Synthesis, Biological Evaluation, and Autophagy Mechanism of 12 N-Substituted Sophoridinamines as Novel Anticancer Agents

A series of 12N-substituted sophoridinamine derivatives were synthesized and evaluated for their cytotoxic activities in human HepG2 hepatoma cells. Structure-activity relationship revealed that introduction of a suitable arylidene or arylethyl at the N'-end could greatly enhance antiproliferation potency. Among them, compound 6b possessing a N'-trimethoxyphenyl methylene exhibited potent antiproliferation effect against three human tumor cell lines including HepG2, leukemia (K562), and breast Cancer (HMLE), with IC₅₀ between 0.55 and 1.7 μM. The underlying mechanism of 6b against tumor cells is to block autophagic flux, mainly through neutralizing lysosomal acidity. Our results indicated that compound 6b is a potent lysosomal deacidification agent and is accordingly able to block autophagic flux and inhibit tumor cell growth.

Sophoridinamine; anticancer; autophagy; lysosomes; structure−activity relationship.