As a typical dibenzylisoquinoline
alkaloid,
tetrandrine (TET) is clinically used for the treatment of
silicosis, inflammatory pulmonary, and
cardiovascular diseases in China. Recent investigations have demonstrated the outstanding anticancer activity of this structure, but its poor aqueous solubility severely restricts its further development. Herein, a series of its 14-N-amino
acid-substituted derivatives with improved anticancer effects and aqueous solubility were designed and synthesized. Among them, compound 16 displayed the best antiproliferative activity against human
colorectal cancer (HCT-15) cells, with an IC50 value of 0.57 μM. Compared with TET, 16 was markedly improved in terms of aqueous solubility (by 5-fold). Compound 16 significantly suppressed the colony formation, migration, and invasion of HCT-15 cells in a concentration-dependent manner, with it being more potent in this respect than TET. Additionally, compound 16 markedly impaired the morphology and motility of HCT-15 cells and induced the death of
colorectal cancer cells in double-staining and flow cytometry assays. Western blot results revealed that 16 could induce the autophagy of HCT-15 cells by significantly decreasing the content of p62/SQSTM1 and enhancing the
Beclin-1 level and the ratio of LC3-II to LC3-I. Further study showed that 16 effectively inhibited the proliferation, migration, and tube formation of umbilical vein endothelial cells, manifesting in a potent
anti-angiogenesis effect. Overall, these results revealed the potential of 16 as a promising candidate for further preclinical studies.