title: Monitoring guanine photo-oxidation by enantiomerically resolved Ru(II) dipyridophenazine complexes using inosine-substituted oligonucleotides.
abstract: The intercalating [Ru(TAP)2(dppz)](2+) complex can photo-oxidise guanine in DNA, although in mixed-sequence DNA it can be difficult to understand the precise mechanism due to uncertainties in where and how the complex is bound. Replacement of guanine with the less oxidisable inosine (I) base can be used to understand the mechanism of electron transfer (ET). Here the ET has been compared for both Λ- and Δ-enantiomers of [Ru(TAP)2(dppz)](2+) in a set of sequences where guanines in the readily oxidisable GG step in {TCGGCGCCGA}2 have been replaced with I. The ET has been monitored using picosecond and nanosecond transient absorption and picosecond time-resolved IR spectroscopy. In both cases inosine replacement leads to a diminished yield, but the trends are strikingly different for Λ- and Δ-complexes.
authors.affiliation: School of Chemistry, Trinity College, Dublin 2, Ireland. keanepa@tcd.ie jmkelly@tcd.ie and Dept. of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK. c.j.cardin@rdg.ac.uk.
authors.forename: Páraic M
authors.initials: PM
authors.lastname: Keane
authors.affiliation: School of Chemistry, Trinity College, Dublin 2, Ireland. keanepa@tcd.ie jmkelly@tcd.ie and Trinity Biomedical Sciences Institute, Dublin 2, Ireland.
authors.forename: Fergus E
authors.initials: FE
authors.lastname: Poynton
authors.affiliation: Dept. of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK. c.j.cardin@rdg.ac.uk and Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0QX, UK.
authors.forename: James P
authors.initials: JP
authors.lastname: Hall
authors.affiliation: Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxfordshire OX11 0QX, UK.
authors.forename: Ian P
authors.initials: IP
authors.lastname: Clark
authors.affiliation: Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxfordshire OX11 0QX, UK.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Sazanovich
authors.affiliation: Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxfordshire OX11 0QX, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Towrie
authors.affiliation: School of Chemistry, Trinity College, Dublin 2, Ireland. keanepa@tcd.ie jmkelly@tcd.ie and Trinity Biomedical Sciences Institute, Dublin 2, Ireland.
authors.forename: Thorfinnur
authors.initials: T
authors.lastname: Gunnlaugsson
authors.affiliation: School of Chemistry, University College Dublin, Dublin 4, Ireland.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Quinn
authors.affiliation: Dept. of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK. c.j.cardin@rdg.ac.uk.
authors.forename: Christine J
authors.initials: CJ
authors.lastname: Cardin
authors.affiliation: School of Chemistry, Trinity College, Dublin 2, Ireland. keanepa@tcd.ie jmkelly@tcd.ie.
authors.forename: John M
authors.initials: JM
authors.lastname: Kelly
mesh_terms: D006147:Guanine / Q000032:analysis / Q000737:chemistry*; D007288:Inosine / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D010777:Photochemistry; D012428:Ruthenium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D009841:Oligonucleotides; D009942:Organometallic Compounds; C483523:ruthenium dipyridophenazine; D007288:Inosine; D006147:Guanine; D012428:Ruthenium