The synthesis of metal nanomaterials is a timely topic due to their widespread use in fields such as crop protection, the environment, medicine, and engineering. Green synthesis of nanoparticles, which uses plant extracts instead of industrial chemical agents to reduce metal ions, has been developed to decrease costs, reduce pollution, and improve environmental and human health safety. In this paper, silver nanoparticles (AgNPs) were synthesized from the flower extract of Jasminum nudiflorum. The green synthesized AgNPs were characterized by UV-Vis, FTIR, XRD, SEM, and other technologies. The antifungal activity of the prepared AgNPs against Alternaria longipes was tested using the plate method, the concentration dilution method, and other methods, and the antioxidant activity of the prepared AgNPs was evaluated by DPPH and hydroxyl free scavenging methods. The results showed that AgNPs synthesized from J. nudiflorum flower extract have a face-centered cubic structure (fcc), and the average grain size of the nanoparticles is 13 nm; they are also mainly spherical in shape. Additionally, the concentration of AgNPs (ranging from 16 to 128 μg/mL) significantly inhibited the mycelial growth of A. longipes in comparison to the control. The inhibitory rate gradually increased with increasing AgNP concentration, ranging from 70.64% to 79.60% at a concentration of 128 μg/mL. The minimum inhibitory concentration was observed at 32 μg/mL. AgNPs induced overaccumulation of MDA in A. longipes, resulting in cell membrane damage and nucleic acid leakage. Moreover, the AgNPs have significant antioxidant properties, which increase with increasing concentration. The clearance rate of DPPH was 25.46 ± 0.90% when the concentration of AgNPs was 8 μg/mL, and the clearance rate of the hydroxyl radical was 28.62 ± 0.59% when the concentration of AgNPs was 128 μg/mL. Thus, the flower extract from J. nudiflorum holds potential as an environmentally friendly and green alternative for the synthesis of AgNPs, which have antifungal and antioxidant potential.
Keywords: AgNPs; Jasminum nudiflorum; antifungal activity; antioxidant activity; green synthesis.