The constituents of hops / by Frederick B. Power, Frank Tutin and Harold Rogerson.

  • Frederick Belding Power
Date:
[1913]
Catalogue details

Licence: In copyright

Credit: The constituents of hops / by Frederick B. Power, Frank Tutin and Harold Rogerson. 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.

    17/28 (page 1281)
    another compound, the former predominating. The mixture was therefore converted into the calcium salt, and the calcium oxalate removed and analysed (Found, CaO = 43'6. Calc., CaO = 43‘8 per cent.). The filtrate from the calcium oxalate was acidified, and extracted many times with ether, when, on removal of the solvent, a small amount of a crystalline acid was obtained. The latter, on recrystallisation from benzene containing a little ethyl acetate, separated in colourless leaflets, melting at 109°: 0-0787* gave 0'1404 COg and 0-0586 HgO. C = 48-6; H = 8-3. CgHjgO^ requires C = 48-6; H = 8-l per cent. This acid was thus identifled as ajS-dihydroxyfsohexoic acid, CH3-CH(CH3)-CH(0H)-CH(0H)-C02H, which has been described by Braun Qlonatsh., 1896, 17, 216) as melting at 108°. On oxidation with chromic acid, it yielded isobutyric acid. From the results of the above-described oxidation, it is evident that the hexenoic acid contained in hops is B-^sopropylacrylic acid, CH3*CH(CH3)'CHICH'C02H, a substance which has not previously been known to occur in nature. It has an odour resembling that of valeric acid, but somewhat more rank. Isolation of a Phytosterolin, C33H56O6. The original alkaline solution obtained by the hydrolysis of the petroleum extract of the resin, and from which the volatile acids had been removed, as above described, was shaken with a large volume of ether, when a relatively small quantity of a sparingly soluble solid remained undissolved. This was collected, washed with ether, and then extracted in a Soxhlet apparatus, flrst with ethyl acetate until the chlorophyll was removed, and subsequently for a long time with alcohol. The solid which gradually separated from the latter solvent during the process of extraction was collected, and heated with acetic anhydride containing a little pyrMine, when, on removing the greater part of the solvent, a product was obtained which crystallised from alcohol in colourless leaflets. This was hydrolysed with alcoholic potassium hydroxide, when It yielded^ a substance which separated from dilute pyridine m colourless, microscopic crystals, melting at 285—290°: 0-1147 gave 0-3039 CO2 and 0-1084 HgO. C = 72-3 j H = 10-5. 0.1 Q1Q requires C = 72-3; H = 10-2 per cent. , made up to 20 c.c. with pyridine, gave -0°37' in a 2-dcm. tube, whence [o]j, —32-1°. ‘''“S Mentifiod as a phytosteroliu. or phyto- sterol glucosido (compare Power and Salway, this vol., p. 399). ^