Structure of homocyseine

 

Part I:--Homocysteine   is metabolized through two pathways: Remethylation and  trans-sulfuration .

A) Remethylation to methionine requires folate and B12  as co enzymes while  B)  transsulfuation  requires pyridoxal -5  phosphate   , the B12  co enzyme for its  conversion to cysteine .

Therefore in poor men and women  simply F acid suppl won’t do as to normalize the blood homocysteine level we must   supplement B12 and B6 as well .But seldom this is done in clinical practice . Pyrilong F  , A-Zcap, Becadexamin however contains Both F acid, B6  and Vit B6 .

What does F.  acid and B 12 do in the body in methyl donor process?  These are principally methyl donors to any molecules. It is a homologue of the amino acid cysteine, differing by an additional methylene bridge (-CH₂-). It is biosynthesized from methionine by the removal of its terminal C^ε methyl group. In the body, homocysteine can be recycled  into methionine or converted into cysteine with the aid of certain B-vitamins. Methionine is a sulfur-containing amino acid which enters the body through dietary proteins, is used in forming proteins in the body, and is the precursor (through the methionine cycle) of the sulfur-containing amino acids homocysteine, cysteine, and taurine. The transsulfuration pathway connects methionine and glutathione biosynthesis. In the methionine cycle, methionine forms S-adenosylmethionine which serves as a methyl donor, generating S-adenosyl homocysteine. This is converted to homocysteine, converted back