Molecular renal probes for detecting acute kidney injury

A compound of formula I:

• (X)a—Y—(Z)b I
• where:
• X is selected from:
• where R1 represents a biomarker reactive moiety conjugated to a self-immolative moiety
• wherein the self-immolative moiety is selected from:
• where the heteroatom directly bonded to the aromatic ring represents the point of attachment to Y and the other heteroatoms represent the point of attachment to a biomarker reactive moiety or are H, provided that at least one of the other heteroatoms is attached to a biomarker reactive moiety;
• R2 represents a point of attachment to Y and R2′ represents another point of attachment to the same Y group or a point of attachment to a second Y group;
• R3 represents H, SO3H or COOH;
• Z is selected from:
• R4 is selected from:
• where the wavy line represents the point of attachment to the rest of the molecule;
• R4′ represents the point of attachment to Y;
• each Y is selected from:
• where the wavy line represents the point of attachment to X or Z,
• where the wavy line represents the point of attachment to X or Z,
• where each R5 is independently selected from H, CH2CHOHCH3, CH2CCH, and
• where the left-hand wavy line (adjacent to m) represents the point of attachment to X or Z and the right-hand wavy line represents the point of attachment to the rest of the molecule;
• a is 0 or 1 and b is 1, provided that:
• at least one of a and b is 1;
• and
• when a and b are both 1, Y is selected from:
• or pharmaceutically acceptable salts and/or solvates thereof, provided that when X is
• then Z is 0.