ADDITIONAL BIOACTIVE ANNONACEOUS ACETOGENINS FROM ASIMINA-TRILOBA (ANNONACEAE)

Trilobalicin (1), a new nonadjacent bis-THF ring annonaceous acetogeni n, 2,4-cis- (2) and 2,4-trans-trilobacinone (3), the ketolactones of t rilobacin, an adjacent bis-THF ring acetogenin, were isolated from the stem bark of Asimina triloba (L.) Dunal (Annonaceae). Their structure s were established based on chemical and spectral evidence. The relati ve stereochemistry of 1 was determined as trans/threo/threo/trans/eryt hro from C-10 to C-22 by comparisons of NMR data with those of model c ompounds. Compound 1 is the first example of a nonadjacent bis-THF ace togenin being isolated from the title species and represents a new typ e of these compounds. Bioactivities of these new structures against br ine shrimp larvae and six human solid tumor cell lines were determined , and cytotoxic selectivities were shown for the lung (A-549) and brea st (MCF-7) cell lines with up to a million times the potency of adriam ycin. (C) 1997 Elsevier Science Ltd.