Desacetylmatricarin, an anti-allergic component from Taraxacum platycarpum

The bioassay-guided fractionation of Taraxacum platycarpum (Compositae) extract led to the isolation of a desacetyl-matricarin (1) as an active principle responsible for the anti-allergic property. It showed a potent inhibitory activity upon the beta-hexosaminidase release from RBL-2H3 cells in a dose-dependent manner and the IC50 was 7.5 mu M. Two structurally related guaianolide sesquiterpenes, achillin and leucodin, were also examined and their IC50 values were determined as 100 mu M and 80 mu M, respectively.