Cation-exchange micropreparative separation of galloylated and non-galloylated sulphur conjugated catechins

Catechin conjugates bearing an amino function can be separated from underivatized monomers by cation-exchange chromatography. Here, chromatographic conditions for the separation of epicatechin gallate-containing conjugates from the non-galloylated conjugates at micropreparative scale are described. The separation was achieved by exploiting either the hydrophobic or hydrophilic interactions of the conjugates with the core polymer. The retention was modulated by changing the amount of organic co-solvents (MeOH, EtOH, CH3CH, THF) in the elution buffers. The best resolution compatible with small peak widths was obtained at 20-30% EtOH. The experiments were reproducible.