Simarouba glauca-mediated synthesis of pristine and PEG-functionalized gold nanoparticles: physicochemical characterisation, computational analysis, antimicrobial and anticancer activities

Cervical cancer remains a major health concern, particularly in developing countries. Gold nanoparticles (AuNPs), due to their biocompatibility and optical properties, offer potential in targeted cancer therapy. In this study, ethanolic leaf extract of Simarouba glauca was employed for the green synthesis of Pristine-AuNPs, followed by post-synthetic treatment with polyethylene glycol (PEG) to prepare PEG-functionalized AuNPs. The extract exhibited a total phenolic content of 28 mg GAE g⁻ 1 and 82.68% DPPH radical scavenging activity. FTIR analysis characterised the functional groups present in the leaf extract and PEG-functionalized AuNPs. GC–MS analysis provided tentative library assignments, from which selected molecular candidates were subsequently evaluated using SwissADME, SwissTargetPrediction, and molecular docking to investigate their predicted pharmacokinetic properties and potential protein interactions. Exploratory docking of ethane, 1,1-diethoxy- with the Nischarin PX domain (PDB ID: 3P0C) yielded the lowest calculated binding-energy estimate of −3.64 kcal mol⁻ 1 . AuNP formation was supported by UV–visible spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM–EDX), Dynamic Light Scattering (DLS), Zeta Potential and Transmission Electron Microscopy (TEM) analyses. Based on the MTT assay, PEG-functionalized AuNPs produced a concentration-dependent reduction in relative HeLa-cell viability, reaching 49.96% at 30 µg mL⁻ 1 . Synthesised AuNPs were also employed for antibacterial effects on Micrococcus luteus, which demonstrated a zone of inhibition when exposed to Pristine and PEG-functionalized AuNPs.