Analysis of the Leaves of Ceanothus Americanus, Linne.
BY J. H. M. CLINCH, PH.G.
From an Inaugural Essay.
Five grams of the air-dry leaves subjected to a heat of 100°C. until they ceased to lose weight, weighed 4.455 grams, showing a loss of .545 grams = 10.9 per cent. amount of moisture.
Forty grams of the air-dry leaves were incinerated and yielded 1.895 grams of ash = 5.31 per cent., of which 50.526 per cent. was soluble in water, 48.629 per cent. was soluble in hydrochloric acid, .8 per cent. was soluble in boiling sodic hydrate. An analysis showed the presence of potassium, calcium, magnesium, aluminium, iron and silica, combined as chlorides and sulphates in the aqueous solution, and as phosphates, sulphates, and carbonates in the hydrochloric acid solution (the iron may have been derived from the mill during grinding).
Thirty grams of the powdered air-dry leaves were exhausted with pure benzol and the liquid allowed to evaporate spontaneously, yielding an extract weighing 1.507 grams = 5.64 per cent. This was treated with warm water, allowed to cool, filtered, and the filtrate tested for alkaloids and glucosides with negative results. The undissolved extract was treated with water acidulated with sulphuric acid, filtered, and the filtrate tested for alkaloids; gave a grayish precipitate with potassio-mercuric iodide, and a bright yellow precipitate with phosphomolybdic acid; negative results for glucosides. The residue was washed well with water to free from sulphuric acid, and treated with absolute alcohol; the solution was filtered, treated with animal charcoal, filtered again and evaporated, leaving a pale yellowish mass of a soft and tough consistence. It has an acid reaction, is soluble in ether, benzol, volatile oils, partly soluble in aqueous alkalies, soluble in strong sulphuric acid with a red color, and has a peculiar odor and somewhat acrid taste.
This appears to be a resin mixed with a small quantity of fixed oil, as the portion left on treatment with 80 per cent. alcohol, when boiled with potassa, was precipitated by chloride of sodium as a soap. The residue of the benzol extract after treatment with absolute alcohol consisted of wax with a small amount of coloring matter.
The drug exhausted with benzol was dried and exhausted with stronger alcohol, the extract which weighed 5.801 grams = 21.72 per cent. was treated with absolute alcohol and the soluble portion with distilled water. This solution had an acid reaction, and gave a yellow precipitate with subacetate of lead, which after decomposing with hydrosulphuric acid yielded a filtrate reducing Fehling's solution on heating, and gave a green color with ferric chloride, and a reddish brown color with solution of potassa, showing the presence of an "iron-greening" tannin. A concentrated solution failed to give precipitates with solutions of gelatin and tartrate of antimony and potassium, but gave precipitates with cinchonine and quinine, and reduced nitrate of silver in the specular form when heated. These reactions appear to indicate that it is identical with or closely related to caffetannic acid.
The filtrate from the precipitate by subacetate of lead was freed from lead by H2S and concentrated. Phosphomolybdic acid and potassio-mercuric iodide failed to produce precipitates, but Fehling's solution was reduced without heat (glucose). The remaining solution was evaporated to dryness; the residue had very little odor, and at first a sweet taste, passing into that of pop-corn, and was considered to be glucose and extractive matter.
The alcoholic extract insoluble in water gave with dilute sulphuric acid a nitrate in which phosphomolybdic acid and potassio-mercuric iodide gave precipitates the same as in acid solution of benzol extract, and negative results for glucosides.
The alcoholic extract insoluble in dilute sulphuric acid, was entirely soluble in dilute ammonic hydrate and reprecipitated by an acid; it was blackish brown, brittle, opaque, inodorous and tasteless, and in concentrated alcoholic solution had an acid reaction. It was partly soluble in boiling water, not wholly precipitated on cooling, and partly soluble in ether, the solution having a green color; it is an acid resin mixed with coloring matter, and in alcoholic solution gives a precipitate with lead acetate and a green color with ferric salts. That portion of the alcoholic extract which was insoluble in alcohol was found to consist of some coloring and extractive matter.
The leaves previously exhausted with benzol and alcohol, yielded to cold water 12.795 per cent. of extract containing gummy and coloring matter. A decoction of the leaves did not become blue with iodine. 8 pounds of the air-dry leaves distilled with water yielded about 10 grains of a light yellow oil having a strong aromatic odor and a distinct acid reaction.
The precipitates obtained with the benzol and with the alcohol extract by potassio-mercuric iodide were separately treated with stannous chloride and potassa; on exhausting with ether and evaporating, minute apparently crystalline residues were obtained which were not further examined.
The American Journal of Pharmacy, Vol. 56, 1884, was edited by John M. Maisch.