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Several fungal endophytes were isolated and screened for their ability to biosynthesize a variety of nanoparticles (NPs), as a potentially simple and eco-friendly method with low cost. Among these fungi, a promising isolate named ORG-1 was found able to synthesize five different NPs types: Co 3 O 4 NPs, CuONPs, Fe 3 O 4 NPs, NiONPs, and ZnONPs. The ORG-1 strain was identified as Aspergillus terreus according to the morphological and molecular studies. Synthesis of these NPs was initially monitored by UV-Vis spectroscopy and further characterized by Fourier transform infrared spectroscopy. X-ray diffraction patterns revealed their crystalline structure. Dynamic light scattering analysis was applied to study the particle size distribution and stability. Transmission electron microscope studies indicated the morphology of the synthesized NPs. Additionally, the biological activities of the in vitro antioxidant and antimicrobial potentials were evaluated. Co 3 O 4 NPs, CuONPs, Fe 3 O 4 NPs, NiONPs, and ZnONPs showed promising antioxidant activity with 50% inhibitory concentrations of 85.44, 96.74, 102.41, 87.41, and 108.67 μg mL -1 , respectively. The synthesized NPs exhibited potent antimicrobial activities against several plant and human pathogens. To our knowledge, this is the first report on the use of one microbial strain for the synthesis of a variety of NPs. This study suggests endophytic fungi as new and alternate platforms with an exceptional potentiality for the synthesis of NPs with promising activities. KEY POINTS: • Discovery of a promising endophytic fungus for synthesis of five different types of NPs. • Mycosynthesis and characterization of all the synthesized NPs were investigated. • The synthesized NPs showed promising antioxidant and antimicrobial activities.

Aims: This study was aimed to screen and isolate soil and endophytic fungi with the ability to biosynthesize stable silver nanoparticles (SNPs) with antimicrobial and antiproliferative activities. Methodology and results: A total of 60 fungal isolates isolated from soil and plant samples were screened for their ability to biosynthesize SNPs. Among which, 21 isolates have supported the biosynthesis of SNPs. Furthermore, the endophytic isolate PRR2.1 synthesized highly thermostable SNPs with long shelf life. The PRR2.1 isolate was identified as Albifimbria verrucaria by morphological and molecular means. The synthesis of SNPs was initially monitored by UV-Vis spectroscopy. Further characterization by transmission electron microscopy, X-ray diffraction and dynamic light scattering revealed well-dispersed spherical crystalline in nature SNPs with a mean size of 14 nm and zeta potential of - 24.47 mV. Fourier transform infrared spectroscopy showed the presence of biomolecules adsorbed on the surface of biosynthesized SNPs responsible for their synthesis and stability. The mycosynthesized SNPs exhibited stronger antifungal activity against pathogenic strains of Aspergillus niger, A. flavus, A. fumigatus and Candida albicans with respect to its antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacillus cereus and Klebsiella pneumoniae compared to standard antifungal itraconazole and antibiotic cefadroxil with mostly consistent minimum inhibitory concentration of 5.31 µg/mL. The biosynthesized SNPs demonstrated dose-dependent in vitro antiproliferative activity against cancerous HeLa cell line with IC50 value of 2.52 µg/mL and less cytotoxic activity against WI-38 (normal human lung fibroblasts) cell line with CC50 value of 10.2 µg/mL. Conclusion, significance and impact of study: These results show the potential of endophytic fungi biosynthesized SNPs as possible biofriendly, safe and efficient antimicrobial agents with promising antiproliferative activity and low cytotoxicity, which can be furtherly implemented in various biomedical and biotechnological applications. [ABSTRACT FROM AUTHOR]

Phthalazine and phthalazinone derivatives are important owing to their significant biological activities and pharmacological properties. Herein, a benzoic acid derivative (2), a benzoxazin-1-one derivative (3), and an oxophthalazin-2(1 H)-yl)acetohydrazide (13) are utilized as precursors to construct a novel series of phthalazinones bearing various valuable functional groups in excellent yields via several simple and promising approaches. Finally, the antimicrobial activity of the newly synthesized phthalazines is screened against different microbial strains; namely, Gram-negative and Gram-positive bacteria utilizing Amoxicillin as a standard drug. [ABSTRACT FROM AUTHOR]

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Antimicrobial resistance is a global public health threat that signals the identification of new antimicrobial agents with different modes of action. The synthesis and the antimicrobial evaluations of a series of 2-oxonicotinonitriles (2-ONNs) derivatives are described. The parent 2-ONN derivative 3 was synthesized by one-pot four-component reaction: acetyl cyclohexane, p-anisaldehyde, ethyl cyanoacetate, and NH4OAc, in high yield. Density functional theory geometrical equilibrium of the tautomeric forms of 3 concluded the predominance of the keto tautomer. Base-catalyzed coupling of 3 with several organohalides/alkylating agents provided branching and solubilizing groups to the 2-ONN derivative 3. Alkylated ONNs and free acyclic nucleoside mimics/glycosides derived from the 2-ONN derivative 3 were tested for their antibacterial and antifungal activities. The acyclic nucleoside mimic 13 and the N1-propargyl derivative 16 and N1-allyl derivative 18 showed significant activities against S. aureus, and M. luteus; meanwhile, significant anti-E. coli activity was observed with compounds 3 and 18. On the other hand, a significant antifungal activity was observed with 3 and with its N1-glucoside derivatives 4 and 5 against Candida albicans and Aspergillus niger. [ABSTRACT FROM AUTHOR]