Fig. 4: Synthesis of the standards used for the confirmation of the biomarkers.
From: Identification of Δ-1-pyrroline-5-carboxylate derived biomarkers for hyperprolinemia type II
Biomarkers 4-5 were synthesized via (a) an incubation of malonic acid or acetoacetic acid with P5C and b the mixture of diasteroeisomers of 4 was synthesized via N-acyliminium ion chemistry.
