Waste recovered caffeine as a sustainable corrosion inhibitor and therapeutic lead: A combined DFT, MD & docking approach

This study highlights the dual functionality of caffeine extracted from spent coffee grounds as both a green corrosion inhibitor and a potential broad-spectrum therapeutic agent. Using DFT (B3LYP/6‑311G(d,p)), caffeine exhibited favorable electronic properties (ΔEgap = 4.42 eV, dipole moment = 5.21 D), supporting its strong adsorption capabilities. Molecular Dynamics simulations under acidic conditions confirmed stable, near-flat adsorption on Fe(110), Cu(111), and Al(111) surfaces, with significant interaction energies, indicating robust protective behavior. Simultaneously, molecular docking revealed promising binding affinities of caffeine to SARS-CoV-2 Mpro and Plasmodium falciparum kinases, suggesting antiviral and anti-malarial potential. This theoretical work demonstrates caffeine’s value as a sustainable, multifunctional molecule with applications in both corrosion control and drug discovery.