Phytoconstituents with Radical Scavenging and Cytotoxic Activities from .

As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of (Ebenaceae), a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8'-oxo-biplumbagin () was isolated along with the known tetralones -isoshinanolone () and -isoshinanolone (), and the naphthoquinones plumbagin () and 3,3'-biplumbagin (). Compounds , , and showed cytotoxicity (IC 520-82.1 μM) against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC 16.1, 29.7 and > 100 μg/mL, respectively), and for the methanol extract of the stem bark (IC 59.6 μg/mL). The radical scavenging activity of the isolated constituents (-) was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.