Cytotoxic constituents of the roots of Ekmanianthe longiflora - Peraza-Sanchez, S R; Chavez, D; Chai, H B; Shin, Y G; Garcia, R; Mejia, M; Fairchild, C R; Lane, K E; Menendez, A T; Farnsworth, N R; Cordell, G A; Pezzuto, J M; Kinghorn, A D (J Nat Prod, 2000)