Preparation of ligands for lipoxygenase model complexes

ORGN 167

Jerome H. Volkman, volkmanj@ou.edu and Kenneth M. Nicholas, knicholas@ou.edu. Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, OK 73019
We seek to develop catalytic metalloantibody mimics of the lipoxygenase enzymes, which catalyze the selective hydroperoxidation of lipid 1,4-dienes, via C-H activation. The design of the ligands is based by the known geometry of the lipoxygenase enzymes' active site, which includes a tris-imidazole unit with a tethered carboxylic function (R2); a dienyl substrate recognition element is also included (R3). A short and high yielding synthesis of the biologically relevant 4(5)-tris-imidazole ligands has been devised. These ligands possess at the C-2 position of the imidazole ring an open site for further functionalization. Progress of the ongoing effort to functionalize these tripods in order to obtain appropriate tetradentate ligands will be reported.