PGS-IN-1 is a potent inhibitor of prostaglandin synthetase (PGS) with an IC50 of 0.28 μM; also inhibits 5-lipoxygenase with an IC50 of 1.05 μM. IC50 & Target: IC50: 0.28 μM (PGS), 1.05 μM (5-lipoxygenase)In Vitro: The synthesized α-benzulidene-γ-butyrolactones are pure isomers (either cis or trans). PGS-IN-1 is the trans isomer. PGS-IN-1 exhibits potent antiinflammatrory and PGS inhibitory activity (IC50=0.28 μM). PGS-IN-1 also shows potent inhibitory activity against 5-lipoxygenase (IC50=1.05 μM).