5-(4-Hydroxyphenethenyl)-4,7-dimethoxycoumarin, a new constituent of Monotes engleri - Seo,E.-K.; Chai,H.B.; Chagwedera,T.E.; Farnsworth,N.R.; Cordell,G.A.; Pezzuto,J.M.; Kinghorn,A.D. (Planta Med., 2000)