Synthesis and biological evaluation of piperlongumine derivatives as potent anti-inflammatory agents

Piperlongumine (PL) and its derivatives were synthesized by the direct reaction between acid chloride of 3,4,5-trimethoxycinnamic acid and various amides/lactams. Later their anti-inflammatory effects were evaluated in lipopolysaccharide (LPS)-induced RAW-264.7 macrophages. Of the piperlogs prepared in this study, the maximum (91%) inhibitory activity was observed with PL (IC50 = 3 mu M) but showed cytotoxicity whereas compound 3 (IC50 = 6 mu M) which possess alpha,beta-unsaturated gamma-butyrolactam moiety offered good level (65%) of activity with no cytotoxicity. This study revealed that amide/lactam moiety connected to cinnamoyl group with minimum 3 carbon chain length and alpha,beta-unsaturation is fruitful to show potent anti-inflammatory activity. (C) 2014 Elsevier Ltd. All rights reserved.