The constituents of hops / Frederick B. Power, Frank Tutin and Harold Rogerson.
- Frederick Belding Power
- Date:
- [1913?]
Licence: Public Domain Mark
Credit: The constituents of hops / Frederick B. Power, Frank Tutin and Harold Rogerson. Source: Wellcome Collection.
17/30 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 C02 and 0*0586 ELO. 0-48*6; H-8*3. C6H1204 requires C — 48'6; H —8*1 per cent. This acid was thus identified as a/3-dihydroxyfsohexoic acid, CH3*CH(CH3)-CH(0H)-CH(0H)*C02H, which has been described by Braun (Monatsh., 1896, 17, 216) as melting at 108°. On oxidation with chromic acid, it yielded ?'sobutyric acid. From the results of the above-described oxidation, it is evident that the hexenoic acid contained in hops is /3-?’sopropylacrylic acid, CH3*CH(CH3),CH!CH*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, C33Hr,6Of). 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, first 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 pyridine, 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 in colourless, microscopic crystals, melting at 285—290°: 0*1147 gave 0*3039 C02 and 0T084 H20. C = 72*3; H = 10*5. CggH^Og requires C = 72*3; H —10*2 per cent. 0*1918, made up to 20 c.c. with pyridine, gave aD — 0°37/ in a 2-dcm. tube, whence [a]D —32*1°. This substance was thus identified as a phytosterolin, or phyto¬ sterol glucoside (compare Power and Salway, this vol., p. 399).](https://iiif.wellcomecollection.org/image/b30620387_0017.jp2/full/800%2C/0/default.jpg)
