Intramolecular electron transfer between tyrosine and tryptophan photosensitized by a chiral pi,pi* aromatic ketone.
The photochemical reaction of Trp and Tyr and related peptides with Suprofen (SUP) as sensitizer in H2O/CH3CN (28:1 v/v) solutions has been studied by time-resolved spectroscopy. The results show that SUP induces oxidation of both Trp and Tyr, as well as intramolecular-ET reactions in the related peptides. The influence of photosensitizer configuration on the involved processes has been studied by using the enantiomerically pure compounds. A significant chiral recognition is observed in which the concentration of the radicals formed after triplet quenching depends on the configuration of the chiral center; the quenching process is higher when using the (R)-SUP enantiomer.
Galian
Raquel E
RE
Departamento de Química Orgánica/ICMOL, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain.
Pastor-Pérez
Lourdes
L
Miranda
Miguel A
MA
Pérez-Prieto
Julia
J
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D010782:Photolysis; D013237:Stereoisomerism; D013496:Suprofen / Q000737:chemistry*; D014364:Tryptophan / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D014443:Tyrosine; D014364:Tryptophan; D013496:Suprofen