Isoxazole-5-carboxylic acid derivatives as precursors to hdac6-selective inhibitors

Overview

This research program focuses on the design and synthesis of isoxazole-5-carboxylic acid derivatives intended to serve as precursors for selective inhibitors of histone deacetylase 6 (HDAC6). HDACs are enzymes that regulate gene expression by removing acetyl groups from histone proteins, and aberrant HDAC activity is implicated in cancer, neurodegenerative disorders, and inflammatory diseases. Current HDAC inhibitors often lack selectivity, leading to off-target effects and toxicity. The goal is to develop a new chemical scaffold that selectively targets HDAC6, offering a more precise therapeutic approach.

Technical specifications

The proposed compounds are built around an isoxazole-5-carboxylic acid core, selected for its potential to chelate bivalent metal ions at the active site of HDAC enzymes.

• Metal-binding strategy: The carboxylic acid moiety, and potentially hydroxamic acid derivatives thereof, serves as the metal-chelating group (MBG), a well-established pharmacophore in HDAC inhibitor design.
• Selectivity focus: Structural features are being optimized to favor binding to the HDAC6 isoform over other HDAC family members, potentially reducing off-target effects.
• Chemical rationale: Hydroxamic acids are among the most effective MBGs used in known HDAC inhibitors, and the isoxazole scaffold provides a rigid, tunable platform for medicinal chemistry optimization.

Technology readiness level

This is an early-stage, discovery-phase research program. The hypothesis is grounded in established medicinal chemistry principles regarding metal-chelating pharmacophores for HDAC inhibition, but the specific isoxazole-5-carboxylic acid derivatives have not yet been synthesized or validated. Future work will involve compound synthesis, biochemical assays against HDAC6 and related isoforms, and structure-activity relationship studies to assess selectivity and potency.