Photolytic release of bioactive carboxylic acids from fused pyran conjugates

•Coumarins with amino and aryl substituents were synthesized and used in the derivatization of glycine and β-alanine.•The new ester cages, as models of carboxylic acid bioactive molecules, revealed to be interesting photo-responsive units.•A remarkable behaviour towards irradiation at higher wavelengths occurred in conjugates bearing the styryl-coumarin.•Time-resolved fluorescence studies revealed different fluorescing species by the determination of decay associated spectra.•This study shows new promising alternative moieties for the development of photoactivable fluorescent acid prodrugs.

New ester cages bearing the coumarin (2H-benzopyran-2-one) skeleton with extended π-systems as phototriggers, for glycine and β-alanine, as models of carboxylic acid bifunctional molecules with biological relevance, were evaluated under photolysis conditions at 254, 300, 350 and 419 nm of irradiation in a RPR-100 photochemical reactor. The processes were followed by HPLC-UV detection and 1H NMR with collection of kinetic data. The results showed a correlation between the photolysis efficiency and the increasing extension of the conjugation for both glycine and β-alanine, showing that the 7-aminocoumarin afforded the best results at all wavelengths tested.From a study of the time-resolved fluorescence behaviour, these compounds were also found to exhibit more complex fluorescence decay kinetics. This was attributed to the presence of conjugated and non-conjugated coumarin species.

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