The invention relates to extraction concentration and separation of fractions containing Bacosides A and B from plant materials of Bacopa species. The dried plant materials are subjected to alcoholic or hydroalcoholic or water extraction and concentration of the extract. This solid mass is washed with a nonpolar organic solvent to remove fatty materials therefrom. The solid obtained thereafter is extracted with an organic polar solvent, the solvent extract is washed with water to remove water soluble contaminants therefrom and then dried in vacuum. This factor which is enriched with Bacosides A and B is subjected repeated chromatographic separation and purification to obtain Bacoside A and Bacoside B therefrom.