An Improved Method for The Isolation of the Lignan Constituents of <i>Saururus Cernuus</i> by Reverse Phase Column Chromatography

Abstract

Abstract The above-ground parts of the aquatic weed, Saururus cernuus contain many constituents with varying and significant biological acitivities. In the earlier method of isolation, the concentrated methanolic extract was fractionated by a 2–3 step solvent partition, and the appropriate fractions subjected to two or three steps of chromatography, as well as other manipulations, which together, made the isolation a somewhat elaborate and time-consuming operation, especially when a medium to large-scale extraction is to be carried out. In an effort to simplify this process, the methanolic extract concentrate is now partitioned between benzene and water, and the organic extract subjected directly to reverse phase column chromatography. Most of the lignan constituents could be isolated either directly, or after one small additional column, where necessary. This method has some distinct advantages over the earlier scheme. Besides being simpler, and more readily applicable for large-scale work-up, the chlorophylls and other liipophilic components, which usually contaminate the lignan fractions in the normal phase silica column, remain on the column until almost all of the lignan constituents are eluted, thus aiding the purification. The previously obtained lignan components, can all be isolated readily by the use of this simplified procedure.