Chemical constituents with anti-allergic activity from the root of Edulis Superba, a horticultural cultivar of Paeonia lactiflora

The methanolic extract and its subfractions from the dried root of Edulis Superba, a horticultural cultivar of Paeonia lactiflora Pallas, showed potent anti-allergic effect as inhibition of immunoglobulin E (IgE)-mediated degranulation in rat basophil leukemia (RBL)-2H3 cells. Bioassay-guided fractionation led to the isolation of 26 compounds, including a new norneolignan glycoside, paeonibenzofuran (1), together with 25 known ones (2-26). The chemical structure of the new compound was elucidated on the basis of spectroscopic and chemical evidences. Among the isolated compounds, mudanpioside E (5) with paeoniflorin-type skeleton and quercetin (16) showed potent inhibitory activity against a degranulation marker, β-hexosaminidase release with IC₅₀ values of 40.34 and 25.05 μM, respectively. A primary structure-activity relationship of these components was discussed.