NDLI: The solvent effect and identification of a weakly emissive state in nonradiative dynamics of guanine nucleosides and nucleotides--a combined femtosecond broadband time-resolved fluorescence and transient absorption study.

Please wait, while we are loading the content...

The solvent effect and identification of a weakly emissive state in nonradiative dynamics of guanine nucleosides and nucleotides--a combined femtosecond broadband time-resolved fluorescence and transient absorption study.

Electronic coupling between photo-excited stacked bases in DNA and RNA strands with emphasis on the bright states initially populated.

Sensitized photochemistry of di(4-tetrazolouracil) dinucleoside monophosphate as a route to dicytosine cyclobutane photoproduct precursors.

The variety of UV-induced pyrimidine dimeric photoproducts in DNA as shown by chromatographic quantification methods.

A joint experimental/theoretical study of the ultrafast excited state deactivation of deoxyadenosine and 9-methyladenine in water and acetonitrile.

Photochemistry and photophysics of the amino and imino tautomers of 1-methylcytosine: tautomerisation as a side product of the radiationless decay.

The photoinduced transformation of fluorescent DNA base analogue tC triggers DNA melting

Strong impact of the solvent on the photokinetics of a 2(1H)-pyrimidinone.

Electronic excited states of guanine-cytosine hairpins and duplexes studied by fluorescence spectroscopy.

Electronic excitation and structural relaxation of the adenine dinucleotide in gas phase and solution.

Photophysical properties of 5-substituted 2-thiopyrimidines.

Ultrafast electronic deactivation dynamics of the inosine dimer--a model case for H-bonded purine bases.

Accumulation of the cyclobutane thymine dimer in defined sequences of free and nucleosomal DNA.

The relative roles of DNA damage induced by UVA irradiation in human cells.

The effect of dimerization on the excited state behavior of methylated xanthine derivatives: a computational study.

UV-induced formation of the thymine-thymine pyrimidine (6-4) pyrimidone photoproduct--a DFT study of the oxetane intermediate ring opening.

Role of intercalation and redox potential in DNA photosensitization by ruthenium(II) polypyridyl complexes: assessment using DNA repair protein tests.

The interplay between neutral exciton and charge transfer states in single-strand polyadenine: a quantum dynamical investigation.

Interaction of UV radiation with DNA.

Cytosine containing dipyrimidine sites can be hotspots of cyclobutane pyrimidine dimer formation after UVB exposure.

Year: 2013 Volume: 12 Issue: 7

Year: 2013 Volume: 12 Issue: 6

Year: 2013 Volume: 12 Issue: 5

Year: 2013 Volume: 12 Issue: 4

Year: 2013 Volume: 12 Issue: 3

Year: 2013 Volume: 12 Issue: 2

Year: 2013 Volume: 12 Issue: 1

Year: 2012 Volume: 11

Year: 2011 Volume: 10

The solvent effect and identification of a weakly emissive state in nonradiative dynamics of guanine nucleosides and nucleotides--a combined femtosecond broadband time-resolved fluorescence and transient absorption study.

