Synthesis of a Tetronic Acid Library Focused on Inhibitors of Tyrosine and Dual-Specificity Protein Phosphatases and Its Evaluation Regarding VHR and Cdc25B Inhibition

Selective inhibitors of protein tyrosine phosphatases (PTPs) and dual-specificity phosphatases (DSPs) are expected to be useful tools for clarifying the biological functions of the PTPs themselves and also to be candidates for novel therapeutics. We planned a library approach for the identification of PTP/DSP inhibitors in which 3-acyltetronic acid is used as a "core" phosphate mimic. A series of novel tetronic acid derivatives were synthesized and evaluated as inhibitors of the dual-specificity protein phosphatases VHR and cdc25B. Several compounds are found to be potent inhibitors of cdc25B, which is a key enzyme for cell-cycle progression. The promising results described herein strongly indicated that this tetronic acid library is potent as a library focused on the PTP/DSP-selective inhibitor.