Compounds Of Pharmaceutical Interest Research Articles

Khellin. Part II. Methods for the determination of two principles isolated from Ammi visnaga lam

Since khellin, visnagin, and khellol-glucoside, isolated from the plant Ammi visnaga Lam., have been proved to be compounds of pharmaceutical interest, it was necessary to devise methofs for their quantitative determination, either singly or in mixtures. Because the glucoside was easily removed from the samples tested, our work was limited to a study of khellin and visnagin. A review of the literature revealed two colorimetric methods, using potassium hydroxide or sulfuric acid to develop the color. It was found, however, that these two methods lacked reproducibility and failed to distinguish between khellin and visnagin. To solve this problem several new methods were developed using ultraviolet, infrared, and polarographic techniques. The ultraviolet and polarograhic methods were found to give reproducible results on the determination of khellin, visnagin, or mixtures of both, when the results were reported in terms of a standard compound. It was also found possible to determine the ratio of khellin to visnagia in mixtures of the two by means of infrared absorption, and by use of these data, to translate the ultraviolet or polarographic results into absolute quantities of each component. Both methods were satisfactory, but the ultraviolet was preferred because of its brevity and simplicity.