Xanthurenic acid

Xanthurenic acid, or xanthurenate, is a chemical shown to induce gametogenesis of Plasmodium falciparum, the parasite that causes malaria. It is found in the gut of the Anopheles mosquito.

Xanthurenic acid is a metabolic intermediate that accumulates and is excreted by pyridoxine (vitamin B₆) deficient animals after the ingestion of tryptophan.

Xanthurenic acid is suspected to be an endogenous agonist for Group II metabotropic glutamate receptors in humans. It is also known to be a potent VGLUT inhibitor, thereby preventing the movement of glutamate from the cytoplasm into synaptic vesicles, an action that it mediates via competitive blockade of vesicular glutamate transporters (K_i = 0.19 mM). In 2015 researchers reported a marked reduction of xanthurenic acid levels in the serum of patients with schizophrenia, describing this phenomenon as a potential trait marker for schizophrenia.