Study of the Antinociceptive Action of the Ethanolic Extract and the Triterpene 24-Hydroxytormentic Acid Isolated from the Stem Bark of Ocotea suaveolens - Beirith, Alessandra; Santos, Adair R S; Calixto, João B; Hess, Sônia C; Messana, Irene; Ferrari, Franco; Yunes, Rosendo A (Planta Medica, 1999)