Résumé: The addition of a furan moiety to methylphosphonate can lead to molecules possessing strongest antibacterial and antifungal properties. In this work, novel furan α-acetoxy methylphosphonate derivatives were designed and successfully synthesized in two steps using α-hydroxyphosphonates as intermediates. The desired products were obtained with excellent yields (up to 80 %), and their chemical structures were confirmed by IR, UV–vis, NMR (1H, 13C, 31P), as well as HRMS analyses. The antibacterial and antifungal activities of these molecules were assessed against ten Gram-negative bacteria, such as Escherichia coli (ATCC 25,922, ertapenem-resistant, and ciprofloxacin-resistant strains), Klebsiella pneumoniae (KPC), Pseudomonas aeruginosa (ATCC 27,853, VIM-2-producing, and imipenem-resistant strains), and Acinetobacter baumannii (ESBL, OXA-23, and carbapenemase-producing strains); four Gram-positive bacteria, including Staphylococcus aureus (ATCC 25,923, 29,213, and ATCC 43,300) and Bacillus cereus; and two fungi, including Candida albicans and Saccharomyces cerevisiae. The results showed that all compounds exhibited high antibacterial and antifungal activities. DFT calculations were carried out using the CAM-B3LYP/6–31 G (d,p) basis set to study the stability and reactivity of the compounds through the HOMO and LUMO energy values. Additionally, topology analyses (ELF, LOL, and RDG) were performed using Multiwfn software to further elucidate the reactivity of the molecules. Molecular docking studies revealed strong interactions between the synthesized compounds and target proteins. Overall, the results demonstrate the promising antibacterial and antifungal potential of the studied compounds.

Résumé: Four 4-phenyldiazenyl phenyl aminophosphonates were successfully synthesized using an eco-friendly one-pot Kabachnik-Fields reaction. The reaction involved aromatic aldehydes, 4-(Phenyldiazenyl) aniline, and diethylphosphite, with Ni(SO4).6H2O (5 mol%) serving as an efficient catalyst. Conducted at room temperature under solvent-free conditions within 20 min, the reaction yielded excellent chemical results, with up to 90 % yields. The compounds underwent characterization through IR, UV-vis, NMR (1H, 13C, 31P), and HRMS. The antibacterial activity of the synthesized molecules was evaluated against two Gram-negative bacteria (Escherichia coli ATTC 25922, Pseudomonas aeruginosa ATTC 27853) and the Gram-positive bacterium (Staphylococcus aureus ATTC 25923) at different compound concentrations (32-128 µg/ml) compared to Cefixime. The results revealed significant antibacterial activity of molecules 4b, 4c and 4d against the two Gram-negative bacteria and 4b against S. aureus, with a minimum inhibitory concentration (MIC) of 0.5 µg/mL, surpassing the reference drug. DFT calculations at B3LYP 6-311G (2d, p) basis set were employed for geometry optimization, stability and reactivity studies, including HOMO/LUMO, ΔEGAP, dipole moment, electronegativity, electrophilicity, and calculated thermodynamic descriptors (Enthalpy and Gibbs Free Energy). The molecular docking studies confirmed strong interactions between the synthesized compounds and proteins, with binding affinities ranging from -9.6 to -6.8 kcal/mol. Notably, diethyl (4-biphenyl (4-phenyldiazenyl) phenylamino) methylphosphonate (4b) demonstrated the highest efficiency, making it a promising antibacterial candidate according to both experimental and computational assessments.

Résumé: Printed circuit boards (PCBs) are basic parts of electronic goods. Their recycling has attracted worldwide attention due to their ever-increasing production, poor environmental safety, and recovery value. The current study aims to evaluate the ecological treatment of PCBs by bacteria indigenous to e-waste-contaminated soils. Bacterial cultures were isolated using a chemically defined medium containing PCBs pieces as the sole carbon source. Phenotypic characterization and partial 16S rRNA gene sequencing of isolates HB3 and HB4 supported their identification as Pseudomonas aeruginosa and Achromobacter sp., respectively. At pH 7, the P. aeruginosa strain caused stronger PCBs degradation (weight loss almost 8%) than Achromobacter sp., while at pH 11 Achromobacter sp. was dominant leading to a 42% weight loss. Surface modifications of the treated PCBs were demonstrated by scanning electron microscopy images showing cracks and fissures. Energy-dispersive X-ray analysis indicated the presence of magnesium, aluminum, silica, calcium, titanium and copper as additional elements on the surface of the treated PCBs. Further, fourier transform infrared spectroscopy analysis suggested the presence of the O–H band (3678.1 cm–1), benzene rings (1601.07 cm–1) and C–H bonds (883 cm–1) in bacterial-treated PCBs. This study highlights the ability of indigenous soil bacteria to degrade PCBs without pre-treatment steps.