Analgesic sesquiterpene dilactone from Mikania cordata

The crude extract of Mikania cordata (1 and 3 g/kg, p.o.) and deoxymikanolide (1) (10 mg/kg, p.o.) significantly inhibited acetic acid-induced writhing in mice. Three other sesquiterpene dilactones isolated from the same plant, namely mikanolide, dihydromikanolide and scandenolide, did not show significant analgesic activity.