Effects of substituent and excess electron attachment on proton transfer between the radiosensitizer base pairs in aqueous solution

Zhang, Changzhe; Cui, Xueying; Zhao, Yu; Duan, Lingjie; Zhang, Xiao; Meng, Qingtian

doi:10.1016/j.molliq.2022.120216

Cited by 3 publications

(2 citation statements)

References 63 publications

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“…It has also been proposed that halide substituted thymine-adenine can contribute to DNA mutation through a proton transfer reaction, which is qualitatively demonstrated by the substituent-induced hydrogen bond enhancement. It probably helps to understand the mechanism of enhanced DNA damage in radiotherapy and designing radio sensitizing drugs without bio-toxicity [26].…”

Section: Introductionmentioning

confidence: 99%

Excited-state properties of 6-methoxyflavone in the presence of halide ions in aqueous media

Fatma

Pant

Pandey

et al. 2023

Methods Appl. Fluoresc.

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The present work investigated the influence of different halides on the excited state dynamics of 6-methoxyflavone (6MF) in an aqueous solution with steady-state and time-resolved techniques. On successive addition of I¯ and Br¯ ions, the fluorescence (FL) of 6MF quenched significantly, whereas the respective ions do not change the maximum fluorescence band. Fluorescence of 6MF was quenched 66 % by I¯ ions and 34 % by Br¯ ions. In a pure aqueous medium, both the H-bonded: CT and protonated species of 6MF participate in the quenching of FL. The quenching process was categorized by Stern–Volmer (S–V) and Lehrer equations. Quenching parameters such as KSV, KSV-L and kq were higher for I¯ ions than Br¯ ions. The decrease in fluorescence intensity and a reduction in fluorescence lifetime suggested the dynamic nature of quenching by I¯ ions following the electron transfer mechanism. Fluorescence quenching of 6MF has also been observed in the acidic medium in the presence of different halides. Thus, the study reveals that 6MF is responsive towards I¯ ions in a wide range of pH, specifically in a purely aqueous environment (pH~7), hence important for sensing/detection applications.

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Section: Introductionmentioning

confidence: 99%

Excited-state properties of 6-methoxyflavone in the presence of halide ions in aqueous media

Fatma

Pant

Pandey

et al. 2023

Methods Appl. Fluoresc.

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“…We note that several recent works have examined proton transfer reactions in photoexcited base pairs, and their potential contribution to spontaneous mutagenesis via the formation of a rare tautomer in WC base pairs has been a topic of recent theoretical interest. − An enol tautomer, which might be expected to be formed on the TC2 atom in the 2-AP-T base pair in a fashion analogous to that of the proposed C4 enol in the canonical WC base pair, ,, would likely produce an IR signal in the C–O–H stretching and bending region (∼1400 cm –1 ), as we expect a large red shift as the hydrogen on N2 adenine (TC2O···H–N) is transferred to O2 thymine (TC2–OH···N). However, this TC2 enol state is not expected to have a large population as a high activation barrier and a rapid rate of conversion of the enol T back to the keto T have been calculated in previous theoretical studies of the canonical WC base pair. ,,, Experimentally, we do not observe a signal in this region of our C2-edited 2-AP-T difference spectrum (Supporting Figure 7B).…”

mentioning

confidence: 99%

Measuring the Enthalpy of an Individual Hydrogen Bond in a DNA Duplex with Nucleobase Isotope Editing and Variable-Temperature Infrared Spectroscopy

Peng

Castro

Karthikeyan

et al. 2023

J. Phys. Chem. Lett.

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The level of interest in probing the strength of noncovalent interactions in DNA duplexes is high, as these weak forces dictate the range of suprastructures the double helix adopts under different conditions, in turn directly impacting the biological functions and industrial applications of duplexes that require making and breaking them to access the genetic code. However, few experimental tools can measure these weak forces embedded within large biological suprastructures in the native solution environment. Here, we develop experimental methods for detecting the presence of a single noncovalent interaction [a hydrogen bond (Hbond)] within a large DNA duplex in solution and measure its formation enthalpy (ΔH f ). We report that introduction of a H-bond into the TC2�O group from the noncanonical nucleobase 2-aminopurine produces an expected decrease ∼10 ± 0.76 cm −1 (from ∼1720 cm −1 in Watson−Crick to ∼1710 cm −1 in 2-aminopurine), which correlates with an enthalpy of ∼0.93 ± 0.066 kcal/mol for this interaction.

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Proton transfer in Quantum well and Potential barrier models of adenine-thymine and deazaadenine-thymine radical cation: A QM/MM dynamics study

Zhang

Cui

et al. 2023

Chemical Physics Letters

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Effects of substituent and excess electron attachment on proton transfer between the radiosensitizer base pairs in aqueous solution

Cited by 3 publications

References 63 publications

Excited-state properties of 6-methoxyflavone in the presence of halide ions in aqueous media

Excited-state properties of 6-methoxyflavone in the presence of halide ions in aqueous media

Measuring the Enthalpy of an Individual Hydrogen Bond in a DNA Duplex with Nucleobase Isotope Editing and Variable-Temperature Infrared Spectroscopy

Proton transfer in Quantum well and Potential barrier models of adenine-thymine and deazaadenine-thymine radical cation: A QM/MM dynamics study

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