Discovery of Dual Target Inhibitors against Cyclooxygenases and Leukotriene A4 Hydrolyase

Dual target inhibitors against COX-2. and LTA(4)H were designed by adding functional groups from a marketed COX-2 inhibitor, Nimesulide, to an existing LTA(4)H inhibitor 1-(2-(4-phenoxyphenoxy) ethyl) pyrrolidine. A series of phenoxyphenyl pyrrolidine compounds were synthesized and tested for their inhibition activities using enzyme assays and human whole blood assay. Introduction of small electron withdrawing groups like NO2 and CF3 in the ortho-position of the terminal phenyl ring was found to change the original single target LTA(4)H inhibitor to dual target LTA(4)H and COX-2 inhibitors. Compound 5a and 5m showed dual LTA(4)H and COX-2 inhibition activities in the enzyme assays and the I-EWE assay with IC50 values in the micromolar to submicromolar range. As their activities in HWB assay were comparable to the two starting single target inhibitors, the two compounds are promising for further studies. The strategy used in the current study may be generally applicable to other dual target drug designs.