Volatilome and Antinociceptive Activity of the Traditional Preparation and Compounds from Ageratina grandifolia (Regel) R.M. King & H. Rob.

Abstract An infusion of Ageratina grandifolia, a traditional preparation, and major compounds [3,5‐diprenyl‐4‐hydroxyacetophenone (1), O‐methylencecalinol (2), encecalin (3), and encecalinol (4)], tested at 10, 31.6, and 100 mg/kg, intragastrically administered, showed a significant antinociceptive effect in both phases of the formalin test in mice. Encecalinol (4) was the most active and showed a dose‐dependent antinociceptive action in both phases; its effect was substantially attenuated when the mice were pretreated with naloxone. The volatile constituents of A. grandifolia, A. petiolaris, and