Two-Dimensional Thin-Layer Chromatography of Structural Analogs. Part II. Method for Quantitative Analysis of Selected Coumarins in Plant Material

Coumarins are interesting group of natural compounds, because of their biological and pharmacological activity, and are widely investigated. They are normally found in complex mixtures, e.g. plant extracts, and are difficult to separate in one chromatographic run. Mixtures of coumarins have been separated by two-dimensional thin-layer chromatography on CN-silica plates by use of aqueous and nonaqueous mobile phases. Complete separation was also achieved by use of graft thin-layer chromatography on connected layers — silica with RP-18W or CN-silica with silica. The systems characterized by the best efficiency and selectivity were used for separation of coumarin fractions from extracts of selected Apiaceae plants. These orthogonal systems were used for quantitative analysis of selected coumarins. The results obtained show two dimensional thin-layer chromatography is useful tool for quantification of some furanocoumarins in plant extracts. The best results were obtained on connected silica and octadecyl silica layers.