Content Provider	World Health Organization (WHO)-Global Index Medicus
Author	Cheng, Chopen Chan-Wut Ma, Chensheng Chan, Chris Tsz-Leung Ho, Keith Yat-Fung Kwok, Wai-Ming
Description	Country affiliation: China Author Affiliation: Cheng CC ( Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.)
Abstract	A combined method of femtosecond broadband time-resolved fluorescence (fs-TRF) and transient absorption (fs-TA) was employed to investigate the excited state dynamics of 2'-deoxyguanosine (dG) and 2'-deoxyguanosine 5'-monophosphate (dGMP). Comparative fs-TRF and fs-TA measurements were conducted on dG and dGMP in neutral water, deuterated water, and methanol with excitation wavelengths of 245, 267 and 285 nm. Very similar results were observed with dG and dGMP. The data provide compelling evidence for the co-existence of two nonradiative pathways. One is the generally recognized Laππ* mediated channel, the other involves an unprecedented weakly emissive state which plays a significant role in the overall deactivation processes. The Laππ* channel features biphasic dynamics with time constants (τ1/τ2) of ~0.2/0.8 ps in water and ~0.25/1.0 ps in methanol. The biphasic decay arises due to a partial transfer with τ1 of the Laππ* population to the newly identified state followed by conversion in τ2 of the remaining Laππ* molecules into the electronic ground state. The channel mediated by the weakly emissive species shows solvent-dependent dynamics with time constants (τ3) of ~2.0 ps in water, ~2.3 ps in deuterated water, and ~4.1 ps in methanol. The species features absorption at UV wavelengths (~300-400 nm) and exhibits deeply red-shifted fluorescence (λmax ~ 520 nm) with polarization direction varied markedly from that of the Laππ* but close to the Lbππ. This species acts as an effective quenching state to the radiative decay of the brightly emissive Laππ and Lbππ. It sets in promptly (<~50 fs) after the photoexcitation and is further populated through nonadiabatic coupling with the Laππ. The overall involvement of this state is facilitated with excitation at high energy and is favoured in methanol over water. According to the spectral character and the solvent effect in particular the kinetic isotope effect, the species is tentatively associated to the πσ* state with charge transfer (CT) character which is considered to be preferentially stabilized by hydrogen-bonding between the guanine amino and surrounding solvent molecules. The result of this study leads to a dramatically different picture of guanine deactivation. It demonstrates a crucial role of the solvent in shaping the nonradiative dynamics of guanine nucleosides and nucleotides. The data presented are important for understanding the detailed photophysics of not only the monomeric guanine but also DNA assemblies that contain guanine in base pairs or have a guanine tetrad as the structural motif.
File Format	HTM / HTML
ISSN	1474905X
Issue Number	8
Volume Number	12
e-ISSN	14749092
Journal	Photochemical & Photobiological Sciences
Language	English
Publisher	Royal Society of Chemistry
Publisher Date	2013-08-01
Publisher Place	Great Britain (UK)
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Discipline Chemistry Discipline Biology Deoxyguanine Nucleotides Chemistry Deoxyguanosine Fluorescence Methanol Solvents Spectrometry, Fluorescence Methods Water Journal Article Research Support, Non-u.s. Gov't
Content Type	Text
Resource Type	Article
Subject	Physical and Theoretical Chemistry

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Excited-State Dynamics of dGMP Measured by Steady-State and Femtosecond Fluorescence $Spectroscopy^{†}$

Water-Soluble Single-Benzene Chromophores: Excited State Dynamics and Fluorescence Detection

Solvent-induced multicolour fluorescence of amino-substituted 2,3-naphthalimides studied by fluorescence and transient absorption measurements

Solvent effect on the absorption and fluorescence of ergone: determination of ground and excited state dipole moments.

Excited State Relaxation of Neutral and Basic 8-Oxoguanine

Ultrafast Photochemistry of Copper(II) Monochlorocomplexes in Methanol and Acetonitrile by Broadband Deep-UV-to-Near-IR Femtosecond Transient Absorption Spectroscopy.

A tabletop femtosecond time-resolved soft x-ray transient absorption spectrometer.

Effect of Solvent Hydrogen Bonding on Excited-State Properties of Luminol: A Combined Fluorescence and DFT Study

Solvent effects on excitation relaxation dynamics of a keto-carotenoid, siphonaxanthin.

The solvent effect and identification of a weakly emissive state in nonradiative dynamics of guanine nucleosides and nucleotides--a combined femtosecond broadband time-resolved fluorescence and transient absorption study.

Similar Documents

Excited-State Dynamics of dGMP Measured by Steady-State and Femtosecond Fluorescence $Spectroscopy^{†}$

Water-Soluble Single-Benzene Chromophores: Excited State Dynamics and Fluorescence Detection

Solvent-induced multicolour fluorescence of amino-substituted 2,3-naphthalimides studied by fluorescence and transient absorption measurements

Solvent effect on the absorption and fluorescence of ergone: determination of ground and excited state dipole moments.

Excited State Relaxation of Neutral and Basic 8-Oxoguanine

Ultrafast Photochemistry of Copper(II) Monochlorocomplexes in Methanol and Acetonitrile by Broadband Deep-UV-to-Near-IR Femtosecond Transient Absorption Spectroscopy.

A tabletop femtosecond time-resolved soft x-ray transient absorption spectrometer.

Effect of Solvent Hydrogen Bonding on Excited-State Properties of Luminol: A Combined Fluorescence and DFT Study

Solvent effects on excitation relaxation dynamics of a keto-carotenoid, siphonaxanthin.

The solvent effect and identification of a weakly emissive state in nonradiative dynamics of guanine nucleosides and nucleotides--a combined femtosecond broadband time-resolved fluorescence and transient absorption study.