title: Synthesis and photophysical characterisation of new fluorescent triazole adenine analogues.
abstract: Fluorescent nucleic acid base analogues are powerful probes of DNA structure. Here we describe the synthesis and photo-physical characterisation of a series of 2-(4-amino-5-(1H-1,2,3-triazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl) and 2-(4-amino-3-(1H-1,2,3-triazol-4-yl)-1H-pyrazolo[3,4-d]pyrimidin-1-yl) analogues via Sonogashira cross-coupling and [3 + 2]-cycloaddition reactions as the key steps in the synthesis. Compounds with a nitrogen atom in position 8 showed an approximately ten-fold increase in quantum yield and decreased Stokes shift compared to analogues with a carbon atom in position 8. Furthermore, the analogues containing nitrogen in the 8-position showed a more red-shifted and structured absorption as opposed to those which have a carbon incorporated in the same position. Compared to the previously characterised C8-triazole modified adenine, the emissive potential was significantly lower (tenfold or more) for this new family of triazoles-adenine compounds. However, three of the compounds have photophysical properties which will make them interesting to monitor inside DNA.
authors.affiliation: Department of Chemistry, Medicinal Chemistry, University of Gothenburg, S-41296 Gothenburg, Sweden. grotli@chem.gu.se.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Lawson
authors.forename: Anke
authors.initials: A
authors.lastname: Dierckx
authors.forename: Francois-Alexandre
authors.initials: FA
authors.lastname: Miannay
authors.forename: Eric
authors.initials: E
authors.lastname: Wellner
authors.forename: L Marcus
authors.initials: LM
authors.lastname: Wilhelmsson
authors.forename: Morten
authors.initials: M
authors.lastname: Grøtli
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D004247:DNA / Q000032:analysis / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011789:Quantum Theory; D013050:Spectrometry, Fluorescence; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D014230:Triazoles; D004247:DNA; D000225:Adenine