The invention of an easy synthetic approach for extremely impactful nanomaterials (NMs) is one of the crucial research areas in modern science and engineering. In the present work, we describe a cost-effective, simple, rapid and environmentally gracious biogenic fabrication of nickel/nickel oxide nanoparticles (Ni/NiO NPs) using Gymnema sylvestre as a natural fuel. The textural characteristics of as-prepared Ni/NiO NPs were explored using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectra (DRS), photoluminescence spectroscopy (PL), field-emission scanning electron microscope (FESEM), energy dispersive X-ray analysis (EDX), and high-resolution transmission electron microscopy (HRTEM). XRD affirmed the crystalline nature and phase formation of Ni/NiO NPs. The FTIR spectrum ascertains the formation of Ni/NiO NPs, and the band gap of 4.29 eV is revealed from DRS studies. Ni/NiO NPs display an intense emission peak at 576.2 nm in their PL spectrum. The fabrication of pseudo-spherical Ni/NiO NPs was displayed by FESEM and HRTEM images. The particle size obtained from HRTEM was 21 nm, which resembles the median crystallite size ascertained from the XRD data. Additionally, the plausible mechanism for Ni/NiO NPs formation is illustrated. Moreover, as-synthesized Ni/NiO NPs displayed considerable antifungal potential against Candida albicans and Aspergillus niger. Results revealed that the Gymnema sylvestre leaves extract can synthesize Ni/NiO NPs with appealing biological effectiveness for application in the nanomedicine sector.

A new series of 2‐aryl‐5‐((2‐arylthiazol‐4‐yl)methyl)‐1,3,4‐oxadiazole derivatives was synthesized by condensation of 2‐(2‐substituted thiazol‐4‐yl)acetohydrazide with aryl aldehydes followed by oxidative cyclocondensation using iodobenzene diacetate. The structure of synthesized compounds was characterized by IR, NMR, and mass analysis. All the newly synthesized compounds were evaluated for their in vitro antimicrobial activity. Some of the compounds showed moderate antimicrobial activity.

A new series of 2-(5-aryl-1-phenyl-1H-pyrazol-3yl)-4-aryl thiazoles (10a−ab) have been synthesized by a cyclocondensation reaction of 5-aryl-1-phenyl-1H-pyrazole-3-carbothioamide (7a−d) with substituted phenacyl bromide (8a−f). The structure of newly synthesized 2-(5-aryl-1-phenyl-1H-pyrazol-3-yl)-4-aryl thiazole (10a−ab) derivatives was characterized by spectroscopic analysis. The compounds 10a−ab were evaluated for in vitro antibacterial activity against Escherichia coli (NCIM 2574), Proteus mirabilis (NCIM 2388), Bacillus subtilis (NCIM 2063), Staphylococcus aureus (NCIM 2178), and in vitro antifungal activity against Aspergillus niger (ATCC 504) and Candida albicans (NCIM 3100). Among the twenty-eight pyrazolyl-thiazole derivatives, six compounds, 10g, 10h, 10i, 10j, 10o, and 10t, showed good activity against P. mirabilis; four compounds 10q, 10u, 10y, and 10z showed good activity against S. aureus; and twenty-four derivatives showed good antifungal activity against A. niger. Compounds 10g, 10q, 10r, 10s, and 10ab showed comparable activity with respect to the reference drug Ravuconazole. Thus, the significant antimicrobial activity of 2-(5-aryl-1-phenyl-1H-pyrazol-3-yl)-4-aryl thiazole (10a−ab) derivatives prompted that these scaffolds could assist in the development of lead compounds to treat microbial infections.

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A new series of 3,5-bis(2-arylthiazol-4-yl)-1,2,4-oxadiazole (8a-o) has been synthesized by modified reaction conditions. The reaction of ester 7a with N 0hydroxy-2-phenylthiazole-4-carboximidamide 6a using NaOH in DMSO gave the formation of product 8a up to 40% yield. In the second method, the reaction with K 2 CO 3 in toluene at reflux conditions gave a 50% yield. In the third method, the reaction condition was modified. The ester 7a was hydrolyzed to acid 9a. The reactions of acid 9a using N,N-dimethyl amino pyridine (DMAP) in N,N-dimethylformamide (DMF), followed by the addition of N-(3-dimethylaminopropyl)-N 0 -ethylcarbodiimide hydrochloride (EDCÁHCl), and then N 0hydroxy-2-phenylthiazole-4-carboximidamide 6a, furnished a 65% yield of 8a.The compounds 8b-o were synthesized using DMAP and EDCÁHCl as coupling reagents and gave 60%-72% yields. The structure of newly synthesized compounds was confirmed by spectral analysis. The synthesized compounds were screened for in vitro antimicrobial activity against Escherichia coli (NCIM 2574), Proteus mirabilis (NCIM 2388), Bacillus subtilis (NCIM2063), Staphylococcus albus (NCIM 2178), Candida albicans (NCIM 3100), and Aspergillus niger (ATCC 504). Among the 8a-o derivatives, eight compounds 8c, 8e, 8f, 8g, 8i, 8j, 8k, and 8l showed good activity S. albus with a MIC 31.25-62.5 μg/mL.