BULLATIN AND BULLANIN - 2 NOVEL, HIGHLY CYTOTOXIC ACETOGENINS FROM ASIMINA-TRILOBA

Two new highly cytotoxic adjacent bis-tetrahydrofuran acetogenins, bul latin (2) (10-hydroxy-4-deoxybullatacin) and bullanin (5) (30-hydroxy- 4-deoxybullatacin), have been isolated from the ethanolic extract of t he stem bark of Asimina triloba by directing the fractionation with br ine shrimp lethality. In addition to these two new compounds, two prev iously reported acetogenins, squamocin (3) (28-hydroxy-4-deoxybullatac in) and motrilin (4) (29-hydroxy-4-deoxybullatacin) which are new to t his species, were obtained. Through spectral analysis these four aceto genins were structurally identified as hydroxylation isomers of bullat acin (1) which was recently patented as an antitumor agent. All of the se acetogenins showed high potencies in the brine shrimp test (BST) an d in cytotoxicity tests against human solid tumor cell lines in cultur e, with certain potencies quite comparable to those of bullatacin (1) and several orders of magnitude greater than those of adriamycin.