Effect of Digitalis lanata matrix composition on the lanatoside C partition coefficient and its consequence on rotation locular countercurrent chromatography efficiency

Lanatoside C standard samples had their partition coefficients (K) determined in dichloromethane-methanol-water (4:4:3), (5:6:4) and (7:13:8), by the shake flask method and the obtained values were similar. On the other hand, K for lanatoside C accomplished by calculation from rotation locular counter-current chromatography (RLCC) traces of Digitalis lanata pre-purified extracts, as well as by the shake flask method, in the same solvent systems, showed a significant variation. Such variation was attributed to differences in the pre-purification procedures for D. lanata extract, which resulted in starting materials for RLCC with very distinct cardenolide profiles, reflecting, thus, in the K values for lanatoside C and, consequently, in the lanatoside C purity at the end of the chromatographic process. (C) 1998 Elsevier Science B.V. All rights reserved.