Green Synthesis of Silver Nanoparticles Using Root Extract of Gomphrena vaga Mart.: Metabolomic Insights Into Nanoparticle Formation and Antimicrobial Activity

ABSTRACT

The rise of multidrug‐resistant bacteria demands innovative antimicrobial agents that combine green chemistry principles for synthesis with high activity and a biogenic framework for sustainable agent development. This study pioneers the use of Gomphrena vaga Mart. root extract (GVRE) for the green synthesis of silver nanoparticles (AgNPs), elucidating the phytochemical compounds involved in nanosilver formation and their antimicrobial‐metabolic activity. UV‐Vis and TEM confirm spherical and ultrasmall AgNPs (4.3 ± 0.1 nm) with surface plasmon resonance at 450 nm, while LC‐MS/MS identifies key metabolites, such as hesperidin, ferulic acid, and oleanolic acid, as possible reducing and capping agents. The synthesized AgNPs show good physicochemical stability, measured by DLS, over five months of storage and demonstrate, in initial studies, significant activity against both Gram‐positive and Gram‐negative pathogens, attributed to their ultrasmall size, which facilitates membrane penetration. Using NMR metabolomics, we reveal metabolic reprogramming in Staphylococcus aureus , with AgNP@GVRE downregulating TCA cycle intermediates and upregulating phenylalanine, suggesting impaired energy production and redirected carbon flux. This work integrates phytochemistry and systems biology to unravel how plant‐derived metabolites govern nanomaterial functionality, highlighting AgNP@GVRE as a promising sustainable antimicrobial agent.