Four new modified eremophilanes, together with ten known cacalol derivatives, two caryophyllenes, one aromadendrene and one flavonoid were isolated from Psacalium cirsiifolium. The structures of these compounds were elucidated by spectroscopic analysis. The anti-inflammatory activity of extracts and of seven of the isolated compounds was evaluated on 12-O-tetradecanoylphorbol-13-acetate (TPA) model of induced acute inflammation. The new compound 2α -hydroxyadenostin B (4) showed a dose dependent activity (IC50 0.41 µmol per ear) and a neutrophil inhibition effect as measured by the myeloperoxidase (MPO) assay similar to that of indomethacin at 0.31 and 1.0 µmol per ear.
Psacalium; modified eremophilanes; anti-inflammatory activity; TPA; myeloperoxidase