Decoding the anti-adenoviral potential of Ocimum volatile organic compounds: linking chemical fingerprints to molecular targets via docking

Ocimum species are globally recognized for their pharmaceutical utility, yet a comparative mapping of their volatile architecture against viral pathogens remains incomplete. This study evaluated the chemical profiles and antiadenoviral (ADV) potential of Ocimum basilicum (Local), O. basilicum var. minimum (French), and O. africanum (Kafory). Volatiles from three extraction techniques; hydrodistillation, n -hexane, and headspace—were analyzed via GC/MS. One hundred fifty-seven compounds were quantified and subjected to Principal Component Analysis (PCA) and clustered heat mapping. Biological efficacy was assessed via IC 50 determination, supported by molecular docking and molecular dynamics (MD) simulations. PCA effectively discriminated against species, with PC1 and PC2 accounting for 88% of total variance. Oxygenated monoterpenes emerged as the dominant class. Notably, O. africanum hydrodistilled oil exhibited exceptional antiadenoviral potency (IC 50 of 1.72 µ g/ml), significantly outperforming the French (IC 50 of 54.26 µ g/ml) and Local varieties. This superior activity is hypothesized to be linked to the high relative abundance of methyl cinnamate and cadinol, while in silico molecular docking predicted 1,3-dimethyladamantane as a key potential bioactive candidate. MD trajectories (RMSD, RMSF, Rg, and SASA) support the hypothesis that this ligand forms a stable, rigid complex with the viral protein, effectively reducing structural flexibility. This study establishes a high-resolution chemical-to-biological workflow for Ocimum validation. By identifying a high-potency lead with a predicted binding mechanism, these findings move Ocimum from traditional usage into evidence-based antiviral drug discovery. These results provide a strategic blueprint for developing standardized, plant-derived therapeutics against adenoviral infections.