Ripon College1, Chemistry Department, Ripon, WI 54971 University of Colorado2, Department of Pediatrics, Aurora, CO 80045
SYNTHESIS AND PURIFICATION OF BROMINATED UBIQINONE PSEUDOSUBTRATES FOR ELECTRON-TRANSFER FLAVOPROTEIN: UBIQUINONE OXIDOREDUCTASE (ETF:QO) Andrea K. Furdek, W. W. Radford, C. M. Byron*1, F. E.Frerman2 , Ripon College, Department of Chemistry, Ripon, WI 54971, byronc@ripon.edu 1, Department of Pediatrics, University of Colorado Health Sciences Center, Aurora, CO 80045 2
Ubiquinone (Co-Q) is an important electron carrier in the electron transport chain located in the inner mitochondrial membrane. The sixth position of this quinone naturally has 10 consecutive isoprene units. In our studies, the sixth position was modified to contain straight chain methylene groups terminating in a bromine similarly to the methods of C.-A. Yu and L. Yu (Biochemistry 1982, 21, 4096-4101). In the organic synthesis of these straight chain Co-Q derivatives, terminally monobrominated acid chlorides or carboxylic acids were converted to brominated peroxy-acids and joined to the sixth position of 2,3-dimethoxy-5-methyl-1,4-benzoquinone (Q0). The chain lengths synthesized had 3,4,5,9,10,and 15 methylene units and were termed Q3Br through Q15Br. Product purification was originally achieved with a florisil gel chromatography column. Preparatory-TLC was found to be a more efficient method of purification. NMR spectra and analytical TLC confirmed the products. These brominated ubiquinones were then used for fluorescence quenching studies with the human form of ETF:QO.
[Abstract (DOC)]