ISOLATION OF BIOACTIVE AND OTHER OXOAPORPHINE ALKALOIDS FROM 2 ANNONACEOUS PLANTS, XYLOPIA-AETHIOPICA AND MILIUSA CF BANACEA

The oxoaporphine alkaloids oxophoebine [1) and liriodenine [2] have been isolated from Xylopia aethiopica (Annonaceae). Both showed selective toxicity against DNA repair and recombination deficient mutants of the yeast Saccharomyces cerevisiae. Three related but inactive compounds, oxoglaucine [3], O-methylmoschatoline [4], and lysicamine [5], were also isolated from this plant. Selective toxicity was also observed for 10-methoxyliriodenine (lauterine) [6] and 10-hydroxyliriodenine [7], two oxoaporphine alkaloids isolated from Miliusa cf. banacea (Annonaceae). The structure of 10-hydroxylitiodenine [7], a novel oxoaporphine, was determined by spectroscopic methods and chemical conversion to compound 6. The role of the bioactive oxoaporphine alkaloids as DNA topoisomerase inhibitors is discussed.