A new ferulic acid ester, a new ellagic acid derivative, and other constituents from Pachycentria formosana: Effects on neutrophil pro-inflammatory responses

A new ferulic acid ester derivative, tetracosane-1,24-diyl di[(Z)-ferulate] (1), and a new ellagic acid derivative, 3,4:3′,4′-bis(O,O- methylene)ellagic acid (2), have been isolated from leaves and twigs of Pachycentria formosana, together with eight known compounds. Their structures were determined by in-depth spectroscopic and mass-spectrometric analyses. Among the isolated compounds, oleanolic acid (6), ursolic acid acetate (7), and 3-epibetulinic acid (9) exhibited potent inhibition (IC ₅₀ values ≤21.8μM) of O ₂ ^·- generation by human neutrophils in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine/ cytochalasin B (fMLP/CB). In addition, oleanolic acid (6), 3-O-[(E)-feruloyl] ursolic acid (8), 3-epibetulinic acid (9), and lawsonic acid (10) also inhibited fMLP/CB-induced elastase release with IC ₅₀ values ≤ 18.6μM.