Process for the extraction and purification of cesalin

Pure cesalin having a high degree of anti-tumor activity is obtained by organic solvent extraction of either the whole seeds or the endosperm of the plant Caesalpinia gilliesii, to remove a lipid portion, extraction of the defatted endosperm with water, dialysis of the extract against water, separation of the non-dialyzable portion into a supernatant, precipitating crude cesalin from the supernatant by acidification or with ammonium sulfate, and purifying the crude cesalin by gel filtration and elution.