isolation and in silico evaluation of antibacterial secondary metabolites from endophytic fungus aspergillus niger aia1

Endophytic fungi are a rich source of bioactive secondary metabolites with potential antibacterial properties. this study investigates the secondary metabolites of aspergillus niger aia1, an endophytic fungus isolated from the roots of neem (azadirachta indica a. juss.), focusing on their antibacterial activity and molecular interactions. the fungal biomass was macerated with ethyl acetate and fractionated into n-hexane, dichloromethane (dcm), and methanol extracts. antibacterial activity was assessed using the agar diffusion method against staphylococcus aureus, methicillin-resistant s. aureus (mrsa), and escherichia coli. compound 1 was isolated from the dcm fraction and characterized using uv-vis, ir, lc-ms/ms, and nmr spectroscopy. structural elucidation identified compound 1 as aurasperone a, which, despite successful isolation, showed no antibacterial activity. however, the dcm fraction exhibited moderate inhibition zones against s. aureus (10.08 ± 0.15 mm) and mrsa (10.17 ± 1.17 mm), indicating the presence of other active constituents. in silico adme profiling showed that aurasperone a is highly lipophilic and likely metabolized by cyp1a2, cyp2c19, and cyp2c9 enzymes. target prediction suggested its involvement in ovarian steroidogenesis, regulation of neuronal apoptosis, and adenosine p1 receptor activity. molecular docking revealed strong binding affinities of aurasperone a to human placental aromatase cytochrome p450 (cyp19a1; -9.529 kcal/mol) and aldehyde dehydrogenase (-7.055 kcal/mol), indicating potential roles in hormonal regulation and neuroprotection. molecular dynamics simulations confirmed the stability of the ligand–protein complex, with a free energy value of -39.55 kcal/mol. these findings highlight the pharmacological relevance of aurasperone a beyond antibacterial applications, particularly in hormone-related and neurodegenerative pathways, warranting further biological evaluation.