Acridone alkaloids from Vepris verdoorniana (Excell & Mendonça) Mziray (Rutaceae).

Two new acridone alkaloids, verdoocridone A ( 1 ) and B ( 4 ), together with fifteen known compounds were isolated from methanol extracts of the roots and leaves of Vepris verdoorniana . The structures of all compounds were determined by comprehensive spectroscopic analyses (1D and 2D NMR, EI- and ESI–MS). The 13 C NMR values of 1,2,3,5-tetramethoxy- N -methylacridone ( 2 ) and 5-methoxyaborinine ( 3 ) are also reported. The crude extracts and compounds ( 1 - 6 ) were tested for their antimicrobial activity. The test delivered moderate activities for crude extracts and compounds 1 , 5 and 6 against the bacterium Staphylococcus aureus and the fungi Mucor meihei and Candida albicans with MIC values between 115 and 180 μg/mL for extracts and between 21.3 and 29.4 μM for compounds, compared to gentamycin with 0.2 μM and nystatin with 5.2 μM against both fungi. The determination of the radical scanvenging activity using 1,1-dephenyl-2-picrylhydrazyl (DPPH) assay gave moderate antioxidant values for all tested compounds, with IC 50 between 0.29 and 0.41 μM, compared to the standard 3-t-butyl-4-hydroxyanisole (BHA) displaying 0.03 μM. [ABSTRACT FROM AUTHOR]