Campesterol semi-synthetic derivatives as potential antibacterial: In vitro and in silico evaluation.

In this study, twelve campesterol derivatives (2-13) were prepared by structural modification at the hydroxyl group in C-3 and catalytic hydrogenation at the carbon-carbon double bond in C-5(6). All obtained compounds were characterized by infrared (IR), nuclear magnetic resonance (1H and 13C-NMR) and mass spectrometry (MS). Campesterol (1) and all campesterol derivatives (2-13) were evaluated against Staphylococcus aureus (ATCC 6538), Streptococcus mutans (ATCC 0046), Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 15442), and Klebsiella pneumoniae (ATCC 10031). Among tested compounds, 4, 6, 9, 11, 12, and 13 displayed the best antibacterial activity. Moreover, to support the antibacterial activity experiments, the investigation of molecular interactions of more active compounds, and also compound 1 and neomycin, used as starting material and positive control, respectively, at the binding site of the target proteins was performed using molecular docking simulations. Four compounds (7, 9, 10 and 11) are herein described for the first time.