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Abstract
The separation of free and glycosylated flavonoids from the ethyl acetate extract of the leaves of Siparuna guianensis by step‐gradient and isocratic mode HSCCC is described. The initial fractionation of the extract by a two‐step gradient composed of Hexane∶EtOAc∶MeOH∶H2O 0.6∶4.0∶0.05∶1.0 v/v/v/v (A) and 0.6∶4.0∶0.7∶1.0 (B), reverse phase HSCCC, yielded a sequence of a mixture of diglycosyl flavonoids, followed by a mono‐glycosyl flavonoid and by quercetin, a free flavonoid. The final separation of the more polar and very closely related (structurally and chemically) glycosylated flavonoids, not easily separable by HPLC, was achieved by isocratic normal phase elution, with the solvent system Hexane∶EtOAc∶BuOH∶MeOH∶H2O, 0.6∶4.0∶1.0∶0.05∶1.0. The optimization of the solvent ratios for the gradient and for the isocratic elution is discussed.
Acknowledgments
G. G. Leitão is especially indebted to CNPq and FAPERJ for financial support and the opportunity of presenting this paper at the 3rd International Countercurrent Chromatography Conference (CCC2004) at Tokyo, Japan, 2004.
