Antimicrobial activities of the CH2Cl2–CH3OH (1 : 1) extracts and compounds from the roots and fruits of Pycnanthus angolensis (Myristicaceae)

This study was designed at evaluating the antimycobacterial, antibacterial and antifungal activities of the CH2Cl2–CH3OH (1 : 1) extracts and isolated compounds, namely 3,4-dimethoxy-3′,4′-methylenedioxy-7,7′-epoxylignan (1), genkwainin (2), pycnanthulignene C (3), 4,5-dimethoxy-3′,4′-methylenedioxy-2,7′-cycloligna-7,7′-diene (4), pycnanthulignene A (5) from the roots, and calycosin (6), biochanin A (7) and prunetin (8), from the fruits of Pycnanthus angolensis. The microplate alamar blue assay and the broth microdilution method were used to determine the minimal inhibitory concentration (MIC) and minimal microbicidal concentration of the samples. The H+-ATPase-mediated proton pumping assay was used to evaluate one of the possible mechanisms of action of the extracts and isolated compounds. The results of MIC determinations showed that the extract from roots was able to prevent the growth of all the studied organisms, including mycobacteria, fungi, and Gram-positive and Gram-negative bacteria. All tested ...