Chromogenic substrate to peroxidase enzymes

Claim 1

A chromogenic substrate to peroxidase enzymes comprised of a mixture of: (a) a hydrzone compound of the formula: ##STR6## wherein: R contains from 1 to 25 carbon atoms and is selected from the group consisting of alkyl, alkenyl, aralkyl, alkoxyalkylo, aryloxyalkyl, hydroxyalkyl, carboxyalkyl, carboalkoxyalkyl, arylthioalkyl, sulfonylalkyl; R 1 and R 3 represent hydrogen, alkyl, aryl, heteroaryl, alkoxycarbonyl, amino, alkylamino, dialkylamino, arylamino, heteroarylamino, and can contain up to 18 carbon atoms, and wherein any heteroatoms are selected from O, N and S; R 2 and R 4 represent hydrogen, alkyl, aryl, heteroaryl, carboxyl, alkoxycarbonyl, alkylcarbonyl, arycarbonyl, amino, alkylamino, dialkylamino, arylamino, heteroarylamino, sulfonic acid, alkylsulfonykl, arylsulfonyl, vinyl sulfonyl, and can contain up to 18 carbon atoms, and wherein any heteroatoms are selected from O, N and S; and wherein R1 and R4 can together with the atoms to which they are attached, form a cyclic or bicyclic 5 or 6 membered ring which can contain one or more heteroatoms of the group of O, S and N, and can contain a carbonyl or a thiocarbonyl group; Y represents methylene or nitrogen; Z represents a group of up to 25 carbon atoms containing non-metallic atoms necessary to complete a cyclic or bicyclic ring with the atoms to which it is attached and which ring may contain at least on heteroatom of the group oxygen and sulfur, and wherein Z can be substituted with one or more substituents selected from the group consisting of lower alkyl, nitro, halogen, carboxyl sulfonyl, amino and diamino groups; and n has a value of 1 when Y is carbon and 0 when Y is nitrogen; and (b) a mono-cyclic or polycyclic aryl or heteroaryl compound containing up to about 24 carbon atoms, and which is substituted with at least one hydroxyl or amino groups, and which is selected from the group consisting of phenols, naphthols, anilines, aminonaphthalenes, aminonaphthols, pyridines, quinolines, diazoles, oxazoles and thiazoles.