Photoinduced release of neurotransmitter amino acids from novel coumarin fused julolidine ester cages

Abstract

The photoinduced release of several neurotransmitter amino acids (glycine, alanine, glutamic acid, -alanine and γ-aminobutyric acid) was accomplished from ester cages based on a new photoremovable protecting group consisting of a coumarin built on the julolidine nucleus, namely 11-oxo-2,3,5,6,7,11-hexahydro-1H-pyrano[2,3-f]pyrido[3,2,1-ij]quinolin-9-yl)methyl moiety. Photolysis and steady-state sensitization studies revealed that release of the active molecule occurred in short irradiation times at long wavelengths, with a very promising performance at 419 nm. Given the interest in the development of novel protecting groups cleavable with UV A or even visible radiation, it was found that a structural modification in the coumarin ring by assembly of a fused julolidine lead to a promising photolabile protecting group for organic synthesis and also for bioapplications.