Abstract
Micellar electrokinetic capillary chromatography (MECC), using a phosphate buffer
pH 7.0 and sodium dodecyl sulfate as the surfactant, was found suitable for the separation
of structurally similar flavan-3-ols and related dimeric proanthocyanidins. A total
of 20 substances has been tested, 17 of which were successfully separated simultaneously
in less than 7 minutes. Retention of the investigated compounds by the SDS micelles
is affected by (i) the stereochemistry of the heterocycle of the flavan-3-ol skeleton,
(ii) the molecular size, the number and position of free phenolic hydroxy groups,
and (iii) the type of acyl residues attached at the C-3 hydroxy function. The method
was successfully applied to the phytochemical analysis of tannin enriched extracts
of Cistus incanus L. ssp. incanus and C. salvifolius L. (Cistaceae), two traditionally used medicinal plants.
Key words
Capillary electrophoresis - CE - MECC - proanthocyanidins - flavan-3-ols -
Cistus incanus L. -
Cistus salvifolius L. -
Cistaceae
