Biflavonoid compounds have demonstrated significant potential as anticancer agents, particularly as non-covalent proteasome inhibitors. However, the inhibitory mechanisms of these compounds remain underexplored. The 20S proteasome, a key target in cancer therapy, plays a crucial role in protein degradation and cell cycle regulation, making its inhibition a promising strategy for cancer treatment. This study employs an integrated computational approach, combining Three-Dimensional Quantitative Structure-Activity Relationships (3D-QSAR) modelling, molecular docking, molecular dynamics (MD) simulations, and Molecular Mechanics-Generalized Born and Surface Area Solvation (MM/GBSA) binding energy calculations, to evaluate the proteasome inhibitory potential of biflavonoids from the genus Araucaria. A 3D-QSAR model was developed using 62 flavonoid derivatives, with the Partial Least Squares (PLS) model highlighting electrostatic interactions and hydrogen bond donors as key determinants of proteasome inhibition. Concurrently, the Support Vector Machine (SVM) model exhibited superior predictive accuracy (with an R² of 0.98 and a predicted R² of 0.75) and was employed to screen 22 biflavonoid compounds, identifying five candidates with the highest predicted IC50 values: 7-O-methylagathisflavone (1), 7-O-methylcupressuflavone (15), ochnaflavone (22), 7''-O-methylamentoflavone (11), and 7''-O-methylagathisflavone (2). Molecular docking analysis confirmed strong binding affinities of all five compounds within the β5 active site of the 20S proteasome, with 22 exhibiting the highest docking score. However, MD simulations (100 ns) provided a more comprehensive assessment of binding stability, revealing that 1 showed the most stable behaviour, characterized by low RMSD fluctuations, minimal RMSF values, and a stable radius of gyration (Rg). Conversely, 15 and 22 demonstrated substantial conformational fluctuations, indicating diminished long-term stability. MM/GBSA binding energy calculations further substantiated the ranking observed in 3D-QSAR predictions, underscoring the preeminent potential of compound 1 as a promising inhibitor, as it demonstrated the best IC50 prediction, the strongest binding interactions, and the highest dynamic stability. The integration of 3D-QSAR modelling, docking, and MD simulations provides a comprehensive evaluation of biflavonoid-proteasome interactions, offering valuable insights for developing novel anticancer proteasome inhibitors.
The authors are grateful to the Indonesian Ministry of Education, Culture, Research, and Technology through IPB University under Project No. 102/E5/PG.02.00.PL/2023, dated June 19, 2023.
Primary Language | English |
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Subjects | Chemical Thermodynamics and Energetics |
Journal Section | Research Article |
Authors | |
Early Pub Date | May 7, 2025 |
Publication Date | |
Submission Date | December 12, 2024 |
Acceptance Date | March 4, 2025 |
Published in Issue | Year 2026 Volume: 10 Issue: 1 |
Journal Full Title: Turkish Computational and Theoretical Chemistry
Journal Abbreviated Title: Turkish Comp Theo Chem (TC&TC)