A new limonoid, digsecokigelianolide, among the secondary metabolites from <i>kigelia africana</i> (lam.) benth. and evaluation of their antibacterial and antioxidant activity

The present work investigates the phytochemical study and the antibacterial and antioxidant activities of <i>Kigelia africana</i> (Lam.) Benth. Column chromatography separation on silica gel of fractions led to the isolation of a new limonoid derivative named digsecokigelianolide (<b>1</b>), as well as nine known compounds (<b>2-10</b>). The structures of the isolated compounds were determined by comprehensive spectroscopic analysis, including 1 & 2D NMR, IR, UV, mass spectrometry and comparison with previous reported data. Compound <b>1</b> showed moderate antiradical activity (IC₅₀ = 181.12 µg/mL) against ABST^•+ radical compared to BHT (159.48 µg/mL) used as standard, and a good antibacterial activity against <i>Salmonella typhi</i> (MIC: 22.0 mm), <i>Escherichia coli</i> (MIC: 15.0 mm) and <i>Pseudomonas aeruginosa</i> (MIC: 20 mm) at the concentration of 25 mg/mL. Compound 9 and 10 showed good antiradical (which ranges from 56.39 to 61.16% of inhibition) and antibacterial (which ranges from 12 to 20 mm of inhibition zone) activities.