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In recent years, bio-reinforced composite materials have occupied an important class among the materials of mass use in our daily lives thanks to their potential advantages such as lightness, low cost, ease of implementation, and in particular biodegradation. The latter has been the objective of several studies focusing particularly on poorly biodegradable polymers, among these polymers we find polyamide 6 (PA6). It is a semi-crystalline polymer, distinguished by its good mechanical properties, excellent chemical and thermal stability, and low price compared to other polyamides. In this research, we investigated the impact of reinforcing PA6 with peanut shell powder (PSP), olive pomace powder (OPP), and plaster (PL) on its biodegradation process. Our objective was to determine whether the incorporation of these reinforcements accelerates, delays, or has no effect on PA6 biodegradation. To achieve this, we conducted degradation experiments using the bacterium Alcaligenes faecalis (AF), isolated from the public landfill of Meknes, Morocco. Our findings revealed intriguing insights into the biodegradation behavior of the PA6 composites. Specifically, the incorporation of PSP significantly enhanced PA6 biodegradation, resulting in a notable 38 % weight loss. Conversely, the inclusion of OPP led to a delay in biodegradation, with only a 19 % weight loss observed. Interestingly, the addition of plaster exhibited a biodegradation pattern similar to that of raw PA6. Furthermore, we utilized FTIR and SEM coupled with EDS elemental analysis to confirm the biodegradation of the composites. These techniques provided valuable insights into the structural, morphological, and elemental changes undergone by the composites during the biodegradation process. Overall, our study contributes novel insights into the biodegradation dynamics of PA6 composites reinforced with natural materials. By elucidating the effects of reinforcement on biodegradation, our research paves the way for the development of sustainable and eco-friendly composite materials.

This work describes the synthesis, characterization, and in vitro and in silico evaluation of the biological activity of new functionalized isoxazole derivatives. The structures of all new compounds were analyzed by IR and NMR spectroscopy. The structures of 4c and 4f were further confirmed by single crystal X-ray and their compositions unambiguously determined by mass spectrometry (MS). The antibacterial effect of the isoxazoles was assessed in vitro against Escherichia coli, Bacillus subtilis, and Staphylococcusaureus bacterial strains. Isoxazole 4a showed significant activity against E. coli and B. subtilis compared to the reference antibiotic drugs while 4d and 4f also exhibited some antibacterial effects. The molecular docking results indicate that the synthesized compounds exhibit strong interactions with the target proteins. Specifically, 4a displayed a better affinity for E. coli, S. aureus, and B. subtilis in comparison to the reference drugs. The molecular dynamics simulations performed on 4a strongly support the stability of the ligand–receptor complex when interacting with the active sites of proteins from E. coli, S. aureus, and B. subtilis. Lastly, the results of the Absorption, Distribution, Metabolism, Excretion and Toxicity Analysis (ADME-Tox) reveal that the molecules have promising pharmacokinetic properties, suggesting favorable druglike properties and potential therapeutic agents.

The search for novel powerful antimicrobial and antioxidant agents is considered a dynamic field in medicinal chemistry. In this context, a series of spiropyrazoline indolin-3-one congeners were assessed for their in vitro bioactivities, and in-silico studies were conducted to support the experimental results. The antimicrobial screening of the spiropyrazoline oxindole congeners against the selected microbe strains (Staphylococcus aureus (CECT 976), Bacillus subtilis (DSM 6633), Escherichia coli (K12), and Candida albicans (ATCC 10231)) exhibited moderate to excellent, compared to control standard antibiotics (Ampicillin, streptomycin and fluconazole). This activity was observed to be tightly dependent upon the nature of the substituents carried by the aromatic rings. Moreover, the tested compounds showed variable dose-dependent antioxidant activity. Notably, congeners 2c, 2d and 2e exhibited a remarkable antioxidant activity, due to the positive impact of the electron-donating groups (CH3 and OCH3) on the antioxidant activity. Density functional theory (DFT) simulations were executed on the target molecules to better understand their structural and electronic properties, as well as to explain the results obtained from the antioxidant activity. The molecular docking studies showed that the studied congeners have good binding affinities and interactions with the target proteins (catalase compound II and CYP51). Moreover, the 100 ns molecular dynamics (MD) simulation analysis was conducted to follow the behavior of the complexes formed between ligand 2e and the target proteins (2CAG and 5V5Z) under in-silico physiological conditions to explore and evaluate its stability over time. MD simulation indicated a stable conformation and binding patterns in a stimulating environment of the congeners (2CAG-2e and 5V5Z-2e). The results of Petra/Osiris/Molinspiration (POM) analyses suggested that all the spiranic cycloadducts have good oral bioavailability and pharmacokinetics without any evidence of observed toxicity. Taken together, our findings provide valuable experimental and theoretical information that will be helpful for designing novel spiranic molecules with potential pharmacological applications.

