Hexanic seed extracts from Amburana cearensis and Persea americana: a in vitro approach to citrus canker control

Abstract: Citrus canker is caused by the phytopathogenic bacterium Xanthomonas citri subsp. citri. Conventional control strategies rely heavily on copper-based bactericides, which pose environmental and resistance-related concerns. In this study, we propose a green alternative using hexanic seed extracts from Amburana cearensis(HE-AC) and Persea americana (HE-PA) to inhibit X. citri growth. Chemical profiling by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection revealed coumarin (25.0%) as the major volatile in HE-AC, while HE-PA contained high levels of linalool (26.0%). Antibacterial activity was evaluated using the broth microdilution method in 96-well plates, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values expressed in µg/mL. HE-AC exhibited good antibacterial effects, with MIC and MBC values of 50 µg/mL. Similarly, HE-PA demonstrated promising results, with MIC and MBC values of 62.5 µg/mL. It is worth noting that the MBC/MIC ratio of < 4 confirms the bactericidal effect of both extracts. In the molecular docking study, coumarin displayed superior binding performance compared to linalool, with stronger binding energy, higher ligand efficiency, and a more diverse interaction profile, including multiple hydrogen bonds and p–p stacking. These findings suggest that coumarin may serve as a more effective ligand for modulating the target protein. These findings highlight the potential of seed-derived hexanic extracts, especially HE-AC, as effective and eco-friendly agents against X. citri (in vitro).