Drugs and medicines of North America : a publication devoted to the historical and scientific discussion of botany, pharmacy, chemistry and therapeutics of the medical plants of North America, their constituents, products and sophistications.

Date:
1884-1887
Catalogue details

Licence: Public Domain Mark

Credit: Drugs and medicines of North America : a publication devoted to the historical and scientific discussion of botany, pharmacy, chemistry and therapeutics of the medical plants of North America, their constituents, products and sophistications. Source: Wellcome Collection.

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    SUMMARY OF THE ANALYSIS. Percentage Found. Percentage Calculated. Water (H20) 6.52 6.58 per cent. Phosphoric Acid (H3P01) 62.67 62.76 per cent. Berberine (C20H17NO4) 31-56 30.65 per cent. 100.75 99-99 Per cent- These results give C2oHi7N04.7H3P04+4H20, as the formula for phosphate of berberine.* The following equation expresses the reactions: C2JH17N04.H2 S04+6[BaH4(P04)2]=C2oH17N04.7H3P04+BaS04+5BaHP04. This being the only analysis of a compound of phosphoric acid and ber- berine known to us, we deemed it desirable to add further information to this subject. Accordingly, we brought the matter to the attention of Prof. Virgil Coblentz, who agreed to make an ultimate analysis of the compound, and in this connection we call attention to the fact that the salt was made by him by the direct combination of phosphoric acid and crystallized berberine, instead of by double decomposition. We therefore introduce the following report: f Preparation.—(Contributed to this publication by Prof. Virgil Coblentz). An accurately weighed quantity of the pure alkaloid, prepared by Prof. J. U. Lloyd, was dissolved in a sufficient amount of absolute alcohol, and into this solution exactly two grams of phosphoric acid (H3P04) was weighed, the strength of which had been previously ascertained, two grams containing 1.2421 grams of absolute H3P04. Then an equal bulk of absolute ether was added, and after allowing sufficient time for complete sepa- ration the mixture was thrown on a filter paper and the precipitate thoroughly washed with a mixture of alcohol and ether. The filter and contents were then removed and boiled in an excess of alcohol to remove all traces of adher- ing free acid, cooled, and mixed with its bulk of ether. The precipitate that formed was again thrown on a new filter and washed with a mixture of alcohol and ether until it was found to be free from uncombined phosphoric acid. Gravimetric Estimation.—An amount of the alkaloid berberine weighing 0.460 grams was dissolved in absolute alcohol and treated as we have de- scribed. The liquids and washings were mixed and distilled water added ; the ether and alcohol then evaporated by a gentle heat. To this aqueous solution of the free acid, ammonia water in slight excess was added and subsequently test magnesium mixture, until after having been well stirred and permitted to stand, no further precipitate followed the addition of the reagent. Ammonia water equal to one-fourth the volume of the liquid was then added, the vessel covered and allowed to stand for twelve hours. The precipitate of ammonio- * This formula seems, at first sight, an improbable one; but any person who will take the pains to look up the formulae for the phosphates of the other alkaloids, will be surprised at their lack of uniformity, and at the fact that alkaloids exhibit no particular quantivalence.—Parsons and Wrampelmkier. f Prof. F. B. Power is also estimating the composition of phosphate of berberine, using a salt made by us, and crystallized from alcohol. Unfortunately, his report is not ready, and wc will, therefore, present it to our readers at a future day in the Addenda.