D-Pyroglutamic acid, also known as 5-oxo-D-proline, is a metabolite of D-glutamate.1 It is formed from D-glutamate by D-glutamate cyclase. The levels of D-pyroglutamic acid are increased in the urine of patients with nascent metabolic syndrome and the plasma of patients with end-stage renal disease.2,3
1.Ariyoshi, M., Katane, M., Hamase, K., et al.D-Glutamate is metabolized in the heart mitochondriaSci. Rep.743911(2017) 2.Shim, K., Gulhar, R., and Jialal, I.Exploratory metabolomics of nascent metabolic syndromeJ. Diabetes Complications33(3)212-216(2019) 3.Palekar, A.G., Tate, S.S., Sullivan, J.F., et al.Accumulation of 50oxo-L-proline and 5-oxo-D-proline in the blood plasma in end stage renal diseaseBiochem. Med.14(3)339-345(1975)