Ying-Ju Hou, Mica Grantham, Dr. Sharon J. N. Burgmayer
Department of Chemistry
Bryn Mawr College
Bryn Mawr, PA 19010
Synthesis of Molybdopterin Bis-Dithiolenes as Model Compounds for the Molybdenum Cofactor
Molybdenum and tungsten enzymes are present in nearly all biological systems and are involved in the metabolism of sulfur, nitrogen and carbon. All molybdenum-oxo enzymes, with the exception of nitrogenase, contain the molybdenum cofactor, Moco, which contains a molybdopterin ligand at a mononuclear Mo atom. In the active site, Moco participates in both oxygen atom and proton-electron transfer processes. Molybdopterin bis-dithiolenes serve to model structure, reactivity and spectroscopy for Moco in one class of enzymes. In this research group, the organic ligand precursors, phenylethynyl pivaloyl pterin (PEPP) and difluorophenylethynyl pivaloyl pterin (diFPEPP) are reacted with TEA2MoOS8 and TEA2MoS9 to produce the molybdopterin bis-dithiolene complexes, TEA2MoO(S2PEPP)2, TEA2MoO(S2diFPEPP)2, TEA2MoS(S2PEPP)2, and TEA2MoS(S2diFPEPP)2. Results of characterization by IR, NMR and ESI-MS to date suggest the formation of bis-dithiolene complexes.