Novel cytotoxic 1H-cyclopenta[b]bezofuran lignans from Aglaia elliptica - Cui,B.; Chai,H.; Santisuk,T.; Reutrakul,V.; Fansworth,N.R.; Cordell,G.A.; Pezzuto,J.M.; Kinghorn,A.D. (Tetrahedron, 1997)