Discovery of sp3-rich diazatricycloundecanes as lysosomotropic autophagy inhibitors

We have discovered lysosomotropic autophagy inhibitors from our compound library of sp³-rich diazatricycloundecane skeletons. Compound 1u was identified as the most potent biological activity for LC3-II protein accumulation through the structure-activity relationships (SARs) for LC3-II protein accumulation and anti-proliferative activity at the three freely available substituents (R¹-R³) in the diazatricycloundecane skeleton. Compound 1u inhibited lysosome-dependent degradation without affecting autophagosome formation. Furthermore, compound 1u enlarged lysosomes and raised lysosomal pH similar to lysosomotropic agents such as chloroquine, resulting in inhibiting late-stage autophagy by inducing lysosomal dysfunction. Moreover, compound 1u exhibits excellent drug-like chemical properties, not previously reported for lysosomotropic agents.