Diagnostic agents for the detection of leukocytes in body fluids

Diagnostic agent for the detection of esterolytic and proteolytic enzymes in body fluids, which agent comprises at least one substrate, and adjuvants suitable for said substrate, and at least one activator, and wherein said substrate is a sulphonphthalein ester of the formula ##STR5## wherein R.sub.1 " is a carboxylic acid residue optionally substituted by halogen or a lower alkoxy radical or is an amino acid or peptide residue provided with a nitrogen protective group conventional in peptide chemistry;

• R.sub.2 " is a halogen atom or a lower alkyl radical;
• and
• R.sub.3 " and R.sub.4 ", which can be the same or different are hydrogen or halogen atoms;
• or an azo dyestuff ester of the formula
• A'--N.dbd.N--B'(OR).sub.n
• wherein
• A' is a five- or six-membered, optionally benzo-annellated residue with one or two heteroatoms selected from nitrogen, sulfur and oxygen, which is optionally substituted one or more times by halogen, lower alkyl or lower alkoxy radicals or is a phenyl radical substituted one, two or three times by lower alkyl, lower alkoxy, nitro, sulphonato or acylamino radicals;
• B' is a benzene, naphthalene or quinoline radical optionally substituted once or twice by sulphonato, lower alkoxy or lower alkoxypolyalkyleneoxy radicals;
• R is a carboxylic acid residue or an amino acid or peptide residue provided with a nitrogen protective group conventional in peptide chemistry;
• and
• n is 1 or 2;
• or an indoxyl ester of the formula ##STR6## wherein R.sub.1 '", R.sub.2 '", R.sub.3 '" and R.sub.4 '", which can be the same or different, are hydrogen or halogen atoms, lower alkyl, lower alkoxy, aryl, aralkyl, aralkoxy, hydroxyl, carboxy, carboxy lower alkoxy, aralkoxycarbonyl, aralkoxycarbonyl lower alkoxy, nitro or lower acylamino radicals or in which two adjacent substituents represent a benzo-annellated residue optionally substituted by halogen;
• X is a sulfur atom or an imino group optionally substituted by a lower alkyl, aryl, aralkyl or acyl radical;
• A" is an amino acid or peptide residue;
• and
• B" is a nitrogen protective group conventional in peptide chemistry or derived therefrom.
• and said activator is selected from the following:
• (a) pyridine derivatives of the general formula:
• ##STR7## in which R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5, which can be the same or different, are hydrogen or halogen atoms, lower alkyl or lower alkoxy radicals, vinyl radicals which are substituted by an aryl radical optionally substituted one or more times by lower alkoxy, amino, alkylamino or dialkylamino, or by a heterocyclic radical, whereby two adjacent substituents can represent an indeno- or benzo-annellated residue optionally substituted one or more times by halogen, hydroxyl, lower alkyl or lower alkoxy, which annellated residue can, in turn, carry a benzo- or pyrido-annellated residue optionally substituted by a lower alkyl radical and R.sub.3 can also stand for a vinylquinuclidyl-carbinol radical;
• (b) imidazole derivatives of the general formula:
• ##STR8## in which R.sub.1 ' is a hydrogen atom, a lower alkyl radical or an aryl radical optionally substituted by a hydroxyl group or an acyl radical and R.sub.2 ' is a hydrogen atom, an aminoalkyl, N-acylaminoalkyl or a lower aliphatic, optionally unsaturated carboxylic acid residue or a lower aliphatic .alpha.-amino acid residue optionally acylated on the nitrogen;
• (c) alcohols of the general formula:
• X--A--OH
• in which X is a hydrogen atom or a hydroxyl group and A is a hydrocarbon radical;
• (d) metal complexes of the general formula:
• D.sub.m [B(CN).sub.n (NO).sub.p ]
• in which D is an alkali metal ion, B is a heavy metal ion, m is 2, 3, 4 or 5, n is 4, 5, 6, 7 or 8 and p is 0 or 1, the number m being given by the valency of the heavy metal ion and the number n.