2-Ketoglutaric acid-13C (Alpha-Ketoglutaric acid-13C) is a 13C labeled 2-Ketoglutaric acid (HY-W013636)[1]. 2-Ketoglutaric acid (Alpha-Ketoglutaric acid) is an intermediate in the production of ATP or GTP in the Krebs cycle. 2-Ketoglutaric acid also acts as the major carbon skeleton for nitrogen-assimilatory reactions. 2-Ketoglutaric acid is a reversible inhibitor of tyrosinase (IC50=15 mM)[2][3].