Estrogenic and serotonergic butenolides from the leaves of Piper hispidum Swingle (Piperaceae) - Michel, J L; Chen, Y; Zhang, H; Huang, Y; Krunic, A; Orjala, J; Veliz, M; Soni, K K; Soejarto, D D; Caceres, A; Perez, A; Mahady, G B (J Ethnopharmacol, 2010)