Marker dyes for uv and short wave excitation with high stokes shift based on benzoxazoles

A compound of general structure

• or a salt thereof, wherein Z is either
• Z=4-pyridyl
• to form structure I, or
• Z=3-pyridyl
• to form structure II, or
• Z=2-pyridyl
• to form structure III,
• and R2 and/or R7 are each a reactive group A bound via a linker L and adapted to covalently bind a compound of structure I, II or III to a molecule K to be marked,
• wherein A is an amine (—NH2), hydroxy (—OH) or phosphoramidite function (—O—P—[O—CH2—CH2—CN]—N[CH(CH3)2]2), a carboxylic acid (—COOH), an alkyl or active ester derived therefrom (NHS ester, sulfo-NHS ester, tetrafluorophenyl ester, p-sulfotetrafluorophenyl ester);
• a carboxylic acid hydrazide (—CONHNH2);
• or a carboxylic acid amide (—CONHR12) where R12 is —(CH2)t—Y, wherein
• Y is —OH, —NH2, —NH3+, maleimide (—N[CO—CH]2), —NCS, —NCO, —NH—CO—CH2—I, —NH—CO—CH2—Br, azide (—N3), alkyne (—CCH) or phosphoramidite (—O—P—[O—CH2—CH2—CN]—[CH—(CH3)2]2), and
• K is a covalently bound component selected from haptens, proteins (antibodies), low molecular weight drug compounds, peptides, nucleotides, nucleosides, DNA oligomers, polymers, and t represents a number of from 1 to 10, and
• L is a linker selected from a group featuring —(CH2)s—,—[(CH2)m—O]p—(CH2)m—, NR10-(CH2)s—, —O—(CH2)s—, —S—(CH2)s—, —NR10-C(O)—(CH2)s—, —NR10-C(O)—O—(CH2)s—, —NR10-C(O)—NR11-(CH2)s— or —SO2—NR10-(CH2)s—, wherein R10 and R11 are each independently hydrogen, alkyl and alkoxy-alkyl (—[(CH2)m—O]p—CH3), ω-sulfoalkyl (—(CH2)r—SO3), m represents a number of from 2 to 5, p, r and s each independently represent numbers of from 1 to 10.