Time-resolved near infrared emission studies have been carried out on a series of nonsteroidal anti inflammatory 2-arylpropionic acids, in order to assess their ability to photosensitize the production of singlet molecular oxygen O2(1Δ(g)). Benoxaprofen, naproxen, tiaprofenic acid, suprafen, ketoprofen and carprofen showed quantum yields for this process (Φ(Δ)) in the range 0.2-0.7 in acetonitrile. Deprotonation of the propionic acid moiety in mixtures of acetonitrile-ethanol (4:1) basified with KOH produced a systematic decrease in Φ(Δ) for all compounds with the exception of naproxen. This effect was even more dramatic in D2O-based phosphate buffer, where no singlet oxygen could be detected for benoxaprofen, ketoprofen or carprofen. The above results are consistent with the occurrence of competing photochemical reactions of 2-arylpropionic acids in different media and particularly with the enhanced photodecarboxylation from the carboxylate anions.
|Nombre de pàgines||5|
|Revista||Photochemistry and Photobiology|
|Estat de la publicació||Publicada - de maig 1997|