Droplet Counter-Current Chromatography and its Application to the Preparative Scale Separation of Natural Products

Droplet counter-current chromatography (DCCC) is a recently developed all-liquid separation technique based on the partitioning of solutes between a steady stream of droplets of mobile phase and a column of surrounding stationary phase [1]. It is particularly indicated for the preparative scale separation of polar compounds and has been applied to the isolation of various types of natural products. In many cases, the separations were achieved far more readily than by conventional chromatography and with a smaller solvent consumption. In the present paper, the principle of DCCC is described and a quick method based on thin-layer chromatography (TLC) for the selection of the solvent system is proposed. An up to date literature survey is given and the problems specific to the different classes of compounds are discussed. Advantages and limits of DCCC, as well as its position among the various available methods for the preparative scale separation, are discussed. Key Word Index Droplet Counter-Current Chromatography - Natural Products Isolation - Saponins - Polyphenols - Iridoid Glycosides - Cardenolides - Alkaloids - Peptides - Lipids - Monosaccharides - Cvclitols.