Quinazoline-based dual-target inhibitors disrupt influenza virus RNP complex: Rational design, synthesis and mechanistic validation of potent anti-influenza agents

In this study, we report the rational design and synthesis of 34 novel quinazoline analogs targeting the influenza virus ribonucleoprotein (RNP) complex. These compounds, categorized into four structural classes, were evaluated for anti-influenza activity. Lead compounds 26 and 30 demonstrated potent antiviral efficacy against A/WSN/33(H1N1), with EC₅₀ values of 5.09 ± 0.21 μM and 3.63 ± 0.06 μM, respectively, and high selectivity indices (SI > 19.7 and > 27.5). Surface plasmon resonance (SPR) experiments confirmed dual binding to nucleoprotein (NP; K_D = 6.72 μM for 26, 10.1 μM for 30) and the PA C-terminal domain (PAc; K_D = 3.94 μM for 26, 0.857 μM for 30), key components of the viral RNP complex. Molecular docking and dynamics simulations revealed critical interactions: disruption of the NP Glu339-Arg416 salt bridge (essential for oligomerization) and binding to the PA-PB1 interface (residues Lys643, Glu623, Trp706), destabilizing polymerase assembly. RNP inhibition assays further validated suppression of viral transcription/replication (56.8–68.5 % inhibition at 12.5 μM). Despite favorable potency, solubility optimization remains necessary for improved drug-like properties. By integrating static docking poses with MD-derived dynamic correlations (DCCM), principal component analysis (PCA), and FEL-quantified energy basins, this study revealed transient yet mechanistically vital ligand-protein interaction nodes. This study establishes quinazoline-based dual-targeting inhibitors as promising anti-influenza agents, providing a foundation for further development against resistant strains.