The constituents of the bark of "Prunus serotina" / by Frederick B. Power and Charles W. Moore.
- Frederick Belding Power
- Date:
- [1909?]
Licence: In copyright
Credit: The constituents of the bark of "Prunus serotina" / by Frederick B. Power and Charles W. Moore. Source: Wellcome Collection.
14/24 page 254
![of considerable interest from the fact that, so far as known to us, it is the first instance in which its occurrence in nature has been observed. Further confirmation of the identity of the above substance was afforded by the preparation of some derivatives, a determination of the number of methoxyl groups, and its molecular weight. The methyl ester was prepared in the usual manner, and, as this can be volatilised with steam, it affords a ready method for the purification of the acid. When crystallised from water, it separated in long needles melting at 84° : 0-2098 gave 0*4485 C02 and 0*1190 H20. 0 = 58*3; H = 6*3. CnH1405 requires C = 58*4 ; H = 6*2 per cent. The acid was regenerated from this ester, and crystallised from ethyl acetate, when it melted at 167—169°, as before, and was again analysed : 0*1287 gave 0 2680 C02 and 0*0685 H20. 0 = 56*8 ; H = 5*9. Ci0Hi2O5 requires 0 = 56*6 ; H = 5*6 per cent. The silver salt was obtained as a crystalline precipitate by the addition of silver nitrate to a solution of the ammonium salt. It was washed with a little cold water, dried in a vacuum over sulphuric acid, and analysed : 0*5070 gave, on ignition, 0*1710 Ag. Ag = 33*7. CioHn05Ag requires Ag = 33*8 per cent. A determination of the number of methoxyl groups in the acid by Perkin’s modification of the Zeisel method gave the following result : 0*1316 gave 0*4370 Agl. OMe = 43*8. C7H302(0Me)3 requires OMe = 43*9 per cent. The molecular weight of the acid was determined by the cryoscopic method in acetic acid solution : 0*2965 in 22*2415 of acetic acid gave At - 0*254°. M.W. = 201, C]0Hi2O5 requires M.W. = 212. Isolation of ip-Coumaric Acid. After the removal of the trimethylgallic acid from the ethereal liquid by the first three extractions of the latter with aqueous ammonium carbonate, as above described, the subsequent extractions with this alkali gave, when acidified, about 8 grams of a product melting at 210—213° with evolution of carbon dioxide. This was recrystallised from hot water, from which it separated in small, colour¬ less needles melting, as before, at 210—213° : 0*1580 gave 0*3810 C02 and 0*0690 H20. C = 65*8 ; H = 4*9, C^HgOg requires 0 = 65*9 ; H = 4*9 per cent,](https://iiif.wellcomecollection.org/image/b30614375_0014.jp2/full/800%2C/0/default.jpg)
