The indicator compounds of the present invention are substituted or unsubstituted BAPTA-type chelators that contain a benzazolyl-coumarin substructure, and the pharmaceutically acceptable non-toxic salts and esters thereof. These compounds are useful for the detection and quantification of polycationic metal ions, particularly Ca.sup.2+. The compounds of the invention have the core structure ##STR1## or the structure ##STR2## where m=2 or 3 and X can be S, O, or C(CH.sub.3).sub.2. The above core structures are optionally substituted by substituents that alter the binding affinity of the indicator, shift the spectral properties of the indicator, or act as a reactive site for the preparation of a variety of conjugates.
本发明的指示化合物是含有
苯并咪唑-
香豆素亚结构的取代或未取代BA
PTA型
螯合剂,以及其药学上可接受的无毒盐和酯。这些化合物对于检测和定量多阳离子
金属离子特别是Ca.sup.2+非常有用。本发明的化合物具有核心结构##STR1##或结构##STR2##其中m=2或3,X可以是S,O或C(CH.sub.3).sub.2。上述核心结构可选地被取代,以改变指示剂的结合亲和力,转移指示剂的光谱特性,或作为制备各种共轭物的反应位点。