Evaluation of synthetic naphthalene derivatives as novel chemical chaperones that mimic 4-phenylbutyric acid.

The chemical chaperone 4-phenylbutyric acid (4-PBA) has potential as an agent for the treatment of neurodegenerative diseases. However, the requirement of high concentrations warrants chemical optimization for clinical use. In this study, novel naphthalene derivatives with a greater chemical chaperone activity than 4-PBA were synthesized with analogy to the benzene ring. All novel compounds showed chemical chaperone activity, and 2 and 5 possessed high activity. In subsequent experiments, the protective effects of the compounds were examined in Parkinson's disease model cells, and low toxicity of 9 and 11 was related to amphiphilic substitution with naphthalene.

4-Phenylbutyric acid protects against neuronal cell death by primarily acting as a chemical chaperone rather than histone deacetylase inhibitor.

This letter describes the mechanism behind the protective effect of 4-phenylbutyric acid (4-PBA) against endoplasmic reticulum (ER) stress-induced neuronal cell death using three simple 4-(p-substituted phenyl) butyric acids (4-PBA derivatives). Their relative human histone deacetylase (HDAC) inhibitory activities were consistent with a structural model of their binding to HDAC7, and their ability to suppress neuronal cell death and activity of chemical chaperone in vitro. These data suggest that 4-PBA protects against neuronal cell death mediated by the chemical chaperone activity rather than by inhibition of histone deacetylase.