title: A relationship between amide hydrogen bond strength and quinone reduction potential: implications for photosystem I and bacterial reaction center quinone function.
abstract: A series of 11 simple phylloquinone derivatives, each lacking the extended phytyl side chain but featuring H-bond donor amides at one or both peri positions, were prepared and some salient physical properties were measured. A correlation between both IR frequency and NMR peak position, as indicators of internal H-bond strength, and the quinone half-wave reduction potential, was observed. These data are consistent with the prevailing hypothesis that quinone carbonyl H-bonding in general, and stronger H-bonds in particular, favorably bias the endogenous quinone's electrochemical potential toward easier reduction.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA. ksf@chem.psu.edu
authors.forename: Ken S
authors.initials: KS
authors.lastname: Feldman
authors.forename: D Keith
authors.initials: DK
authors.lastname: Hester
authors.forename: John H
authors.initials: JH
authors.lastname: Golbeck
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D015195:Drug Design; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008968:Molecular Conformation; D009285:Naphthoquinones / Q000737:chemistry; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D045331:Photosystem I Protein Complex / Q000378:metabolism*; D011809:Quinones / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D009285:Naphthoquinones; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D011809:Quinones