Redoxactive Oligonucleotides: Synthesis and Properties of Flavocoenzyme‐DNA

Mees, Alexandra; Behrens, Christoph; Schwögler, Anja; Ober, Mat­thias; Carell, Thomas

doi:10.1002/ejoc.200300066

Cited by 3 publications

(2 citation statements)

References 50 publications

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“…The less than or equal sign in eqn (10) refers to the fact that the last step of the reaction, which at the moment lies beyond our The QY of proton transfer F PT corresponds to the parameter b = 0.3 that was used to obtain the SAS (see Section 3.4). Thus, k ISC is the only free parameter that is not a priori known from the spectroscopic analysis.…”

Section: Mechanism Of the Photocatalytic Mba Oxidationmentioning

confidence: 99%

“…Preparative flavin-mediated photooxidations 2,3 were investigated by Shinkai, 4,5 Fukuzumi 6-8 and others. [9][10][11][12] To enhance the photocatalytic efficiency and photocatalyst stability, heterocyclic substrate binding sites or flavin transition metal complexes have been used. The redox properties of flavin were modulated by hydrogen bonding and transition metal complexation.…”

Section: Introductionmentioning

confidence: 99%

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Unraveling the flavin-catalyzed photooxidation of benzylic alcohol with transient absorption spectroscopy from sub-pico- to microseconds

Megerle

Wenninger

Kutta

et al. 2011

Phys. Chem. Chem. Phys.

102

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Flavin-mediated photooxidations have been described for applications in synthetic organic chemistry for some time and are claimed to be a route to the use of solar energy. We present a detailed investigation of the involved photophysical and photochemical steps in methoxybenzyl alcohol oxidation on a timescale ranging from sub-picoseconds to tens of microseconds. The results establish the flavin triplet state as the key intermediate for the photooxidation. The initial step is an electron transfer from the alcohol to the triplet state of the flavin catalyst with, followed by a proton transfer in B6 ms. In contrast, the electron transfer involving the singlet state of flavin is a loss channel. It is followed by rapid charge recombination (t = 50 ps) without significant product formation as seen when flavin is dissolved in pure benzylic alcohol. In dilute acetonitrile/water solutions of flavin and alcohol the electron transfer is mostly controlled by diffusion, though at high substrate concentrations >100 mM we also find a considerable contribution from preassociated flavin-alcohol-aggregates. The model including a productive triplet channel and a competing singlet loss channel is confirmed by the course of the photooxidation quantum yield as a function of substrate concentration: We find a maximum quantum yield of 3% at 25 mM of benzylic alcohol and significantly smaller values for both higher and lower alcohol concentrations. The observations indicate the importance to perform flavin photooxidations at optimized substrate concentrations to achieve high quantum efficiencies and provide directions for the design of flavin photocatalysts with improved performance.

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Section: Mechanism Of the Photocatalytic Mba Oxidationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Unraveling the flavin-catalyzed photooxidation of benzylic alcohol with transient absorption spectroscopy from sub-pico- to microseconds

Megerle

Wenninger

Kutta

et al. 2011

Phys. Chem. Chem. Phys.

102

View full text Add to dashboard Cite

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Electron transfer processes in DNA: mechanisms, biological relevance and applications in DNA analytics

Wagenknecht

2006

Nat. Prod. Rep.

124

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In principle, DNA-mediated charge transfer processes can be categorized as oxidative hole transfer and reductive electron transfer. With respect to the routes of DNA damage most of the past research has been focused on the investigation of oxidative hole transfer or transport. On the other hand, the transport or transfer of excess electrons has a large potential for biomedical applications, mainly for DNA chip technology.

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Redox-triggered switching of helical chirality of poly(phenylacetylene)s bearing riboflavin pendants

Iida

Mizoguchi

et al. 2010

Polym. Chem.

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Two novel optically active poly(phenylacetylene)s bearing riboflavin (vitamin B 2 ) residues as the pendant through different covalent linkages (poly-1 and poly-2) were prepared by the polymerization of the corresponding monomers (1 and 2) with a rhodium catalyst, and their chiroptical properties were investigated by UV-visible and circular dichroism (CD) spectroscopies. Riboflavin-linked poly-2 through the acetal linkage with the ribityl group to the phenylacetylene exhibited a relatively intense induced CD (ICD) in the polymer backbone region. The ICD was temperature-dependent, indicating that the main chain of poly-2 adopts a dynamic preferred-handed helical conformation induced by the optically active ribityl group. In contrast, poly-1 having the riboflavin pendant via the N 3 -methylene linker showed almost no apparent ICD due to the main-chain helical conformation, probably because the optically active ribityl group of poly-1 is located relatively far from the polymer backbone compared with poly-2. The cyclic voltammetric measurements of poly-1 and poly-2 revealed that these polymers possess reversible redox properties originating from the electron transfer process of the riboflavin pendants. The switching of the chiroptical properties in response to the redox stimuli was also investigated using a chemical reductant (Na 2 S 2 O 4 ) and oxidant (O 2 ).

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Redoxactive Oligonucleotides: Synthesis and Properties of Flavocoenzyme‐DNA

Cited by 3 publications

References 50 publications

Unraveling the flavin-catalyzed photooxidation of benzylic alcohol with transient absorption spectroscopy from sub-pico- to microseconds

Unraveling the flavin-catalyzed photooxidation of benzylic alcohol with transient absorption spectroscopy from sub-pico- to microseconds

Electron transfer processes in DNA: mechanisms, biological relevance and applications in DNA analytics

Redox-triggered switching of helical chirality of poly(phenylacetylene)s bearing riboflavin pendants

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