1-arylsulfonyl-5-(N-hydroxyacrylamide)indolines histone deacetylase inhibitors are potent cytokine release suppressors.

A series of 1-arylsulfonyl-5-(N-hydroxyacrylamide)indolines (7-15) has been developed; the compounds exhibited potent histone deacetylase (HDAC) inhibitory activities. Notably, almost all of this series exhibited better HDAC-inhibitory and antiproliferative activities than 3-(1-benzenesulfonyl-1H-indol-5-yl)-N-hydroxyacrylamide (6), as reported in a previous study. Among these compounds, 3-[1-(4-methoxybenzenesulfonyl)-2,3-dihydro-1H-indol-5-yl]-N-hydroxyacrylamide (9) showed a two- to tenfold increase in activity compared to SAHA (1) in the suppression of lipopolysaccharide-induced cytokine production. Compound 9 also caused a marked reduction in carrageenan-induced acute inflammation in a rat model. Taken together, these data indicated that 1-arylsulfonyl-5-(N-hydroxyacrylamide)indolines HDAC inhibitors exhibit potent anti-inflammatory activity.