Phytochemical and biological activities of Bituminaria bituminosa L. (Fabaceae).

Objective: To investigate the phytochemical composition, the antioxidant and antibacterial activities of Bituminaria bituminosa L. (Fabaceae) (B. bituminosa).

Methods: The aerial parts of B. bituminosa yielded two compounds. The structures of these compounds were determinated using UV, (1)H-NMR and (13)C-NMR experiments and comparison of their spectroscopic properties with literature data. The antibacterial activity of the extracts (CH2Cl2, ethyl acetate and n-BuOH) was determinated using disk diffusion method against standard and clinical strains. Antioxidant potential of n-BuOH extract was evaluated through two methods: DPPH and cupric ion reducing antioxidant capacity assay.

Results: The n-BuOH extract from B. bituminosa yielded the isolation of isoflavone and flavone. The extracts CH2Cl2, ethyl acetate and n-BuOH demonstrated significant antibacterial activities. CH2Cl2 extract showed the maximum antibacterial activity with high concentration of 2 mg/mL against Staphylococcus aureus ATCC 29213, Klebsiella pneumonia and Escherichia coli ATCC 25922 (20.45 mm, 16.41 mm and 15.74 mm inhibition zone, respectively). The value IC50 was 0.26 μg/mL for n-BuOH extract using DPPH method. Whereas the E% value was 0.10 L/mg every centimeter for cupric ion reducing antioxidant capacity assay.

Conclusions: The phytochemical study of B. bituminosa revealed the presence of isoflavone (daidzin) and flavone (isoorientin) and identified for the first time in this specie. The antibacterial activity of the plant B. bituminosa is certainly related to its chemical content. The n-BuOH extract showed a significant antioxidant activity.