Physicochemical and Biological Properties of Copper Oxide Nanoparticles Synthesized from Mallotus philippensis
Umakant Pradhan, Shivani Singh, Purusottam Majhi, Anunay Toppo, Awadhesh Kumar ShuklaIntroduction:
The extract of Mallotus philippensis (M. philippensis) leaves was utilized to synthesize copper oxide nanoparticles, which were subsequently evaluated for antifungal activity against the phytopathogenic fungus Alternaria alternata. A. alternata causes leaf spots and blights in more than 380 plant species, leading to significant reductions in crop yields.
Methods:
Copper oxide nanoparticles were characterized using techniques such as UV-visible spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ZETA potential and PDI, scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM). The antifungal and antioxidant activities of the nanoparticles were evaluated, and molecular docking was performed to investigate possible interactions between the nanoparticles and proteins of selected phytopathogenic fungi.
Results:
UV-visible spectrophotometer analysis showed a surface plasmon resonance band of nanoparticles at 350 nm. The nanoparticles ranged between 5 and 44 nm in size, with an average value of 22 nm observed under a high-resolution transmission electron microscope. The antifungal activity of nanoparticles showed inhibition of radial growth of A. alternata by 74.13% at a concentration of 1.5 mg/mL. At a concentration of 0.5 mg/mL, inhibition of A. alternata growth was 40.45%. The antioxidant activity was reported as 57% and 90% through DPPH and ABTS assays, respectively, at a concentration of 80 μg/mL.
Discussion:
Nanoparticles interact with lipids and proteins of fungal cells, disrupting the cell wall, cell membrane, and other organelles, which contributes to their antifungal action. Molecular docking analysis supports the potential interaction between nanoparticles and fungal proteins. Copper oxide nanoparticles have been reported to neutralize reactive oxygen species and other free radicals, indicating their antioxidant activity.
Conclusion:
Copper oxide nanoparticles synthesized using M. philippensis leaf extract were found to be effective antifungal and antioxidant agents, demonstrating their potential for application in agriculture.