Synonyms: 2-Ketoglutaric acid, α-ketoglutarate, 2-oxoglutaric acid, 2-oxoglutarate.
Method(s): GC-MS/MS (1).
What is α-ketoglutaric acid?
α-Ketoglutaric acid is a keto acid of the Krebs cycle that is converted to succinate through the action of the thiamine pyrophosphate (TPP) -dependent enzyme, α-ketoglutarate dehydrogenase. α-Ketoglutaric acid is also connected to glutamic acid metabolism through the pyridoxal 5´-phosphate-dependent transamination reaction. The α-ketoglutarate:glutamate ratio is almost doubled after dietary vitamin B-6 restriction, suggesting that the ratio may serve as a functional marker of vitamin B6 status (2).
Performance of the assay
Lower limit of detection (LOD): na.
Within-day CV: 5 %; between-day CV: na.
α-Ketoglutaric acid may be a marker of thiamine deficiency.
The α-ketoglutarate:glutamate ratio is a putative marker of vitamin B6 status.
Specimen, collection and processing
Patient/subject: No special precaution.
Matrix: Serum or EDTA plasma.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Probably stable.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values: 20-50 µmol/L
Intraclass correlation coefficient (ICC): na.
1. Midttun, Ø., McCann, A., Aarseth, O., Krokeide, M., Kvalheim, G., Meyer, K., and Ueland, P.M. (2016). Combined measurement of 6 fat-soluble vitamins and 26 water-soluble functional vitamin markers and amino acids in 50 μL of serum or plasma by high-throughput mass spectrometry. Anal Chem 88, 10427-436.
2. Gregory, J.F., Park, Y., Lamers, Y., Bandyopadhyay, N., Chi, Y.Y., Lee, K., Kim, S., da Silva, V., Hove, N., et al. (2013). Metabolomic analysis reveals extended metabolic consequences of marginal vitamin B-6 deficiency in healthy human subjects. PLoS One 8, e63544.