Analysis of glycosides and aglycones of flavonoid compounds by double-development thin-layer chromatography

Abstract

Flavonoid glycosides are much more polar than their aglycones and the two groups of compounds are difficult to separate by planar chromatography owing to the ‘general elution problem’ — glycosides require development with mobile phases of higher eluent strength. The problem of separating both groups can be solved by gradient elution or by incremental gradient multiple development in its simplest form — double development. The latter technique is illustrated for nine glycosides and seven aglycones by development along two-thirds of the plate length with a strong mobile phase and, after evaporation of the solvent, development to the full distance with a weaker mobile phase. The two stages of development are illustrated by densitograms.