CHROMATOGRAPHIC SEPARATION AND EXTRACTION OF ERGONOVINE

Use was made of buffer-impregnated paper for the separation and indentifica- tion of ergonovine from other ergot alkaloids. It was found that the R_f value of ergonovine depends on the pH value of the buffer used. Paper moistened with a mixture of pH 7 buffer solution, acetone and formamide (2:2:1) gave good results with chloroform as developer. The separation was good and the spots were well defined. It took only about 2 hours to develop the chromatogram. Since the R_f value varies with temperature, amount of aqueous phase on the paper, etc., it is suggested that pure alkaloid be run at the same time as the sample for identifica- tion purpose. The partition chromatography of ergonovine, ergometrinine, ergotoxine and lysergic acid on a celite column with buffer solutions of various pH values was also studied in order to find optimal conditions for the extraction of ergonovine from ergot. With a pH 3.4 buffer solution, lysergic acid and ergonovine stayed on the top of the column while other alkaloids moved down. When the column was eluted with ammonia-saturated chloroform, ergonovine was washed out, thus separated from lysergic acid. From these results, pure ergonovine maleate crystals were obtained from ergot by the following proposed method: Prepare a chromatographic column of celite containing pH 3.4 buffer solution. Extract alkaloids from ergot with chloroform containing methanol and ammonia, acidify the extract to pH 3.4 with 2 N sulfuric acid in ethyl acetate solution. Run this mixture through the column. Ergonovine will stay adsorbed. Elute the column with ammonia-saturated chloroform, distil off the organic solvent under reduced pressure, cool, filter, dissolve the residue in acetone, add a solution of malefic acid in acetone; ergonovine maleate will separate out as pure, white crystals.