Influence of the spacer on the photoreactivity of flurbiprofen-tyrosine dyads

Abstract

[EN] The photoreactivity of diastereomeric dyads containing (S)- or (R)-flurbiprofen (FBP) and (S)-Tyr, either directly linked (1) or separated by a cyclic spacer (3) has been investigated. The main feature is a remarkable intramolecular quenching of FBP fluorescence, especially in 1. The process is clearly configuration dependent, being more efficient for the (R,S)- diastereomer in 1 and for the (S,S)-analogue in 3. Noteworthy, exciplex emission is detected in the 380-500 nm region in the case of 3. Fluorescence decay kinetics from the femtosecond to the nanosecond time-domains provides evidence for the dynamic nature of the quenching. In agreement with the steady-state and time-resolved observations, molecular modelling points to a more favourable geometric arrangement of the two interacting chromophores in 1 than in 3. ; Financial support from the Spanish Government (CTQ2013-47872-C2-1-P), EU (PCIG12GA-2012-334257, LASERLAB-EUROPE grant agreement no. 284464, EU FP7, and MSCA- 657465) and Generalitat Valenciana (PROMETEOII/2013/005) is gratefully acknowledged. ; Vayá Pérez, I.; Gustavsson, T.; Markovitsi, D.; Miranda Alonso, MÁ.; Jiménez Molero, MC. (2016). Influence of the spacer on the photoreactivity of flurbiprofen-tyrosine dyads. Journal of Photochemistry and Photobiology A: Chemistry. 322:95-101. https://doi.org/10.1016/j.jphotochem.2016.03.006 ; S ; 95 ; 101 ; 322