Synthesis, Computational, and In Vitro Evaluation of Pyridine Analogs to Combat Lung Cancer

A novel series of pyridine-based urea derivatives was developed in this thesis as potential inhibitors of EGFR tyrosine kinase, utilizing rational drug design strategies. The study was conducted in four integrated phases, beginning with in silico prediction of ADME (absorption, distribution, metabolism, and excretion) and physicochemical properties. Synthetically, the pyridine core was constructed via a modified Hantzsch reaction, followed by hydrolysis, chlorination, and urea coupling to introduce diverse functionalities. The resulting compounds N,N-dicarbamoyl-4-(3-phenyl)-2,6-dimethyl-4H-1-pyridine-3,5-dicarboxamide derivatives were characterized using IR, NMR, and mass spectrometry, exhibiting melting points between 80 and 156°C and good yields (74–95%). Physicochemical profiling indicated moderate polarity, with hydrogen bond acceptors (4–8), donors (5–7), and molar refractivity (99.77–113.07). Drug-likeness scores ranged from 0.17 to 0.55, indicating some favorable features but underscoring the need for further optimization to enhance oral bioavailability. ADME predictions showed no blood-brain barrier penetration and poor gastrointestinal absorption, characteristics typical of systemic anticancer agents. The compounds were relatively hydrophilic (log P: –0.25 to 1.23), which could limit membrane permeability but reduce off-target effects. Molecular docking against the EGFR kinase domain (PDB: 1M17) using Cresset Flare revealed several compounds with strong binding affinities. Notably, compound N3,N5-dicarbamoyl-4-(3,4-dimethoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamide showed a binding strength close to crizotinib and superior to erlotinib. Biological evaluation via MTT assay on lung cancer cells demonstrated that compounds N3,N5-dicarbamoyl-4-(3,4-dimethoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamide, N3,N5-dicarbamoyl-2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxamide, and especially N3,N5-bis(2-nitrobenzamido)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamide exhibited significant cytotoxicity, with N3,N5-bis(2-nitrobenzamido)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamide being the most potent (IC50 = 10 to 100 μM). At the same time, N3,N5-dicarbamoyl-4-(2-chlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamide and N3,N5-dicarbamoyl-4-(3,4-dihydroxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxamide were inactive.