Hydroxypyruvic acid (β-Hydroxypyruvic acid) is an intermediate in the metabolism of glycine, serine and threonine. Hydroxypyruvic acid is a substrate for serine-pyruvate aminotransferase and glyoxylate reductase/hydroxypyruvate reductase. Hydroxypyruvic acid is involved in the metabolic disorder which is the dimethylglycine dehydrogenase deficiency pathway. IC50 & Target: IC50: intermediate; substrate In Vivo: Hydroxypyruvic acid (intravenous injection; 100 mg/ml; slowly over 10 min) increases the 5-h urinary oxalate and glycolate excretion to 0.68% (6.56 μmol) and 0.53% (5.10 μmol) in control rats, in addition, it increases to 2.43% (23.36 μmol) and 0.79% (7.59 μmol) of the dose in the vitamin-B6-deficient rats^[1].