Photolabile caged compounds

Loudwig, S., Specht, A. and Goeldner, M. (2002) Caged compounds, the photolabile precursors of bioactive molecules. Developments and prospects. Actualite Chimique, (1), 7-12. 

Figure 15.5 Examples of photolabile protecting groups used for caged compounds, (a) 2-nitrobenzyl (NB) (b) 4,5-dimethoxy-2-nitrobenzyl (DMNB) (c) 2,2 -dinitrobenzhy-dryl (DNB) (d) 3,5-dinitrophenyl (e) 4-methoxyphenacyl.

Hagen, V., Dzeja, C., Bendig, J., Baeger, I., and Kaupp, V.B. (1998) Novel caged compounds of hydrolysis-resistant 8-Br-c AMP and 8-Br-cGMP photolabile NPE esters, J. Photochem. Photobiol. B Biol., 42, 71-78. 

The principles of design and interpretation of kinetic investigations with photolabile precursors can be best illustrated by some of the many uses of npe-ATP. The important parameters to be determined with each compound are the absorption spectrum, quantum yield, rate of appearance of active substrate, the possible binding (competitive inhibition) of the caged compound and the effects of any photoproducts. Additional to these compound specific parameters, instrumentation parameters have to be considered. These are concerned with the light source for photolysis and with the detection equipment. The latter can either monitor the photolytic reaction of the caged compound or the physiological process stimulated by... 

Photolysis of o-Nitrobenzyl Derivatives and Related Compounds. - Although novel types of photolabile protecting groups are continually being developed, the 2-nitrobenzyl system remains popular, especially for photocleav-able linkers in solid-state synthesis or for the photo-induced released of so-called caged molecules. In the period under review, there were few mechanistic studies of the photolysis of 2-nitrobenzyl derivatives, but some significant applications were described. 

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