Charge-Transfer Quenching of Singlet Oxygen O2(1Δg) by Amines and Aromatic Hydrocarbons

Darmanyan, A. P.; Jenks, William S.; Jardon, Pierre

doi:10.1021/jp982326o

Cited by 84 publications

(95 citation statements)

References 60 publications

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“…18) The 1 O 2 physical quenching mechanism involves the process of charge-transfer from N-lone electron pair of amine to O 2 , and the 1 O 2 quenching efficiency of tertiary amines are larger than primary amines because of its low ionization potentials. 18,19) Therefore, it is possible that N,N-dimethylaminomethylene group of DFM and DFP contributes to increase k q compared to amido group of 6FP and FM. This may be the reason why the 1 O 2 scavenging activities of DFM and DFP were more potent than those of 6FP and FM.…”

Section: Resultsmentioning

confidence: 99%

Substituent Effects of Pterin Derivatives on Singlet Oxygen Scavenging Activity

Mori

Nishinaka²,

Nonogawa

et al. 2010

Biological & Pharmaceutical Bulletin

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The relationship of chemical structures of 6-formylpterin (6FP) and its derivatives with scavenging activity of singlet oxygen ((1)O(2)) was examined. First, effects of pterin derivatives on (1)O(2) released from activated human neutrophils were examined. The neutrophils, stimulated with opsonized zymosan, released (1)O(2) that was detected by chemiluminescence using a (1)O(2) specific probe, trans-1-(2'-methoxyvinyl)pyrene. 6FP and its derivatives suppressed the (1)O(2) release. 6FP and other commercially available pterin derivatives, such as biopterin and neopterin, which have different substitutions at the 6-position, suppressed the (1)O(2) release with similar extent. On the other hand, newly synthesized pterin derivatives, which have different substitutions at the 2- and/or 3-position, such as 2-amino-6-formyl-3-methylpteridin-4-one, suppressed the (1)O(2) release in a dose-dependent manner and more potently than 6FP. Then, the (1)O(2) scavenging activity of pterin derivatives was examined photochemically by direct analysis of near-infrared luminescence at 1270 nm, the most sensitive method for the detection of (1)O(2). When rose Bengal, a photosensitizer, in D(2)O solution, was irradiated by 514 nm laser beam, the emission spectrum of (1)O(2) was observed. 6FP suppressed this emission spectrum of (1)O(2), and the newly synthesized pterin derivatives with different substituent at the 2- and/or 3-position suppressed the spectrum more potently than 6FP. The order of potency was similar to that obtained from biological assays. These findings indicate that the substitutions at the 2- and/or 3-position play an important role in (1)O(2) scavenging activity of pterin derivatives.

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Section: Resultsmentioning

confidence: 99%

Substituent Effects of Pterin Derivatives on Singlet Oxygen Scavenging Activity

Mori

Nishinaka²,

Nonogawa

et al. 2010

Biological & Pharmaceutical Bulletin

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“…For example, can the photoreleased amine provide protection as stabilizers from unwanted photooxidation of cyanine, that is, nonselective reactions elsewhere than the C(21)=C(22) bond? Furthermore, does the amine product ability to physically quench 1 O 2 hinder this reaction sequence thus leading to diminishing returns in the photorelease process?…”

Section: Commentarymentioning

confidence: 99%

Cyanine Modification Tuned for Amine Photorelease

Mathew

Greer

2019

Photochem & Photobiology

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Cyanines are emerging as useful agents for photoreleasing biological compounds because of their capability of utilizing near‐infrared (NIR) light. Another benefit is their ability to self‐sensitize to produce singlet oxygen for the release of aryl amines, a process that has not been as feasible in the past. Here, we highlight the paper by Schnermann et al. (https://doi.org/10.1111/php.13090), which reports on a cyanine conjugate for heterolytic photocleavage of aryl amines. This paper is timely—delving into a photorelease mechanism involving a domino rearrangement and β‐elimination triggered by NIR light.

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“…44 Aniline without halogenated substituent has the higher k Q value than the compounds with chlorine and bromine in acetonitrile, possibly due to halogens (-F, -Cl and -Br) are electron withdrawing groups (EWGs) and inefficient for electron delocalization, hence with a lower capacity to stabilize resonance structures. Along, the heavy-atom contribution on rate constant k Q has been studied, several halogenated anilines with similar oxidation potentials were used as quenchers.…”

Section: Overall Rate Constants (K Q ) For the Quenching Of 1 Omentioning

confidence: 99%

Novel (E)-1-(pyrrole-2-yl)-3-(aryl)-2-(propen-1-one) derivatives as efficient singlet oxygen quenchers: kinetics and quantum chemical calculations

et al. 2015

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†Electronic Supplementary InformaƟon (ESI) available: Cartesian coordinates (and geometries) of the ground and first triplet states computed by quantum chemical calculations as well as the IR and NMR experimental spectra are presented. See Chalcones constitute an important group of natural and synthetic products that have been screened due to their wide range of pharmacological applications. Herein, we studied the antioxidant activity of five newly synthetized (E)-1-(pyrrole-2-yl)-3-(aryl)-2-(propen-1-one) (PAPs) derivatives against singlet oxygen ( 1 O2). The differences among the compounds are related to the aryl substitution in the p-position where: 3a = C6H5, 3b = 4-H3COC6H4, 3c = 4-FC6H4, 3d = 4-ClC6H4, 3e = 4-BrC6H4. The PAPs were synthesized by Claisen-Schmidt condensation reaction between 2-acetylpyrrole and aromatic aldehydes under ultrasonic irradiation (yields between 79-86%) and were characterized by IR, mass spectrometry, NMR and quantum chemical calculations. The total singlet oxygen quenching rate constants (kQ) by the PAPs were measured spectrophotometrically in ethanol at 25 °C and determined by using the Stern-Volmer model. As the character of the EWGs is increased from 3a to 3e, the kQ diminishes smoothly. The best quencher is found to be the 3a compound (where the aryl group is unsubstituted) with a kQ = 5.71 (±0.21) x10 7 M -1 s -1 , which is similar to those for other antioxidants e.g. flavonoids. These results suggest these compounds as efficient quenchers of singlet oxygen and their potential aplicability in biological systems.

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Charge-Transfer Quenching of Singlet Oxygen O₂(¹Δ_g) by Amines and Aromatic Hydrocarbons

Cited by 84 publications

References 60 publications

Substituent Effects of Pterin Derivatives on Singlet Oxygen Scavenging Activity

Substituent Effects of Pterin Derivatives on Singlet Oxygen Scavenging Activity

Cyanine Modification Tuned for Amine Photorelease

Novel (E)-1-(pyrrole-2-yl)-3-(aryl)-2-(propen-1-one) derivatives as efficient singlet oxygen quenchers: kinetics and quantum chemical calculations

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