Novel isoxazole–triazole conjugates have been efficiently synthesized using 3-formylchromone as starting material according to a multi-step synthetic approach. The structures of the target conjugates and intermediate products were characterized by standard spectroscopic techniques (1H NMR and 13C NMR) and confirmed by mass spectrometry (MS). The all-synthesized compounds were screened for their antibacterial activity against three ATCC reference strains, namely Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC BAA-44, and Escherichia coli ATCC 25922 as well as one strain isolated from the hospital environment Pseudomonas aeruginosa. The findings indicate that conjugate 7b exhibits a stronger antibacterial response against the tested Escherichia coli ATCC 25922 and Pseudomonas aeruginosa pathogenic strains compared to the standard antibiotics. Furthermore, hybrid compound 7b proved to have a bactericidal action on the Escherichia coli ATCC 25922 strain, as evidenced by the results of the MBC determination. Moreover, the ADMET pharmacokinetic characteristics revealed a favorable profile for the examined compound, as well as a good level of oral bioavailability. Molecular docking and molecular dynamics simulations were performed to explore the inhibition mechanism and binding energies of conjugate 7b with the proteins of Escherichia coli and Pseudomonas aeruginosa bacterial strains. The in silico results corroborated the data observed in the in vitro evaluation for compound 7b.

In this study, a new bi-nuclear nickel complex [Ni2HL2(EtOH)2](Cl)(EtOH) of a Schiff base ligand, 2-[3-[2-hydroxybenzylideneamino]propyliminomethyl]phenol, was synthesized and characterized using UV/Vis, IR, HRMS, and TGA/DTA analysis. The molecular structure of the obtained complex was corroborated by the single crystal X-ray diffraction technique. It was found in the complex that two molecules of the ligand coordinate with two nickel atoms through azomethine-N and phenoxy-O, resulting in 6-coordinate distorted octahedral geometry, in which two ethanol molecules occupy the axial positions. The dielectric and electrical properties of the obtained samples were studied by impedance spectroscopy at different frequencies (from 1 Hz to 1 MHz) in the temperature range 298–343 K. It is found that the electrical conductivity of the Ni(II) complex is lower than that of the free ligand H2L, suggesting that the complexation traps the charge carriers contained in the ligand.

Quinazolinone and isoxazoline systems have attracted much attention due to their interesting pharmacological properties. The association of these two pharmacophores in a single hybrid structure can boost the biological activity or bring a new one. Inspired by this new paradigm, in the present work we report the synthesis and spectroscopic characterization of new quinazolinone–isoxazoline hybrids. The target compounds were obtained via 1,3-dipolar cycloaddition reactions of arylnitriloxides and N-allylquinazolinone. The synthesized compounds were characterized using spectroscopic techniques such as IR, 1D NMR (1H and 13C), 2D NMR (COSY and HSQC), and high-resolution mass spectrometry (HRMS). The spectral data show that this reaction leads only to the 3,5-disubstituted isoxazoline regioisomer, and that the observed regiochemistry is not affected by the nature of the substituents in the phenyl ring of the dipole. In addition, a theoretical study was performed using density functional theory (DFT) to support the experimental results in regard to the regiochemistry of the studied reactions. The computational mechanistic study was in good agreement with the experimental data.

In this contribution new Cobalt(II), Nickel(II), Copper(II) and Zinc(II) complexes based on the tetradentate ligand [(N1Z,N2Z)-N1,N2-bis((1H-pyrrol-2-yl)methylene)ethane-1,2-diamine] were synthesized and characterized by spectral techniques such as UV–Visible, infrared, nuclear magnetic resonance (NMR, 1H,13C), thermal analysis (DTA and TGA) and mass spectrometry. Results showed that Co (II) and Ni (II) complexes have an octahedral geometry, Zn (II) complex has a tetrahedral structure, and Copper (II) complex has a square planar geometry. Furthermore, based on the molar conductivity values, these complexes were considered as non-electrolytes except the copper complex. The synthesized ligand and their complexes were assessed for their antioxidant and antibacterial activities. All complexes showed greater antioxidant and antibacterial activities with respect to the ligand. In addition, the ligand and its complexes were also tested biologically first on the germination of Lepidium sativum seeds, which is a phytotoxic and antimitotic test, and on the hemolytic and genotoxic behavior of human blood cells. A total inhibition on germination and radicle growth of Lepidium sativum seeds treated with [CuL]Cl22H2O solution was recorded. However, the [CoLCl2]H2O, caused a complete hemolysis of red blood cells and total alteration of nuclei and membranes of leukocytes.

