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In order to address the challenges associated with antibiotic resistance by bacteria, two new complexes, Ni(II) and Zn(II), have been synthesized using the conventional method based on Schiff base ligand (E)-2-((5-bromothiazol-2-yl) imino) methyl) phenol. The Schiff base ligand (HL) was synthesized using salicylaldehyde and 5-(4-bromophenyl)thiazol-2-amine in both traditional and efficient, ecologically friendly, microwave-assisted procedures. The ligand and its complexes were evaluated by elemental analyses, FTIR spectroscopy, UV-Vis spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA) and magnetic susceptibility. The ligand and its complexes were tested for antibacterial activity against three Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus ATCC 43300 and Enterococcus faecalis ATCC 29212) and three Gram-negative bacteria (Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 700603). The findings demonstrate the potent activity of the ligand and its complexes against selective bacteria but the Ni(II) complex with MIC values ranging from 1.95 to 7.81 µg/mL outperformed all other compounds, including the widely used antibiotic Streptomycin. Furthermore, the docking study provided evidence supporting the validity of the antimicrobial results, since the Ni complex showed superior binding affinity against to E. coli NAD synthetase, which had a docking score (−7.61 kcal/mol).

A series of novel compounds, mono-5-isoxazolidines, and bis (5-isoxazolidines) derivatives, were prepared as bicycloadducts. The new series of isoxazolidines were designed and synthesized via 1,3-dipolar cycloaddition reaction of nitrones with 3,9-Divinyl-2,4,8,10-tetra oxaspiro (5-5) undecane in the context of new antimicrobial and antioxidant drugs discovery and were fully characterized by FT-IR, 13C-NMR, and 1H-NMR spectroscopy. The physicochemical properties of all the novel cycloadducts, like bioactivity score and lipophilicity, were predicted using calculative methods. Similarly, the pharmacokinetic properties such as metabolism, absorption, distribution, and excretion (ADME) were also predicted. Most of the tested compounds exhibited antimicrobial properties to varying degrees against various bacterial species, including the Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli, and the Gram-positive bacteria Streptococcus pyogenus and Staphylococcus aureus, Antifungal properties were also observed against the tested fungi like Candida albicans, Aspergillus niger, and Aspergillus clavatus. The activity data exhibited that most compounds have high activity as compared to the standard drugs. In the range of graded doses, the results of some selected compounds revealed that some are high antioxidants while others are moderate or weak antioxidants. As evidenced by the molecular docking studies, the synthesized compounds showed good binding mode better than a standard drug, against the protein of a Pantothenate Synthetase enzyme (PDB-2X3F).

Objective: To investigate the effect of temperature and pressure on supercritical CO2 extraction of Triognella foenum graecum Linn seeds, to determine the optimal condition which leads to highest percentage of the accumulative yield and revealing the chemical composition of supercritical CO2 extract. Methods: Temperatures in the range of 40â60 °C and pressures in the range of 10â25 MPa were used. FTIR and GCâMS analysis were used to detect the bioactive compounds present in the extract. The broth dilution method and slope method were used to evaluate the anti-microbial and anti-tuberculosis activities and the in vitro anti-malarial assay was carried out according to the micro assay protocol of Rieckmann and his co-workers. Results: The temperature was more affected than the pressure on the extraction performance and the highest yield of the extract (3.111%) was attained at 60 °C and 10 MPa. FTIR and GCâMS showed that the chemical composition of the extract included conjugated linoleic acid methyl ester as the major active principle (with concentration of 72.28%), followed by saturated fatty acid methyl esters (16.03%), steroids (8.09%) and organic siloxane compound (3.61%). The extract showed moderate anti-bacterial activity with MIC values 100, 250, 125 μg/mL towards Escherichia coli, Staphylococcus aureus and Streptococcus pyogenus respectively. It exhibited high inhibition effect towards the fungi Candida albican with MFC value (250 μg/mL). The extract had low anti-tuberculosis activity with MIC value (100 μg/mL) and comparable MIC value (0.29 μg/mL) towards Plasmodium flaciparum. Conclusions: Supercritical CO2 extraction as alternate and green technology is performed successfully to extract the bioactive compounds from the seeds of T. foenum graecum Linn and it is concluded that this extract can be used as an alternate source of synthetic anti-biotic drugs. Keywords: Anti-bacterial, Anti-fungal, Anti-malarial, Anti-tuberculosis, ScâCO2 extraction, Triognella foenum graecum Linn

(Z)-N′-(4-methoxybenzylidene)benzohydrazide (HL) and its Ni(II) complex (Ni(II)-2L) were synthesized using eco-friendly protocols. The single X-ray crystal structure of Ni(II)-2L was solved. Moreover, the structural properties were evaluated using Fourier transform infrared, proton nuclear magnetic resonance, mass, and Ultraviolet/Visible spectroscopy. The diamagnetic and thermal stability were assessed using magnetic susceptibility and thermogravimetric analysis, respectively. The biological activities of both HL and Ni(II)-2L (62.5–1000 μg/mL) against Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial and fungal (Candida albicans, Aspergillus niger, and Aspergillus clavatus) species were studied using the minimum inhibitory concentration (MIC) tests method in reference to Gentamycin and Nystatin standard drugs, respectively. The results revealed an affordable, environmentally friendly, and efficient synthetic method of HL using water as a green solvent. The Ni(II)-2L complex crystallized in a distorted square planar, P21/n space group, and one Ni(II) to two bidentate negatively charged ligand ratio. The analysis of biological activity revealed higher activity of the complex against S. aureus and S. pyogenes (bacteria) and A. niger and A. clavatus (fungi) compared to the ligand. However, the highest activity was at a MIC of 62.5 μg/mL for the complex against S. pyogenes and for the ligand against E. coli. Therefore, both HL and Ni(II)-2L could be promising potential antimicrobials and their selective activity could be an additional benefit of these bioactive materials.