FIGLU is intermediate product of metabolism of

Ans. a (Histidine) (Ref. Harper's Biochemistry 28th/pg. 16).# Figlu or N-formimino glutamate - is formed during catabolism of Histidine.# During process, transfer of the formimino group of Figlu to tetrahydrofolate (H4 folate) forms glutamine. In folic acid deficiency, this reaction is partially or totally blocked and figlu is excreted in the urine.# Excretion of "Figlu" following a test dose of Histidine therefore provides a diagnostic test for folic acid deficiency.# Figlu test and Histidine test: Formimino-glutamate (figlu), a catabolite of Histidine, transfers its formimino group to H4- folate to form N5 formimino-H4 folate.In folate deficiency, Figlu will accumulate after oral challenges with Histidine.Histidine:# maximum buffering capacity- Maximum pH regulation seen# has no charge at neutral pH- proteinate and deproteinate at neutral pH# In folic acid deficiency, group transfer to THF is impaired and Figlu is excreted.