The synthesis of novel 1-thio-substituted butadienes, designed as mechanism-based 5- lipoxygenase inhibitors, is described. The structure of these compounds closely resembles a proposed high-energy intermediate during the lipoxygenation of arachidonic acid. They demonstrate 5-lipoxygenase inhibition in vitro and in vivo. The most potent compound is 15a with an ICx, of 1.8 pM in vitro. LTCl release was inhibited by 80% after intraperitoneal ...