Discovery and optimization of 2-thio-5-amino substituted benzoquinones as potent anticancer agents.

Based on our discovered novel lead compound 1 through phenotypic drug discovery (PDD) approaches, systematic structural optimization was performed. A series of 2-allylthio-5-amino substituted benzoquinones were synthesized and evaluated for their in-vitro anticancer activities against human prostate cancer cell line PC3. The compound 7a was found inhibit the growth of PC3 with an IC of 0.22 μM, which is over 20-fold improvement compared to lead compound 1. It is noteworthy that compound 7a also showed potent anti-proliferation activity toward a panel of cancer cells with relatively less cytotoxicity to nonmalignant cell, as well as good water solubility.