Xanthurenic acid is the metabolite in the metabolism of
3-Hydroxy Kynurenine is one of the intermediate in tryptophan catabolism, which gets conveed to next intermediate and this conversion requires vitamin B6/ PLP. So, in B6 deficiency, this reaction does not occur and 3-Hydroxy Kynurenine is diveed to form alternate metabolite, Xanthurenic acid (See fig), which is excreted in urine
Uric acid
Xanthine
Tryptophan
Uronic acid
Classification and metabolism of amino acids