Methoxylated bibenzyls and isoflavones from Baphia massaiensis Taub.

Chemical investigation of the stem bark of Baphia massaiensis Taub. led to the isolation of two new natural compounds named 3-hydroxy-2,5,2′-trimethoxybibenzyl (1) and 2′-hydroxy-2,3,5,6-tetramethoxybibenzyl (2), the latter has been previously reported as a synthetic compound, together with twelve known compounds 3–14. The chemical structures of the isolated compounds were elucidated by using NMR analysis and mass spectrometry, as well as comparisons with the reported data in the literature. Known bibenzyls 3–5, bauhinoxepin J (6), and isoflavones 7–10 and 12–14, were reported from genus Baphia for the first time. The isolated compounds were evaluated for their antibacterial activities in-vitro against Staphylococcus aureus and Escherichia coli. The bioactivity evaluation revealed that bibenzyls 1 and 2 showed weak inhibitory activity with MIC values of 1000 µg/mL against S. aureus and bauhinoxepin J (6) showed moderate inhibitory activity with MIC value of 63 µg/mL against S. aureus. [ABSTRACT FROM AUTHOR]