Efficient synthesis of new phenanthridine Wnt/β-catenin signaling pathway agonists.

Previously, HLY78, a lycorine derivative, was identified as the first Wnt/β-catenin signaling agonist through binding to the DAX domain of Axin, a scaffold of Wnt/β-catenin complex. In this study, to obtain more potent Wnt/β-catenin agonist, the structure optimization of HLY78 was carried out by design and synthesis of six phenanthridine derivatives, which afforded five active ones. In particular, 8,9-bis((1,3-dimethyl-1H-pyrazol)methoxy)-5-ethyl-4-methyl-5,6-dihydrophenanthridine showed the most potent activity (0.15/μM) that was increased nearly 30 times as that of the lead HLY78. These compounds may be valuable in future pharmacological or biological studies.