Euphormins A and B, New Pyranocoumarin Derivatives from Euphorbia formosana Hayata, and Their Anti-Inflammatory Activity.

Euphormin-A ( 1 ) and euphormin-B ( 2 ), two new pyranocoumarin derivatives, and forty known compounds ( 3 - 42 ) were isolated from Euphorbia formosana Hayata (Euphorbiaceae). The chemical structures of all compounds were established based on spectroscopic analyses. Several isolates were evaluated for their anti-inflammatory activity. Compounds 1 , 2 , 10 , 18 , 25 , and 33 significantly inhibited against superoxide anion generation and elastase release by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). Furthermore, compounds 25 and 33 displayed the most potent effects with IC 50 values of 0.68 ± 0.18 and 1.39 ± 0.12 µM, respectively, against superoxide anion generation when compared with the positive control (2.01 ± 0.06 µM).