Triterpenes and antimicrobial activity evaluation of Cladogelonium madagascariense Leandri (Euphorbiaceae)

Background: Cladogelonium madagascariense Leandri is a single genus, single species endemic plant of Madagascar. The aerial parts are used to treat the fevers with grippe symptoms and neurological signs by steam bath. The aim of this study was to evaluate its antimicrobial activity, isolate and identify its phytochemical constituents. Methods: The aerial parts of the plant were collected, shade-dried, and pulverized into a fine powder. Preliminary phytochemical screening of the crude ethanol extract was conducted using standard qualitative methods. The antimicrobial activity was evaluated using the disk-diffusion method with the ethanolic extract. Sequential extraction of aerial parts powder was performed by maceration using solvents of increasing polarity: hexane, ethyl acetate, and methanol. Chromatographic separation of the extracts was performed, and compounds isolated from the hexane extract were identified using nuclear magnetic resonance (NMR) spectroscopy and by comparison with literature data. Results: The screening phytochemical analysis of Cladogelonium madagascariense Leandri revealed the presence of flavonols, leucoanthocyanins, triterpenes, steroids, unsaturated sterols, tannins, and saponins in ethanolic extract. Antibacterial study of this species revealed that was active against the six Gram-positive and Gram-negative bacteria: Bacillus cereus, Bacillus megaterium, Listeria monocytogenes, Enterobacter cloacae, Salmonella enteritidis and Streptococcus pneumoniae using disc diffusion method at the concentration of 2 mg/disc. Fractionation of the hexane extract led to the isolation of five known triterpenes: lupeol (1); glut-5-en-3α-ol (2); friedelin (3); alstrinine (4) and hederagenin (5). Conclusion: These findings demonstrate the presence of tetracyclic triterpenes in the hexane and ethyl acetate extracts of Cladogelonium madagascariense aerial parts. The ethanol extract exhibit antimicrobial activity. These results highlight the potential of this plant for use in phytomedicine.