Gradient thin-layer chromatography of extracts fromDigitalis lanata andDigitalis purpurea

Summary Glycosides isolated fromDigitalis lanata andDigitalis purpurea (1985–1991 crops) were chromatographed on High-Performance precoated silica layers using stepwise gradient elution, the eluents containing increasing concentrations of methanol in ethyl acetate. The extracts were separated into about 20 components, presumably glycosides, some of which were identified using a mixture of standards. Densitograms at 365 nm were also obtained. The adsorbent-eluent system was very efficient and the separation was rapid owing to the use of a non-aqueous mobile phase. The method is suitable for the comparative analysis of lanatosides in plant extracts.