RESUMO
The immobilization of some coumarin derivatives on modified poly(ethylene glycol)s is reported and the influence of the polymeric support on the photoluminescence activity of the compounds is discussed. Upon ultraviolet excitation, the derivatives showed coumarin-related emission properties whose peak position and efficiency depended on the loading of the polymer and on the mesomeric effects of the substituents.
Assuntos
Cumarínicos/efeitos da radiação , Luminescência , Cumarínicos/química , Polietilenoglicóis/química , Relação Estrutura-Atividade , Raios UltravioletaRESUMO
Tandem mass spectrometry has been applied to differentiate three sets of o-, m- and p-methyl, -methoxy and -nitro-substituted-6-phenyl-dibenzo(d,f)(1,3)dioxepines. Collision-induced dissociation (CID) experiments have been carried out on 2-phenylbenzo[b]furan fragment ions, which originate from the decomposition of the molecular ions after their EI-induced isomerization to spirocyclic structures. With the exception of m- and p-methylphenylbenzo[b]furan isomers, which display identical CID mass spectra, the three isomeric methoxy- and nitrophenylbenzo[b]furan fragment ions display very characteristic CID behavior which allows unequivocal differentiation of the 6-phenyl-dibenzo(d,f)(1,3)dioxepine isomers. 6-(o-nitrophenyl)-dibenzo(d,f)(1,3)dioxepine isomer, does not form a 2-(o-nitrophenyl)benzo[b]furan ion and, therefore, it can be differentiated from the m- and p- isomers based on the mere EI mass spectra. Furthermore, it shows a characteristic ion most likely due to an ortho effect between the nitro group and the dioxepine ring. Multiple stage mass spectrometric techniques (MSn), labeled derivatives and reference compounds were used in order to gain additional information on the structures of product ion from the CID fragmentation.
RESUMO
In this work, the PEG-immobilization and the liquid phase synthesis of some coumarins derived from cardol are presented. Some preliminary results on their tyrosinase inhibitory activity are also included.
Assuntos
Agaricales/enzimologia , Cumarínicos/síntese química , Cumarínicos/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Polietilenoglicóis , Polímeros , Resorcinóis/química , Proteínas Fúngicas , SolubilidadeRESUMO
The mass spectrometric behaviour of a series of 6,6-disubstituted dibenzo(d,f)(1,3)dioxepine derivatives have been studied. The fragmentation patterns were described and discussed in detail with the aid of labelled compounds, accurate mass measurements and collisionally induced dissociation experiments performed using an ion trap.