Antibacterial activity of naringenin-rich fraction of pigeon pea leaves toward Salmonella thypi

Objective: To identify bioactive compound in pigeon pea leaves (Cajanus cajan) that inhibits Salmonella thypi (S. thypi). Methods: The leaf sample was powdered and macerated with methanol and fractioned by liquid-liquid extraction using ethyl acetate. The fraction was chromatographed and the isolates were identified for major component with liquid chromatography-mass spectrometry and the antibacterial activity was tested against S. thypi by Kirby-Bauer method. Results: Subfraction 1 from the ethyl acetate fraction formed a yellowish solid with m/z 272, identified as naringenin. The naringenin-rich fraction shows fairly well inhibitory toward S. thypi in comparison with chloramphenicol. Conclusions: Naringenin shows antibacterial activity and can be developed to treat typhoid.