A simple, inexpensive, and efficient method for separation and purification of the alpha- and beta- FORMS OF penta-O-galloyl-D-glucose (PGG) without the need for HPLC. The methods provided herein are useful for separating alpha-PGG or beta-PGG from a mixture that contains alpha-PGG and beta-PGG and other chemicals. The method for separation of alpha-PGG from a mixture of alpha-PGG and beta-PGG comprises the steps of: adding water to a sample containing 50% or more alpha-PGG and 50% or less beta-PGG; mixing the PGG and water to dissolve the PGG; filtering out any undissolved particles; and allowing the filtered solution to stand undisturbed until crystals form. |