Desacetylmatricarin, an Anti-Allergic Component fromTaraxacum platycarpum

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