PHOTOSENSITIVE CALCIUM CHELATORS

摘要

NEW PHOTOSENSITIVE CALCIUM CHELATORS The present invention discloses a new class of calcium chelating compounds which have a decreased affinity for calcium following illumination. These new compounds contain a photolabile nitrobenzyl derivative coupled to a tetracarboxylate Ca2+ chelating parent compound having the octacoordinate chelating groups characteristic of EGTA or BAPTA. However unlike EGTA or BAPTA-like compounds, in which the two halves of the chelator are linked by a simple 1,2-ethanediyl moiety, the compounds of the present invention modify the stereochemical conformation of this linkage by adding bulky substituents or incorporating the linkage into a carbocyclic or heterocyclic ring. In a first form, the new compounds are comprised of a BAPTA-like chelator coupled to a single 2-nitrobenzyl derivative, which in turn is a photochemical precursor of a 2-nitrosobenzophenone. In a second form, the new compounds are comprised of a BAPTA-like chelator coupled to two 2-nitrobenzyl derivatives, themselves photochemical precursor of the related 2-nitrosobenzophenones.