Copper Complexes as Reactive Oxygen Species Donators Hannah Kiser and Tom E. Bitterwolf Department of Chemistry, University of Idaho, Moscow, ID Synthesis: (PPh 3 ) 3 CuCl + Nuclear Magnetic Resonance (NMR): Structure Confirmation - Low Temperature 31 Phosphorous -Solid State 31 Posphorous and 63 Copper UV-Visibility: Copper Complex + tert-Butyl-SN=O to track RSN=O breakdown to NO. Abstract Background Information Materials and Methods Discussion Conclusion Hypothesis 1. Mani, Katrin, Fang Cheng, et al. "Prion, Amyloid β-derived Cu(II) Ions, or Free Zn(II) Ions Support S-Nitroso-dependent Autocleavage of Glypican-1 Heparan Sulfate." Journal Of Biological Chemistry (2003): Web. 2 Aug Images: journals.prous.com, References Results 1.Copper ions nitrosylate HSPG thiol group 2.Reducing agent oxidizes Cu(II)  Cu(I) 3.Nitric Oxide release 4.Autocatalyzes deaminative cleavage 1 Can we synthesize a model copper compound capable of releasing NO for application of HSPG breakdown and β-amyloid decomposition? Synthesize a copper sulfur bridging compound that will serve as a model nitric oxide donor by breakdown of tert-Butyl-SN=O compound. Alzheimer’s Disease (AD) is characterized by the accumulation of β-amyloid deposits (senile plaques) Amyloid precursor protein (APP) undergoes proteolysis a.P3 Peptide and α-secretase Cu(I) APP  Cu homeostasis regulation, normal process b.β-Amyloid peptide  pathogenic plaques β-amyloid uses Cu +2 and Zn +2 and Heparan Sulfate Proteoglycans (HSPG) to aggregate and form plaques - β- amyloid + Cu(II)  Reactive Oxygen Species, cytotoxic Future Work Continue to synthesize copper complex models for RSNO decomposition Elucidate PPh 3 + RSN=O  PPh 3 =N-S-tBu +PPh 3 O reaction mechanism a. Nitrogen NMR b. Synthesize selenium analog (PPh 3 =NSe-tBu)  77 Se NMR to track intermediates and product growth Our objective was to develop model copper complexes with the ability to decompose a tert-Butyl-SN=O compound and release nitric oxide. We confirmed the structure of our copper complex, (PPh 3 ) 4 Cu 2 S 2 (C 7 H 7 ), with low temperature and solid state NMR techniques. Upon addition of tert-Butyl-SN=O, UV-Visibility studies showed no decomposition; however, low temperature NMR revealed some reaction taking place. While exploring the possible products of the reaction we stumbled upon the reaction PPh 3 + t-Bu-SN=O  PPh 3 S=NR. We took some of the first phosphorous NMR data of the reaction and are currently taking steps to elucidate the reaction mechanism. c.c. a. Free PPh 3 rapidly exchanges at +30 C and overpowers spectrum, as temperature drops exchange slows and two resonances of interest appear. b. Phosphorous coupling with Copper ( 63 Cu and 65 Cu nuclei exhibiting 2:1 abundance ) gives two overlapping quartets. The 63 Cu NMR shows a puzzling two peaks, perhaps two different arrangements of benzyl groups (up-down or both up/down). Free PPh 3    PPh 3 PO Synthesized copper complex, NMR confirmed Cu complex failed to decompose tert-butyl-SNO by UV- Visibility Puzzling NMR data of copper complex + tert-RSNO, lead us to test reaction of PPh 3 + RSNO This reaction produces PPh 3 =NSR and PPh 3 O  First Phosphorous NMR on such reaction  Mechanism of reaction unknown, current research to elucidate! Acknowledgments This publication was made possible by the INBRE Program, NIH Grant Nos. P20 RR (National Center for Research Resources) and P20 GM (National Institute of General Medical Sciences). Thanks to my lab mates for their help and patience and Alex Blumenfeld for NMR data. Confirmed Copper Complex Synthesis by 31 P low temperature and solid state NMR Cu Complex + tert-Butyl- SN=O UV-Visibility: No absorbance peak change, SN=O compound not decomposed to produce NO Low Temperature 31 P NMR: Peak in 0 to -10ppm range disappears, PPh3O peak(17ppm) and unknown 31ppm peak growth  To determine structure of unknown peak perform PPh 3 + tert-Butyl-SN=O reaction and compare NMR PPh3+ tert- Butyl-SN=O Phosphorous NMR: -PPh3=N-S-t-Bu at 19ppm not present in Copper Complex + tert-Butyl-SN=O spectrum Mechanism unknown - We have some of first 31 P NMR data, switch research focus to elucidating reaction mechanism! a. Copper Complex 31 P Low Temperature NMR +30 C, -40 C, -84 C b. Solid State 31 P NMR c. 31 P NMR of Copper Complex + tert-Butyl-SN=O. Phosphine is in equilibrium between free (0 to - 7ppm) and bound (31ppm and 17ppm). The nature of the bound site is not yet clear. d. 31 P NMR of PPh 3 + tert-Butyl-SN=O. Bottom: PPh 3 in D-Toluene. Middle: minutes after addition of tert-Butyl-SN=O. Top: reaction completion, 15 minutes after addition. PPh 3 (- 5ppm) and trace PPh 3 O (25ppm) before addition of SNO. As reaction takes place PPh 3 O peak grows as well as PPh 3 =N-S-t-Bu peak growth (19ppm). d. PPh 3 O   PPh 3 =N-S-t-Bu PPh 3  DecomposedProduced Solid State 63 Cu NMR