In recent years, due to less environmental pollution, ecological products are recommended more and more by the different environmental unions and cooperation. To achieve this, industries have studied the use of composite materials based on natural resources because of their lightness, their resistance to corrosion, their biodegradability, and their wide availability. In the same context, the current work may open up a new way of developing an original biocomposite material by taking advantage of integrating Olive Pomace Powder (OPP) as a filler on the PA6 matrix. This technical polymer is one of the most widely used polymers thanks to its chemical and physical stability, thermal resistance, low cost, and availability.The dry OPP is used without any additional chemical treatment; it had particle sizes (160–250 μm). The PA6/OPP was prepared thanks to polymerization in situ, a new innovative way to fabricate our biocomposite. The rate of OPP varies from 5% to 20% by weight. The structural, physicochemical, and thermal behavior was determined using FTIR, XRD, DSC, and TGA-DTA techniques. The morphology of the samples was analyzed with the SEM technique. The results show that the addition of OPP does not diminish the properties of PA6 till a ratio of 20% by weight. The density and the crystallinity of PA6/OPP were almost unchangeable than PA6. It was also found that after adding 20% OPP, the crystalization temperature Tc and melting temperature Tm were the same as PA6, while the decomposition temperature Td increases slightly. These results show that this incorporation can be a way to valorize the OPP and on the other hand reduce the cost of the final product fabricating with the PA6 matrix.

Polyamide 6 (PA6, polycaprolactam, Nylon 6) is a thermoplastic polymer widely used in construction, automotive, packaging, etc. It is a semi-crystalline polymer known for its good mechanical properties, and chemical, and thermal stability, with a low price, compared to the other polyamides. PA6 can be synthesized by anionic polymerization of ε-caprolactam, initiated by sodium hydride, and activated by N-acetylcaprolactam. This poorly biodegradable material has quickly proven to be a source of considerable pollution both visually and in terms of ecosystem preservation, particularly due to its increasing annual global production. This issue raises the need to develop environmentally friendly protocols for the degradation of this waste. One of the methods that can prove to be effective is the degradation by microorganisms. The objective of our research is to study the degradation of PA6 by the bacteria Lysinibacillus sp. (LB), Alcaligene faecalis (AF), and Enterococcus faecalis (EF) isolated from the landfill. The three bacteria, isolated and previously identified, were able to show proliferation in minimal media using PA6 as the sole source of carbon and nitrogen. The weight loss of the PA6 pellets was evaluated at 21% for L. bacillus, 27% for A. faecalis, and 13% for E. faecalis after 48 days of incubation. The biodegradation of PA6 was also confirmed by FTIR and SEM coupled to the elemental detector scanning EDS, which revealed the structural, morphological, and elemental changes that PA6 underwent.

Objective: Natural fibers reinforcements have gained increasing attention for the development of biocomposites thanks to their biodegradability and renewability. The search for natural-based reinforcements that improve the biodegradation of plastics while maintaining their physicochemical and mechanical properties is a never-ending task. Herein, we report the preparation of new biocomposites based on polyamide 6 (PA6) matrix and peanut shell powder (PSP) reinforcement. Methodology: The biobased composites were prepared by incorporating different amounts of PSP, from 5% to 20% by weight, and then characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction technique (XRD), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and scanning electron microscope (MEB). Results: Results showed that the addition of PSP did not affect the density of PA6. Its crystallinity was unaffected by the addition of 5%, 10%, and 15% of PSP, while it slightly decreases after the addition of 20% PSP. All analyses showed that the matrix kept its structure after adding a PSP concentration up to 15%, while a higher amount resulted in a new structure. Conclusion: Results of the present work might open a new way towards the development of efficient biocomposites through the valorization of natural fibers.

The title compound, diethyl [(4-{(9H-carbazol-9-yl)methyl}-1H-1,2,3-triazol-1-yl)(benzamido)methyl]phosphonate, was synthesized with excellent yield and high regioselectivity through 1,3-dipolar cycloaddition reaction between the α-azido diethyl amino methylphosphonate and the heterocyclic alkyne, 9-(prop-2-yn-1-yl)-9H-carbazole. The cyclization reaction by “click chemistry” was carried out in a water/ethanol solvent mixture (50/50), in the presence of copper sulfate pentahydrate and catalytic sodium ascorbate. The characterization of the structure of the resulting 1,4-regioisomer was performed by 1D and 2D-NMR experiments, infrared spectroscopy, and elemental analysis.