Bioguided isolation of 8-epideoxyloganic acid from Nepeta italica: In vitro and in silico assessments

Abstract

In this study, 8‑epideoxyloganic acid (8‑ELA) was isolated from the methanol fraction of Nepeta italica subsp. italica using a bioactivity‑guided approach. The active NIMFr3 fraction was purified, and the structure of 8‑ELA was elucidated by NMR and MS analyses. The compound exhibited significant inhibitory activity against butyrylcholinesterase (BChE) and α‑glucosidase, with IC₅₀ values of 7.768 ± 0.000 and 3.985 ± 0.066 µg/mL, respectively. Enzyme kinetics revealed a non‑competitive inhibition profile for most enzymes, except lipase. Molecular docking and 100 ns molecular dynamics simulations confirmed stable binding orientations, supported by MM‑PBSA free energy calculations (ΔG_bind = −1.94 kcal/mol). Density functional theory (DFT) analysis indicated a HOMO–LUMO energy gap of 5.660 eV, while PASS prediction suggested potential anti‑inflammatory, antifungal, and metabolic activities. Overall, this work provides complementary in vitro and in silico insights into 8‑ELA, supporting its potential as a candidate molecule for future pharmacological research.

Keywords

• Nepeta italica
• 8-epideoxyloganic acid
• In vitro bioactivity
• In silico studies

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