Design, synthesis and biological evaluation of piperazino-enaminones as novel suppressants of pro-Inflammatory cytokines

Infection triggers the release of pro-inflammatory cytokines (TNF-alpha and IL-6). Over-production, however, cause tissue injury seen in severe asthma. The ability of enaminone E121 to reduce pro-inflammatory cytokines in our laboratory encouraged further examination of its structural scaffold. Piperazino-enaminones were designed by incorporating n-arylpiperazine motif into the aromatic enaminone. Four possible modifications were explored systematically. Synthesis was accomplished by amination of the corresponding methyl/ethyl 2,4-dioxo-6-(substituted)cyclohexane-carboxylate. Sixteen novel compounds were synthesized. Biological activity was tested in J774 macrophages stimulated with lipopolysaccharides. The release of cytokines was measured via ELISA. Four compounds significantly suppressed TNF-alpha and IL-6 release in dose-dependent manner.