Antibacterial and cytotoxic biflavonoids from the root bark of Ochna kirkii

The new isoflavonoid kirkinone A (1) and biflavonoid B (2) along with six known compounds (3–8) were isolated from the methanolic extract of root bark Ochna kirkii. identified by NMR spectroscopic mass spectrometric analyses. Out eight natural products, calodenin (4) lophirone (6) showed significant antibacterial activity against Gram-positive bacterium Bacillus subtilis MIC values 2.2 28 μM, cytotoxicity MCF-7 human breast cancer cell line EC50 219.3 19.2 respectively. crude exhibited at 8.4 μg/mL. secondary metabolites generally inactive Gram-negative Escherichia coli (MIC ≥400 μg/mL). Isolation biflavonoids related O. kirkii demonstrates their chemotaxonomic significance to genus other members family Ochnaceae.