Flavonoids with antimicrobial activity from the stem bark of Commiphora pedunculata (Kotschy & Peyr.) Engl

The first reported investigation into the phytochemical constituents of Commiphora pedunculata led to the isolation of two flavonoids: kaempferol and dihydrokaempferol from the ethyl acetate-soluble fraction of the methanol extract of the stem bark of the plant. The structures of these compounds were characterised by comparing their spectral data including 1D and 2D NMR with those reported in the literature. The two compounds were active against 6 out of 10 tested microorganisms including two resistant strains [methiciline-resistant Staphylococcus aureus and vancomycin-resistant entrococci (VRE)], Candida albicans and Escherichia coli. The zones of inhibition ranged between 24 and 30 mm for both compounds against the microorganisms. The MIC value was as low as 6.25 μg/mL against VRE and Staphylococcus aureus. This is the first report of the isolation of these compounds from the plant.