Discovery of a simplified deguelin analog as an HSP90 C-terminal inhibitor for HER2-positive breast cancer

A series of O-substituted analogs of the C-ring-truncated scaffold of deguelin designed as heat shock protein 90 (HSP90) C-terminal inhibitors were investigated as novel antitumor agents against human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Among the synthesized compounds, compound 37 displayed significant inhibition in both trastuzumab-sensitive and trastuzumab-resistant breast cancer cells with little cytotoxicity to...