The molecule is a dipeptide composed of L-proline and L-hydroxyproline residues. It is a biomarker for bone collagen degradation. It has a role as a diagnostic agent, a human metabolite and a biomarker. It derives from a L-proline and a trans-4-hydroxy-L-proline. It is a tautomer of a Pro-Hyp zwitterion.
(2S,4R)-4-hydroxy-1-[(2S)-pyrrolidine-2-carbonyl]pyrrolidine-2-carboxylic acid