Multi-target exploration of newly synthesized pyrazoline-quinoline derivatives via in vitro screening, QSAR, molecular docking, MD simulations, and DFT analysis.

The development of multifunctional therapeutic agents remains a promising strategy in modern drug discovery, particularly for diseases associated with oxidative stress, bacterial infections, and cancer progression. In this study, a new series of [5-(substituted phenyl)-3-(substituted phenyl)-4,5-dihydro-pyrazol-1-yl]-(2-methyl-quinolin-4-yl)-methanones (9a-o) has been synthesized and evaluated for anticancer, antibacterial, and antioxidant activities through established in vitro and in silico screening models. The in vitro cytotoxic evaluation conducted against the human lung cancer cell line (A549) using the MTT assay revealed that all synthesized compounds have significant inhibitory potential. Among them, compounds 9i, 9b, 9h, 9d, and 9o demonstrated superior potency, showing IC₅₀ values of 3.68 ± 0.45 μM, 4.06 ± 0.35 μM, 4.33 ± 0.68 μM, 6.32 ± 0.89 μM, and 7.82 ± 0.52 μM compared to the reference drug doxorubicin, which showed an IC₅₀ of 9.48 ± 0.35 μM under identical experimental conditions. The same compounds also possess the best antibacterial (MIC value 12.5-25 μg/mL) and antioxidant potential. The in silico studies encompassed ADMET analysis, QSAR, molecular docking, and molecular dynamics simulations, which were carried out using Molsoft LLC, pkCSM, ChemDes, AutoDock 4.2, and GROMACS software. Their electronic and reactivity features were also analyzed through DFT calculations based on HOMO, LUMO, electron affinity, ionization potential, chemical potential, and global softness. The results of computational studies reinforced the findings in all dimensions. In summary, this study introduces a promising class of pyrazoline-quinoline conjugates with significant multifunctional efficacy.