CYTOTOXIC FALCARINOL OXYLIPINS FROM DENDROPANAX-ARBOREUS

The crude organic extract of Dendropanax arboreus was selected as a ca ndidate for bioassay-guided fractionation on the basis of its relative ly selective cytotoxicity to a subset of cell lines within the Nationa l Cancer Institute's disease-oriented in vitro tumor-screening panel. The major compound responsible for the in vitro cytotoxicity was falca rinol (1). Several other known compounds were isolated and found to be cytotoxic, including dehydrofalcarinol (2), a diynene (3), falcarindi ol (4), and dehydrofalcarindiol (5). In addition, two novel polyacetyl enes, dendroarboreols A (6) and B (7), were isolated and characterized by standard and inverse-detected NMR methods. Compounds were selected from this series for absolute stereochemical determination using the modified Mosher method and preliminary in vivo evaluation using a LOX melanoma mouse xenograft model.