A Quantum-Mechanical Method Reveals the Potential Basis of Antioxidant Activities of Phytomolecules from Jasminum Species: Isolation, Spectral Characterization, DFT, and In Vitro Studies

Objective: This study aims to identify and characterize secondary metabolites from the leaves of Jasminum sambac and Jasminum grandiflorum, focusing on their bioactive compounds and antioxidant potential. Methods: Ethanolic extracts of Jasminum sambac and Jasminum grandiflorum were used to isolate secondary metabolites ((JG-3–JG-5), (JS-3–JS-5)). These compounds were characterized using IR, NMR, and mass spectrometry. Density functional theory (DFT) was applied to analyze their antioxidant potential through electronic properties (HOMO–LUMO gaps and molecular electrostatic potential). Results and Discussion: Six compounds ((JG-3–JG-5), (JS-3–JS-5)) were successfully isolated and characterized. The DFT analysis revealed potential antioxidant properties based on HOMO–LUMO gaps and MEP maps. The study enhances the knowledge of the secondary metabolites of Jasminum sambac and Jasminum grandiflorum. Computational analysis supports the antioxidant activity of the isolated compounds, suggesting their therapeutic potential and use as quality control markers. Conclusions: Six bioactive compounds were identified and characterized, providing insights into their antioxidant potential and offering opportunities for further pharmacological investigation.