| abstract |
Compounds of formulae (I), (II) wherein X is an optionally substituted benzyl group which carries an NO2 group in the ortho-position, Z is a group of formula α or β, R, R' and Y are each optionally substituted groups, R'' is hydrogen or alkyl, m and n are each integers of from 1 to 6, and q is an integer of from 1 to 20, and salts thereof. These protected or caged organic compounds, based on the dyes fluorescein (I) and rhodamine (II), can be introduced into biological systems and there released by means of light radiation. They are suitable, for example, for use in the labelling of proteins or lipophilic structures. Processes for the preparation of the compounds are also described. |