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Published on: October 9, 2021
Excited-state interactions in flurbiprofen-tryptophan dyads
Ignacio Vayá1, M Consuelo Jiménez, Miguel A Miranda
1Departamento de Química/Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, E-46022 Valencia, Spain.
This study investigated flurbiprofen-tryptophan dyads, revealing intramolecular quenching of tryptophan fluorescence. Photophysical analysis showed energy transfer and exciplex formation, with stereoselective effects observed.
Area of Science:
- Photochemistry
- Biophysical Chemistry
- Organic Chemistry
Background:
- Flurbiprofen (FBP) is a nonsteroidal anti-inflammatory drug.
- Tryptophan (Trp) is an amino acid found in human serum albumin.
- Diastereomeric dyads of FBP and Trp were synthesized to study their photophysical interactions.
Purpose of the Study:
- To investigate the photophysical properties of flurbiprofen-tryptophan dyads.
- To understand the energy transfer mechanisms and fluorescence quenching processes.
- To explore stereoselective effects in these molecular systems.
Main Methods:
- Fluorescence spectroscopy
- Laser-flash photolysis
- Synthesis of diastereomeric dyads
Main Results:
- Dramatic fluorescence quenching of tryptophan was observed in the dyads.
- Exciplex emission was detected, particularly for (R,S) diastereomers.
- Shorter fluorescence lifetimes were measured for dyads compared to model compounds.
- Triplet-triplet transient absorption spectra of FBP were obtained, indicating triplet state involvement.
Conclusions:
- Energy transfer from flurbiprofen to tryptophan is a primary event.
- Intramolecular quenching of excited tryptophan is the dominant process.
- Stereoselective deactivation pathways lead to exciplexes and radical ion pairs.
- Triplet energy transfer and back-electron transfer contribute to FBP triplet state population.
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