Two-dimensional thin-layer chromatography of selected Polygonum sp. extracts on polar-bonded stationary phases.

Two-dimensional thin-layer chromatographic systems on cyano-bonded polar stationary phases were used for the separation of some phenolic compounds extracted from two species of Polygonum: Polygonum hydropiper L. and Polygonum cuspidatum L. Non-aqueous solvents were used in the first direction and aqueous solvents were used in the second direction on CN silica TLC plates. For the separation of phenolics' standards optimal chromatographic systems were chosen from the retention data collected in one-dimensional TLC experiments by plotting graphs of R(F) vs. R(F) dependencies. Using above described method the satisfactory results of separations were obtained.