Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA

There has been much effort to exploit fluorescence techniques in the detection of nucleic acids. Canonical nucleic acids are essentially nonfluorescent; however, the modification of the nucleobase has proved to be a fruitful way to engender fluorescence. Much of the chemistry used to prepare modifie...

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Main Authors: Ali Heidari, Arash Ghorbani-Choghamarani, Maryam Hajjami, Robert H. E. Hudson
Format: Article
Language:English
Published: MDPI AG 2020-04-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/25/8/1995
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author Ali Heidari
Arash Ghorbani-Choghamarani
Maryam Hajjami
Robert H. E. Hudson
author_facet Ali Heidari
Arash Ghorbani-Choghamarani
Maryam Hajjami
Robert H. E. Hudson
author_sort Ali Heidari
collection DOAJ
description There has been much effort to exploit fluorescence techniques in the detection of nucleic acids. Canonical nucleic acids are essentially nonfluorescent; however, the modification of the nucleobase has proved to be a fruitful way to engender fluorescence. Much of the chemistry used to prepare modified nucleobases relies on expensive transition metal catalysts. In this work, we describe the synthesis of biaryl quinazolinone-uracil nucleobase analogs prepared by the condensation of anthranilamide derivatives and 5-formyluracil using inexpensive copper salts. A selection of modified nucleobases were prepared, and the effect of methoxy- or nitro- group substitution on the photophysical properties was examined. Both the dihydroquinazolinone and quinazolinone modified uracils have much larger molar absorptivity (~4–8×) than natural uracil and produce modest blue fluorescence. The quinazolinone-modified uracils display higher quantum yields than the corresponding dihydroquinazolinones and also show temperature and viscosity dependent emission consistent with molecular rotor behavior. Peptide nucleic acid (PNA) monomers possessing quinazolinone modified uracils were prepared and incorporated into oligomers. In the sequence context examined, the nitro-substituted, methoxy-substituted and unmodified quinazolinone inserts resulted in a stabilization (∆T<sub>m</sub> = +4.0/insert; +2.0/insert; +1.0/insert, respectively) relative to control PNA sequence upon hybridization to complementary DNA. All three derivatives responded to hybridization by the “turn-on” of fluorescence intensity by ca. 3-to-4 fold and may find use as probes for complementary DNA sequences.
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spelling doaj.art-fca7fc78b261431c8b13ecf7ba680c912023-11-19T22:33:52ZengMDPI AGMolecules1420-30492020-04-01258199510.3390/molecules25081995Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNAAli Heidari0Arash Ghorbani-Choghamarani1Maryam Hajjami2Robert H. E. Hudson3Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, CanadaDepartment of Chemistry, Faculty of Science, Ilam University, Ilam 69315516, IranDepartment of Chemistry, Faculty of Science, Ilam University, Ilam 69315516, IranDepartment of Chemistry, The University of Western Ontario, London, ON N6A 5B7, CanadaThere has been much effort to exploit fluorescence techniques in the detection of nucleic acids. Canonical nucleic acids are essentially nonfluorescent; however, the modification of the nucleobase has proved to be a fruitful way to engender fluorescence. Much of the chemistry used to prepare modified nucleobases relies on expensive transition metal catalysts. In this work, we describe the synthesis of biaryl quinazolinone-uracil nucleobase analogs prepared by the condensation of anthranilamide derivatives and 5-formyluracil using inexpensive copper salts. A selection of modified nucleobases were prepared, and the effect of methoxy- or nitro- group substitution on the photophysical properties was examined. Both the dihydroquinazolinone and quinazolinone modified uracils have much larger molar absorptivity (~4–8×) than natural uracil and produce modest blue fluorescence. The quinazolinone-modified uracils display higher quantum yields than the corresponding dihydroquinazolinones and also show temperature and viscosity dependent emission consistent with molecular rotor behavior. Peptide nucleic acid (PNA) monomers possessing quinazolinone modified uracils were prepared and incorporated into oligomers. In the sequence context examined, the nitro-substituted, methoxy-substituted and unmodified quinazolinone inserts resulted in a stabilization (∆T<sub>m</sub> = +4.0/insert; +2.0/insert; +1.0/insert, respectively) relative to control PNA sequence upon hybridization to complementary DNA. All three derivatives responded to hybridization by the “turn-on” of fluorescence intensity by ca. 3-to-4 fold and may find use as probes for complementary DNA sequences.https://www.mdpi.com/1420-3049/25/8/1995peptide nucleic acidnucleobase-modified PNAsolid-phase synthesisdihydroquinazolinonequinazolinonequinazolinone based nucleobase
spellingShingle Ali Heidari
Arash Ghorbani-Choghamarani
Maryam Hajjami
Robert H. E. Hudson
Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA
Molecules
peptide nucleic acid
nucleobase-modified PNA
solid-phase synthesis
dihydroquinazolinone
quinazolinone
quinazolinone based nucleobase
title Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA
title_full Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA
title_fullStr Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA
title_full_unstemmed Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA
title_short Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA
title_sort fluorescent biaryl uracils with c5 dihydro and quinazolinone heterocyclic appendages in pna
topic peptide nucleic acid
nucleobase-modified PNA
solid-phase synthesis
dihydroquinazolinone
quinazolinone
quinazolinone based nucleobase
url https://www.mdpi.com/1420-3049/25/8/1995
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AT maryamhajjami fluorescentbiaryluracilswithc5dihydroandquinazolinoneheterocyclicappendagesinpna
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