Recovery of alkaloids from leaves and seeds of Argemone mexicana

Research work carried out in Sudan on the weed Argemone mexicana L. pointed to the potential of the plant as a source of larvicides against mosquito. Mosquito, Anopheline arabiensis, is on focus in Sudan because of its role as a vector of several tropical diseases. The objectives of this study was evaluation or selection of the best solvent used for extraction of the alkaloids and Identification of the alkaloids using spectroscopy as well as chromatographic methods. The result showed that ethanol was the best for extraction of Argemone leaf alkaloids both qualitatively and quantitatively; hexane the poorest while acetone and chloroform were in between. Ethanol was selected as the best organic solvent for extraction and different water dilutions were used (10%, 25%, 50%, 75%, and 100%). The three alkaloids were detected in all ethanol dilutions. The alkaloid quantity increased with the increase of ethanol %. In addition pure ethanol extract was comparable to distilled water. The three alkaloids detected in different methanol water dilutions (100%, 75%, 50%, and 0%) and 75%& 50 extract the higher concentration of alkaloids. Pure methanol extract was comparable to the distilled water extract. Distilled water extraction recovery was comparable to acidic water and hot water at [60C°]. Fractionation of the extract from the aerial part of Argemone mexicana led to the isolation of 3 major alkaloids which were identified using preparative TLC, IR spectroscopy, HPLC, GC- MS and literature reports as berberine, protopine and benzophenathridine. The seed isolated compound contains Dihydrosanguinarine as a major alkaloid.

Keywords: Argemone mexicana, extraction, identification