small portion of homotaraxasterol was converted into its benzoyl derivative, which separated from a mixture of chloroform and alcohol in small, flat needles, melting at 202°. The amount of this compound was not sufficient for analysis. Ether Extract of the Resin. This extract was considerably concentrated in volume and kept for some time, when a small amount of a sparingly soluble grey substance was deposited. This was collected, and the clear, ethereal liquid then extracted successively with aqueous ammonium carbon- ate and sodium carbonate, which, however, removed only traces of brown, amorphous material. The ethereal liquid was finally extracted with aqueous potassium hydroxide, and the alkaline liquid acidified and extracted with ether, which removed some amorphous material, and at the same time an emulsion was formed. This was separated, washed with a little ether, and the latter removed by a current of air, when, on filtration, a further small amount of the above-mentioned grey substance was obtained. The ethereal liquid which had been extracted with alkalis, when dried and evaporated, also yielded a little of the same sparingly soluble grey substance. Isolation of Cluytianol, C29H460(0H)4. The above-described grey substance was first subjected to pro- longed extraction with absolute alcohol in a Soxhlet apparatus. During this operation it was partly deposited in a nearly white condition, and, on finally concentrating the alcoholic liquid, prac- tically all the substance separated. The material thus obtained amounted to 41 grams. It was subsequently heated with acetic anhydride, and the resulting product fractionally crystallised many
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