The present invention provides compounds of the general formula: ##STR1## wherein R.sup.1 is an amino acid residue or a residue of an oligopeptide in which the amino groups are optionally substituted by protective groups, R.sup.2 and R.sup.3, which are the same or different, are hydrogen atoms, a lower alkyl, lower alkoxy, carboxyl or lower alkoxycarbonyl radicals or carboxamido groups optionally substituted by lower alkyl or, if R.sup.2 and R.sup.3 are adjacent, can represent a --CH.dbd.CH--CH.dbd.CH-- radical, Z is a conjugated-through positively charged, bicyclic heterocyclic system and X is an anion of an organic or inorganic acid. The present invention also provides processes for the preparation of these compounds and diagnostic agents containing them for the determination of peptide bond-cleaving enzymes.
本发明提供了通式如下的化合物:##STR1##其中R.sup.1是
氨基酸残基或寡肽残基,其中
氨基可以选择性地被保护基取代,R.sup.2和R.sup.3,相同或不同,是氢原子,较低的烷基,较低的烷氧基,羧基或较低的烷氧羰基基团或羧酰胺基团,可以选择性地被较低的烷基取代,如果R.sup.2和R.sup.3相邻,则可以表示为--CH.dbd.CH--CH.dbd.CH--基团,Z是通过带正电的共轭连接的双环杂环系统,X是有机或
无机酸的阴离子。本发明还提供了制备这些化合物的方法和包含它们的诊断试剂,用于测定肽键裂解酶。