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• W1544131754 abstract "A new water-soluble photoremovable protecting group for carboxylic acids and phosphateswith high molar extinction coefficients (eλmax ~ 25 000 dm3mol-1cm-1) in the visible region(above 520 nm) was designed and tested. The suggested concept based on the photochemistryof coumarinyl PPG proved to work also for the compounds derived from 6-hydroxy-3-oxo-3H-xanthen-9-yl)methyl. The introduction of an additional aromatic core to the coumarinylunit resulted in a substantial shift of the absorption towards longer wavelengths and alsocaused a drop in pKa of the phenolic protons to about 6, which then caused the anionic form ofthe molecule to be the prevalent species at neutral pH. This is of advantage since it improvesthe solubility of these compounds in aqueous media and also because the anionic forms of thecages are even further red-shifted with respect to the neutral ones.The model cages released the protected bromide, acetate and/or diethylphosphate uponirradiation by visible light in neutral aqueous solutions (the cleavage of the free anions wasindicated by a drop in pH and confirmed by NMR).The quantum yields of photodeprotection of the model compounds were relatively low butstill comparable to those of coumarinyl cages. The quantum yields could probably beenhanced by a suitable substitution. The efficiency of the photoreaction is also likely to behigher in the case of cages of other phosphates and/or acyls of biochemical interest, which arebetter leaving groups than diethyl phosphate or acetate.In the dark, the model compounds were stable for several hours (up to 1 day) in aqueoussolutions at room temperature. The stability should thus be sufficient for potentialbiochemical applications.The fluorescence lifetime of one of the model compouds, 9-(bromomethyl)-6-hydroxy-3Hxanthen-3-one was found to be (331 ± 30) ps.The last problem that remains to be solved is an unequivocal identification of the finalphotoproduct and of the reaction intermediates. The first step of the photoreaction is mostprobably analogous to that of coumarinyl cages, i.e. the elimination of the protected species(free acids) and the nucleophilic attack of the resulting cation by water, which leads to theformation of the primary photoproduct, 6-hydroxy-9-(hydroxymethyl)-3H-xanthen-3-one.This compound is in equilibrium with its enol tautomer and also with another tautomer:3,6-dihydroxy-9H-xanthene-9-carbaldehyde. One or more of these tautomers react further togive a final product, in which the original chromophore is restored again (testified by UV-Visspectroscopy and NMR). The UV-Vis spectrum of the final photoproduct overlaps with thespectrum of 6-hydroxy-3H-xanthen-3-one but the NMR analysis revealed that the two compoundswere not identical. Further analyses and attempts to identify the photoproduct and the reactionintermediates are still in progress." @default.
• W1544131754 created "2016-06-24" @default.
• W1544131754 creator A5041727774 @default.
• W1544131754 date "2007-01-01" @default.
• W1544131754 modified "2023-09-23" @default.
• W1544131754 title "A new photoremovable protecting group absorbing above 500 nm : (6-Hydroxy-3-oxo-3H-xanthen-9-yl)methyl and its derivates" @default.
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• W1544131754 cites W1964476192 @default.
• W1544131754 cites W1966702530 @default.
• W1544131754 cites W1979629823 @default.
• W1544131754 cites W1979868186 @default.
• W1544131754 cites W1984498335 @default.
• W1544131754 cites W1988131005 @default.
• W1544131754 cites W1988217500 @default.
• W1544131754 cites W1989537211 @default.
• W1544131754 cites W1995047705 @default.
• W1544131754 cites W1999499042 @default.
• W1544131754 cites W2001866340 @default.
• W1544131754 cites W2002921086 @default.
• W1544131754 cites W2003652884 @default.
• W1544131754 cites W2003980650 @default.
• W1544131754 cites W2006058557 @default.
• W1544131754 cites W2006381939 @default.
• W1544131754 cites W2012539867 @default.
• W1544131754 cites W2017916715 @default.
• W1544131754 cites W2019652237 @default.
• W1544131754 cites W2021184371 @default.
• W1544131754 cites W2021840869 @default.
• W1544131754 cites W2022243850 @default.
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• W1544131754 cites W2037509330 @default.
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• W1544131754 cites W2064039337 @default.
• W1544131754 cites W2064557242 @default.
• W1544131754 cites W2064584456 @default.
• W1544131754 cites W2067602573 @default.
• W1544131754 cites W2071831208 @default.
• W1544131754 cites W2076472806 @default.
• W1544131754 cites W2076809828 @default.
• W1544131754 cites W2077490712 @default.
• W1544131754 cites W2078668386 @default.
• W1544131754 cites W2080063173 @default.
• W1544131754 cites W2081876025 @default.
• W1544131754 cites W2082305442 @default.
• W1544131754 cites W2085082978 @default.
• W1544131754 cites W2085349238 @default.
• W1544131754 cites W2086464766 @default.
• W1544131754 cites W2089196233 @default.
• W1544131754 cites W2089742414 @default.
• W1544131754 cites W2092435369 @default.
• W1544131754 cites W2095453725 @default.
• W1544131754 cites W2103443238 @default.
• W1544131754 cites W2108550916 @default.
• W1544131754 cites W2110010969 @default.
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• W1544131754 cites W2142720148 @default.
• W1544131754 cites W2148657407 @default.
• W1544131754 cites W2155550943 @default.
• W1544131754 cites W2159511216 @default.
• W1544131754 cites W2169873791 @default.
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• W1544131754 doi "https://doi.org/10.5451/unibas-004389486" @default.
• W1544131754 hasPublicationYear "2007" @default.
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