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In this paper, we report a highly regioselective 1,3-dipolar cycloaddition (1,3-DC) reaction of nitrilimines with thioaurone derivatives that afforded the hitherto unreported spiropyrazolines. Spectroscopic and spectrometric data were utilized to confirm the structure of all products and elucidate the reaction’s regiochemistry. A mechanistic study was performed within the Molecular Electron Density Theory (MEDT) at the B3LYP/6-311G(d,p) computational level to explain the regioselectivity observed. The electron localization function (ELF) topological analysis confirms the carbenoid-type (cb-type) mechanism of the cycloaddition reactions between nitrilimines and thioaurones. The intermolecular interactions between reagents in this reaction account for the regioselectivity observed experimentally.

In the present work, we assessed the antioxidant, antibacterial, and antifungal activities of chemically defined Artemisia mesatlantica Maire (EOAM) essential oils. The GC-MS analysis of EOAM showed the presence of active promising active compounds. EOAM showed important antioxidant capacity through DPPH, FRAP and TAC assays. The in vitro antimicrobial screening showed that EOAM had antibacterial activity, with inhibition zones ranging from 20.67 to 38.35 mm on solid media and inhibitory doses of 2.34 to 4.78 µg/mL on liquid media. It also exhibits antifungal activities, with inhibition diameters ranging from 15.67 to 61.57 mm at doses from 2.90 to 12.54 µg/mL. EOAM was resistant to Aspergillus flavus (A. flavus). In addition, molecular docking, molecular dynamics simulations, and ADMET analyses validated in vitro activities. This research suggests that A. mesatlantica (EOAM) may fight drug-resistant bacteria. These results demonstrate the potential of EOAM to produce novel antioxidant and antibacterial solutions.

Nucleoside derivatives are essential to medicinal chemistry because they provide biologically active drugs. A 5´-O-palmitoyl derivative (2) was obtained by directly treating cytidine (1) with palmitoyl chloride. New antimicrobial compounds were developed by transforming the 5´-O-acyl derivative into 2´,3´-di-O-acyl derivatives (3-7) with several functionalities. Physicochemical, spectroscopic, and elemental investigations were used to determine the structures of the synthesized compounds. XRD confirmed the crystalline structure of the synthesized compounds. Compounds 3 and 5 exhibited good antibacterial and antifungal activity against bacteria and fungi in vitro. MIC and MBC investigations were performed on compounds 3 and 5 on the basis of their effectiveness. Most of the compounds resulted in >77% fungal mycelial growth. Compound 6 had antiproliferative effects on EAC cells in vitro, with an IC50 value of 1001.11 µg/ml. A DFT study was used to calculate the FMO and MEP parameters, whereas molecular docking identified microbial pathogen prescription drug possibilities. In silico docking studies of cytidine derivatives against the 4URO and 6COX receptors revealed that compounds 3 and 6 had the best docking. In a stimulating environment, a 100-ns MD simulation revealed stable conformation and binding patterns. MD simulation and MM-PBSA analysis of the 3-4URO and 6-6COX complexes indicated good receptor-best-docked molecule interactions. Finally, in vitro and in silico, SAR studies, the acyl chains, (CH3(CH2)10CO-) and (C6H5CH=CHCO-) incorporated into sugar moieties were shown to have the most promising antimicrobial/anticancer drug-targeting potential.

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.

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.

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.

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.

Artemisia negrei (A. negrei) and Artemisia aragonensis (A. aragonensis) are in the family Asteraceae, which has been used in traditional medicine. The use of plant-derived insecticides has become a promising strategy to reduce the harmful effects of synthetic insecticides and overcome the bio-resistance of pest insects to insecticides. In this regard, the purpose of the current study was to determine the chemical composition and evaluate insecticidal effects of essential oils (EOs) extracted from A. negrei (EON) and A. aragonensis (EOA). Notably, all chemical constituents present in the EOs were identified through GC-MS analysis, whilst the insecticidal properties against Callosobruchus maculatus Fab. (C. maculatus) were investigated by use of in vitro an in silico approaches. The obtained results showed that both tested EOs present a significant insecticidal effect against C. maculatus, which increased significantly upon the dose used in both contact and inhalation tests. The lethal concentrations (LC50) for the inhalation test were found to be 2.1 and 2.97 μL/L, while in the contact test they were 2.08 and 2.74 μL/L of air for EON and EOA, respectively. At 5 μL/L of air, the spawn reduction rate was 88.53 % and 77.41%, while the emergence reduction rate was 94.86% and 81.22% by EON and EOA, respectively. With increasing doses of up to 20 μL/L of air, the reduction in individual emergence reached 100% by the two oils tested after 36 h of treatment. In addition, Molecular docking (MD) simulations supported the in vitro findings and indicated that certain identified components in EOA and EON exhibited stronger hydrogen bonding interactions with the target receptors. Interestingly, the prediction of ADMET properties indicates that the molecules investigated have great pharmacokinetic profiles with no side effects. Taken together, our findings suggest that EOA and EON may exert both potential contact and inhalation insecticidal actions and could be used as an alternative tool for the control of this major insect pest of stored products.

Artemisia annua (AA) is an aromatic plant belonging to the Asteraceae family, which has long been known for its several medicinal virtues. In addition, essential oils (EOs) extracted from AA have a wide range of therapeutic properties. Therefore, this study aimed to investigate the phytochemical composition, anti-microbial, and anti-oxidant properties of Artemisia annua essential oil (EOAA). EO was extracted, and its chemical constituents were ascertained by the use of GC-MS analysis. EOAA shows remarkable antioxidant capacities of DPPH free radical scavenging with an IC50 value of 29 ± 5.3 μg/mL and ferric reducing antioxidant power with an EC50 value of 9.21 ± 0.3 µg/mL, and it also has a good total antioxidant capacity of 911.59 ± 115.71 milligrams of ascorbic acid equivalence per gram of EO (mg AAE/g EO). Moreover, the in vitro antimicrobial screening results indicate that EOAA has shown promising antibacterial activity, especially against the Escherichia coli strain, and it also shows significant antifungal activity against Fusarium oxysporum and Candida albicans yeasts. Taken together, our findings highlight the importance of EOAA as a source of strong antioxidant and antimicrobial agents, which could be used as an alternative form to control free radicals and combat drug-resistant microbes.