Discovery of novel 2-azabicyclo[3.2.1]octane derivatives against non-small cell lung cancer from aconitine simplification.

Aconitine, a diterpenoid alkaloid, exhibits promising bioactivities, but its clinical application is limited by severe toxicity. Through a structural simplification and derivatization strategy, we designed and synthesized a novel series of 2-azabicyclo[3.2.1]octane derivatives. This effort culminated in the identification of compound 8q, which demonstrated potent and selective anti-tumor efficacy against ALK (anaplastic lymphoma kinase) -positive cancer cells (NCI-H2228 and Karpas-299), significantly outperforming ceritinib in enzymatic and cellular assays. Mechanism studies revealed that 8q effectively inhibits ALK phosphorylation and its downstream PI3K/AKT/mTOR and RAS/MEK/ERK signaling pathways, inducing G0/G1 phase cell cycle arrest and apoptosis. Moreover, 8q markedly suppressed cancer cell migration and invasion. In an NCI-H2228 xenograft model, 8q exhibited dose-dependent tumor growth inhibition, with the high-dose group (60 mg/kg) showing superior efficacy to ceritinib (30 mg/kg) and no significant systemic or organ toxicity. Molecular docking and dynamics simulations revealed that 8q stably binds within the ATP-binding pocket of ALK, forming key interactions with residues in the hinge (Glu1197) and solvent-front (Glu1269 and Asp1270) regions. The RMSD and RMSF analyses confirmed enhanced conformational stability of the 8q-ALK complex compared to the apo protein. Collectively, these findings highlight 8q as a promising lead compound for the development of novel ALK inhibitors with a favorable efficacy and safety profile.