Riboflavin metabolism can happen in two different sets of reactions a) Guanosine triphosphate reacts with water through a GTP cyclohydrolase resulting in the release of formic acid, pyrophosphate and 2,5-Diamino-6-(1-D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate. The latter compound then reacts with a NADH dependent 2,5-diamino-6-(ribosylamino)-4(3H)-pyrimidinone 5'-phosphate reductase resulting in the release of NAD and 2,5-Diamino-6-(1-D-ribitylamino)pyrimidin-4(3H)-one 5'-phosphate. The latter compound reacts through a tRNA pseudouridine synthase 8 / 2,5-diamino-6-(5-phospho-D-ribitylamino)-pyrimidin-4(3H)-one deaminase resulting in the release of 5-Amino-2,6-dioxy-4-(5'-phospho-D-ribitylamino)pyrimidine. b)Ribulose 5-phosphate reacts with 3,4-dihydroxy 2-butanone 4-phosphate synthase resulting in the release of formic acid and 1-Deoxy-L-glycero-tetrulose 4-phosphate. The latter compound reacts with a 5-Amino-6-ribitylamino uracil through a 6,7-dimethyl-8-ribityllumazine synthase resulting the release of 6,7-dimethyl-8-(D-ribityl)lumazine. The latter compound reacts with a riboflavin synthase resulting in the release of 5-Amino-6-ribitylamino uracil and Riboflavin. The Riboflavin reacts with an ATP driven riboflavin synthase resulting in the release of ADP and Flavin mononucleotide. The latter compound reacts with an ATP driven FAD synthetase resulting in the release of pyrophosphate and FAD.

Riboflavin Metabolism References