Sustainable production of silver nanoparticles from waste part of Litchi chinensis Sonn. and their antibacterial evaluation

Pak J Pharm Sci. 2022 Jan;35(1):85-94.

Abstract

In our study, waste parts of Litchi chinensis cultivar Surakhi were selected for the production of silver nanoparticles. Qualitative and quantitative analysis revealed peel extracts rich in alkaloids, flavonoids, saponins, steroids, phenolics, tannins as compared to seed extracts. Two different types of nanoparticles (PAN and PMN) were prepared from Litchi chinensis peel using crude aqueous and methanolic extracts. During synthesis, colour variations were observed (brown to blackish brown) and were characterized by UV VIS spectrophotometry. Protein and alkaloids as powerful stabilising agents forming silver nanoparticles were verified by FTIR. Scanning electron microscopy (SEM) analysis of silver nanoparticles shown to be less homogeneous and spherical in form. For PAN and PMN the particle size of silver nanoparticles was 6.9 nm and 7.9 nm respectively with the primitive face-centered cubic phase measured from the XRD pattern. Energy dispersive X-ray spectrometers profile confirmed the strong signal for elemental silver. The antibacterial activity of PAN and PMN against a diverse group of gram positive and gram negative bacterial strains were determined using an agar well diffusion assay. Both types of silver nanoparticles prepared were found effective against Alcaligenes faecium with highest antibacterial activities recorded (20mm±0.14 and 18mm±0.14). Minimal inhibitory concentration was found to be 15μg/ml for both PAN and PMN against Alcaligenes faecium.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacteria / drug effects*
  • Conservation of Natural Resources
  • Food Industry
  • Fruit / chemistry
  • Industrial Waste
  • Litchi / chemistry*
  • Metal Nanoparticles / chemistry*
  • Microbial Sensitivity Tests
  • Silver / chemistry
  • Silver / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Industrial Waste
  • Silver