Phyto-mediated synthesis of zinc oxide nanoparticles of Berberis aristata: Characterization, antioxidant activity and antibacterial activity with special reference to urinary tract pathogens.

The field of nanoscience or nanotechnology is gaining popularity day by day and it is now well established field of interdisciplinary sciences. Nanoparticles are synthesized by various methods but suffer from few limitations such as toxicity. To overcome the limitations of various synthesis methods, the focus has shifted to new radius which involves biological organisms such as plants i.e. green synthesis. This phyto-mediated approach using various plant parts and extracts thereof, is considered to be new, simple and cheaper strategy to synthesize metal nanoparticles. In the present work, we describe a simple, eco-friendly and low-cost procedure for biosynthesis of zinc oxide nanoparticles (ZnO NPs) using leaf extract of medicinally important plant, Berberis aristata. The synthesized zinc oxide nanoparticles was subsequently characterized by using UV-Visible spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and Dynamic Light Scattering (DLS) which proved the synthesized ZnO NPs to fall in the range of nanoparticles. Synthesized ZnO NPs were further characterized and screened for antimicrobial and antioxidant activity. ZnO NPs displayed antibacterial activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Bacillus cereus, Serratia marcescens but not for Proteus and Salmonella Typhi. ZnO NPs displayed antibacterial activities and moderate antioxidant potential. Our results display the synthesized ZnO NPs to fall in an important class of potential antibacterial, antioxidant agents and effective against urinary tract infections.

Chandra H ，Patel D ，Kumari P ，Jangwan JS ，Yadav S ... -  《-》

Biosynthesis, characterization and antimicrobial activities of zinc oxide nanoparticles from leaf extract of Mentha pulegium (L.).

The synthesis of metal and semiconductor nanoparticles is an expanding research area due to the potential applications in the development of novel technologies. In the present study, a simple and eco-friendly synthesis of zinc oxide nanoparticles (ZnO NPs) using leaf extract of Mentha pulegium L. has been used. The biosynthesized ZnO NPs were characterized various techniques such as UV-Vis absorption spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FT-IR). The XRD data showed the crystalline nature of the nanoparticles and EDX measurements indicated the high zinc content of 56.26% and also oxygen with 43.74%. FT-IR confirmed the presence of functional groups of both leaf extract and ZnO NPs. The particles size and morphology determined from FE-SEM and TEM and UV visible absorbance spectrum of ZnO NPs exhibited the absorbance band at 370 nm. The synthesized ZnO nanoparticles as potential antibacterial agent has been studied on Escherichia coli and Staphylococcus aureus. These results indicate that aqueous extract of Mentha pulegium (L.) are effective reducing agents for green synthesis of ZnO NPs with significant antimicrobial potential.

Rad SS ，Sani AM ，Mohseni S 《-》

Mycogenic Synthesis of Extracellular Zinc Oxide Nanoparticles from Xylaria acuta and Its Nanoantibiotic Potential.

The study aimed to find an effective method for fungal-mediated synthesis of zinc oxide nanoparticles using endophytic fungal extracts and to evaluate the efficiency of synthesized ZnO NPs as antimicrobial and anticancerous agents. Zinc oxide nanoparticles (ZnO NPs) were produced from zinc nitrate hexahydrate with fungal filtrate by the combustion method. The spectroscopy and microscopy techniques, such as ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), and transmission electron microscopy (TEM) with selected area electron diffraction (SAED), were used to characterize the obtained product. Antibacterial activity on Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) samples was tested by broth microplate dilution technique. ZnO NPs antifungal activity was determined against plant pathogenic and regular contaminating fungi using the food-poison method. The anticancerous assay of the synthesized ZnO NPs was also investigated by cell uptake, MTT assay, and apoptosis assay. The fungal synthesized ZnO NPs were pure, mainly hexagonal in shape and size range of 34-55 nm. The biosynthesized ZnO NPs could proficiently inhibit both Gram-positive and Gram-negative bacteria. ZnO NPs synthesized from fungal extract exhibited antifungal activity in a dose-dependent manner with a high percentage of mycelial inhibition. The cell uptake analysis of ZnO NPs suggests that a significant amount of ZnO NPs (1 μg/mL) was internalized without disturbing cancer cells' morphology. As a result, the synthesized ZnO NPs showed significant anticancer activity against cancer cells at 1 μg/mL concentration. This fungus-mediated synthesis of ZnO NPs is a simple, eco-friendly, and non-toxic method. Our results show that the synthesized ZnO NPs are an excellent novel antimicrobial and anticancer agent. Further studies are required to understand the mechanism of the antimicrobial, anticancerous action of ZnO NPs and their possible genotoxicity.

Sumanth B ，Lakshmeesha TR ，Ansari MA ，Alzohairy MA ，Udayashankar AC ，Shobha B ，Niranjana SR ，Srinivas C ，Almatroudi A ... -  《International Journal of Nanomedicine》

Green Synthesis of Zinc Oxide Nanoparticles from Pomegranate (Punica granatum) Extracts and Characterization of Their Antibacterial Activity.

Ifeanyichukwu UL ，Fayemi OE ，Ateba CN 《MOLECULES》

Antibacterial and antioxidant properties of biosynthesized zinc oxide nanoparticles from Ceropegia candelabrum L. - An endemic species.

Zinc oxide nanoparticles (ZnO-NPs) were synthesized for the first time from any of the species of Ceropegia. Presently, ZnO-NPs were synthesized from the leaf extract of Ceropegia candelabrum with zinc nitrate using a simple hydrothermal process. The synthesized ZnO-NPs showed an absorption peak at 320nm which is one of the characteristic features of ZnO-NPs. The FT-IR characterization revealed a spectrum band at 551.93cm-1 corresponding to the functional group metal oxide. SEM images showed agglomeration of nanoparticles with a hexagonal shape. XRD results are in corroboration with SEM images as the synthesized particles were of hexagonal wurtzite shape and the size of the particles was in the range of 12-35nm calculated using Scherrer's formula. The elemental analysis using EDS confirmed high zinc content of 70.48% stating that the process of biosynthesis of nanoparticles was carried out in accordance. The biosynthesized ZnO-NPs offered significant antibacterial potential against S. aureus, B. subtilis, E. coli and S. typhi. The antioxidant results revealed significant (p≤0.05) RSA from 0% to 55.43% (IC50=95.09μgmL-1). The results affirm that biosynthesized ZnO-NPs can be used as an alternative to present-day chemical compounds.

Murali M ，Mahendra C ，Nagabhushan ，Rajashekar N ，Sudarshana MS ，Raveesha KA ，Amruthesh KN ... -  《-》