Photoinduced processes in naproxen-based chiral dyads

Jiménez, M. Consuelo; Pischel, Uwe; Miranda, Miguel A.

doi:10.1016/j.jphotochemrev.2007.10.001

Cited by 33 publications

(57 citation statements)

References 64 publications

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“…The difference in lifetimes can be related to the orientation of the drug within the protein, which 10 may restrict the degrees of freedom for conformational relaxation 45 Trp. 38 While this explanation remains a possibility, it can neither be confirmed nor discarded by the present time-resolved experiments. At longer timescales, a slower stereoselective quenching (k > 10 9 s -1 ) of the 1 Trp* fluorescence is also observed, together with exciplex formation.…”

Section: Studies On Fbp/hsa Complexesmentioning

confidence: 63%

“…The fluorescence quantum yields of (S,S)-and (R,S)-FBP-TrpMe were found to be 0.028 and 0.015, respectively (Figure SI-2A), which are much lower than those of 30 the individual chromophores. 38 From the shape and the position of the fluorescence bands, it was confirmed that emission is dominated by 1 TrpMe*. For both dyads, a longer wavelength band (centred at 450 nm), assigned to exciplex emission, was also observed; it was more intense for the (R,S)-diastereomer ( Figure 35 SI-2B).…”

Section: Studies On Fbp-trpme Model Dyadsmentioning

confidence: 81%

“…Interestingly, these profiles are characterised by a rapid rise, 115 ± 7 and 189 ± 6 ps for (S,S)-and (R,S)-, respectively, which can be assigned to the formation of an exciplex. 38 Its rate is intermediate between the two Taking into account the relative absorbances of FBP and HSA 80 at 267 nm, and assuming independent emission, the fluorescence spectrum of the mixture could in principle be calculated using the simple relation…”

Section: Studies On Fbp/hsa Complexesmentioning

confidence: 99%

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Excited state interactions between flurbiprofen and tryptophan in drug–protein complexes and in model dyads. Fluorescence studies from the femtosecond to the nanosecond time domains

Vayá

Bonancía

Jiménez

et al. 2013

Phys. Chem. Chem. Phys.

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We report here on the interaction dynamics between flurbiprofen (FBP) and tryptophan (Trp) covalently linked in model dyads and in a complex of FBP with human serum albumin (HSA) probed by time-10 resolved fluorescence spectroscopy from the femto-to the nano-second timescales. In the dyads, a rapid (k > 10 10 s -1 ) dynamic quenching of the 1 FBP* fluorescence is followed by a slower (k > 10 9 s -1 ) quenching of the remaining 1 Trp* fluorescence. Both processes display a clear stereoselectivity; the rates are 2-3 times higher for the (R,S)-dyad. In addition, a red-shifted exciplex emission is observed, rising in 100-200 ps. A similar two-step dynamic fluorescence quenching is also observed in the FBP/HSA 15 complex, although the kinetics of the involved processes are slower. The characteristic reorientational times determined for the two enantiomeric forms of FBP in the protein show that the interaction is stronger for the (R)-form. This is, to our knowledge, the first observation of stereo-selective flurbiprofentryptophan interaction dynamics with femtosecond time resolution.

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Section: Studies On Fbp/hsa Complexesmentioning

confidence: 63%

Section: Studies On Fbp-trpme Model Dyadsmentioning

confidence: 81%

Section: Studies On Fbp/hsa Complexesmentioning

confidence: 99%

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Excited state interactions between flurbiprofen and tryptophan in drug–protein complexes and in model dyads. Fluorescence studies from the femtosecond to the nanosecond time domains

Vayá

Bonancía

Jiménez

et al. 2013

Phys. Chem. Chem. Phys.

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“…[19][20][21][22][23][24] Since the days of Jabotinsky's works, the photochemical generation of a pair of paramagnetic particles has been used for the modeling of biological processes such as the elementary steps of enzymatic oxygenation and drug-transport protein binding. [25][26][27] This approach is promising in several aspects.…”

Section: Impact Of Chirality On the Photoinduced Charge Transfer In Lmentioning

confidence: 99%

Impact of chirality on the photoinduced charge transfer in linked systems containing naproxen enantiomers

Khramtsova

Sosnovsky

Ageeva

et al. 2016

Phys. Chem. Chem. Phys.

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The model reaction of photoinduced donor-acceptor interaction in linked systems (dyads) has been used to study the comparative reactivity of a well-known antiinflammatory drug, (S)-naproxen (NPX) and its (R)-isomer. (R)-or (S)-NPX in these dyads is linked to (S)-N-methylpyrrolidine (Pyr) using a linear or cyclic amino acid bridge (AA or CyAA), to give (R)-/(S)-NPX-AA-(S)-Pyr flexible and (R)-/(S)-NPX-CyAA-(S)-Pyr rigid dyads. The donor-acceptor interaction is reminiscent of the binding (partial charge transfer, CT) and electron transfer (ET) processes involved in the extensively studied inhibition of the cyclooxygenase enzymes (COXs) by the NPX enantiomers. Besides that, both optical isomers undergo oxidative metabolism by enzymes from the P450 family, which also includes ET. The scheme proposed for the excitation quenching of the (R)-and (S)-NPX excited state in these dyads is based on the joint analysis of the chemically induced dynamic nuclear polarization (CIDNP) and fluorescence data. The 1 H CIDNP effects in this system appear in the back electron transfer in the biradical-zwitterion (BZ), which is formed via dyad photoirradiation. The rate constants of individual steps in the proposed scheme and the fluorescence quantum yields of the local excited (LE) states and exciplexes show stereoselectivity. It depends on the bridge's length, structure and solvent polarity. The CIDNP effects (experimental and calculated) also demonstrate stereodifferentiation. The exciplex quantum yields and the rates of formation are larger for the dyads containing (R)-NPX, which let us suggest a higher contribution from the CT processes with the (R)-optical isomer.

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“…At present, there are only a few examples of the influence of chirality on photochemical processes [4,5,6,7,8,9,10,11,12]. The difference in the radical transformation of the (R) and (S) enantiomers of 2-phenylpropionic acid in the reaction with 4-methyl-2-quinolinecarbonitrile was detected using spin chemistry methods [13].…”

Section: Introductionmentioning

confidence: 99%

Spin effects in intramolecular electron transfer in naproxen-N-methylpyrrolidine dyad

Magin

Polyakov

Khramtsova

et al. 2011

Chemical Physics Letters

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The intramolecular electron transfer in the naproxen-N-methyl-pyrrolidine dyad has been investigated by spin chemistry methods. The existence of CIDNP in a high magnetic field points to electron transfer as a possible mechanism of the quenching of the excited state of a dyad.However, the failure to detect magnetic field effects on triplet yield makes us conclude that this quenching mechanism is not the only one. The observation of CIDNP effects in the dyad in the media of low polarity and the short risetime of triplet state formation indicate a potential role of exciplex in the quenching of the excited state of the dyad.

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Photoinduced processes in naproxen-based chiral dyads

Cited by 33 publications

References 64 publications

Excited state interactions between flurbiprofen and tryptophan in drug–protein complexes and in model dyads. Fluorescence studies from the femtosecond to the nanosecond time domains

Excited state interactions between flurbiprofen and tryptophan in drug–protein complexes and in model dyads. Fluorescence studies from the femtosecond to the nanosecond time domains

Impact of chirality on the photoinduced charge transfer in linked systems containing naproxen enantiomers

Spin effects in intramolecular electron transfer in naproxen-N-methylpyrrolidine dyad

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