3 NEW ADJACENT BIS-TETRAHYDROFURAN ACETOGENINS WITH 4 HYDROXYL-GROUPSFROM ASIMINA-TRILOBA

Three new adjacent bis-tetrahydrofuran ring Annonaceous acetogenins wi th four hydroxy groups, bullatetrocin (1), 10-hydroxyasimicin (2), and 10-hydroxytrilobacin (3), were isolated by activity-directed fraction ation from the stem bark of Asimina triloba. Their structures were est ablished on the basis of chemical and spectral evidence. The absolute stereochemistry at the C-10 hydroxy position was determined by convert ing 2 and 3 to their ketolactone isomers, 2,4-cis/trans 10-hydroxyasim icinones and 2,4-cis/trans 10-hydroxytrilobacinones, respectively. The bioactivities of the new compounds against brine shrimp larvae and si x human solid-tumor cell lines are reported, and structure-activity re lationships between trihydroxylated and tetrahydroxylated acetogenins are discussed. In addition to 1-3, gigantetrocin A, 2,4-cis/trans-giga ntetrocin A-ones, annonacin, and annonacin A were also isolated for th e first time from this species.