This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': 'Xanthurenic acid, accumulation occurs due to pyridoxine deficiency, is a metabolite of which amino acid? \nSelect and explain. \nA. Tyrosine, B. Phenylalanine, C. Tryptophan, D. Alanine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In the metabolism of Tryptophan, Kynurenine is an intermediate step.T his step is catalyzed by Kynureninase enzyme which is Vitamin B6 dependent. When there is Vitamin B6 deficiency this pathway is blocked. Hence accumulated Kynurenine is shunted to Xanthurenic acid.', 'role': 'assistant'}]