L-Proline-13C5,15N,d7 is the deuterium, 13C and 15N labeled L-Proline[1]. L-Proline is one of the twenty amino acids used in living organisms as the building blocks of proteins.
References
[1] Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019 Feb;53(2):211-216. DOI:10.1177/1060028018797110
