This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
FIGLU is a metabolite of 
Select and explain. 
A. Folic acid, B. Histidine, C. Tyrosine, D. Alanine
B: Histidine
Answer: B: Histidine 
Explanation: FIGLU is metabolite in the histidine metabolism. Histidine is first non-oxidatively deaminated by histidase to form urocanic acid (step1). It is then hydrated to imidazolinone propionic acid (step 2) and then hydrolyzed to formimino glutamic acid (FIGLU) (step 3). Histidine ---->FIGLU------->Formimino THF Ref: DM Vasudevan - Textbook of Biochemistry, 8th edition, page no: 297