The constituents of the leaves of prunus serotina / by Frederick B. Power and Charles W. Moore.
- Frederick Belding Power
- Date:
- [1910?]
Licence: In copyright
Credit: The constituents of the leaves of prunus serotina / by Frederick B. Power and Charles W. Moore. Source: Wellcome Collection.
12/18 page 1108
![above-described brown powder had been separated by filtration, was thoroughly extracted with successive portions of amyl alcohol. These extracts were united, washed with water, and concentrated under diminished pressure to a syrupy consistency. The dark- coloured residue thus obtained was dissolved in a small quantity of hot ethyl alcohol, and the solution kept for some time, when a substance was deposited in light yellow needles. This was collected, washed with a little alcohol, and recrystallised, first from alcohol, and then from dilute pyridine, when it separated in golden-yellow leaflets, melting at 245°. The amount of substance so obtained was 4 grams: 0*3270 of air-dried substance, when heated at 125°, lost 0‘0347 H20. H20 = 10*6. 0*1505 * gave 0*2994 C02 and 0*0620 H20. C = 54*3; H = 4‘5. C21H20O12 requires C = 54*3; H = 4*3 per cent. C21H20O12,3H2O requires H2O = 10*4 per cent. The anhydrous substance, on exposure to the air, readily takes up its three molecules of water of crystallisation: 0*5340 of anhydrous substance absorbed 0*0640 H20. H2O = 12‘0. C2iH20O]2, to form C21H20O12,3H2O, requires H20 = ll*6 per cent. The glucosidic character of the substance was ascertained by boiling it for a few minutes with 5 per cent, aqueous sulphuric acid. The products thus obtained were quercetin, C15H10O7, and a sugar, the latter yielding <7-phenylglucosazone, melting at 205—208°: 0*7410 of anhydrous substance gave, on hydrolysis, 0*4785 of quercetin. C15H10O7 = 64*6. C2iH20O12 requires C15H10O7 = 65*1 per cent. The quercetin thus obtained was identified by its analysis (Found, C = 59*6; H = 3*7. Calc., C = 59*6; H = 3*3 per cent.), and also by that of its acetyl derivative (Found, C = 58*6; H=4*l. Calc., C = 58*6; H = 3*9 per cent.). From these results it is evident that the above-described substance is a glucoside of quercetin. It was thought that it might be identi¬ cal with a glucoside recently isolated by A. G. Perkin (Trans., 1909, 95, 2181) from cotton flowers, and designated quercimeritrin, since the latter possesses the formula C21H20O12,3H2O, melts at 247—249°, and yields quercetin on hydrolysis. Through the courtesy of Professor A. G. Perkin, who had kindly supplied us with a specimen of quercimeritrin, it was possible to compare the two substances, and they were found not to be identical. The above-described glucoside is more readily soluble in water, and also more readily hydrolysed, than quercimeritrin. Furthermore, on * Dried at 125°.](https://iiif.wellcomecollection.org/image/b30616839_0012.jp2/full/800%2C/0/default.jpg)
