Biochemistry

II ,C о I 4 HCOH I HCOH Isoal loxazine system Ribitol-ribite I CHjOH J Riboflavin The riboflavin molecule is based on the heterocyclic compound isoalloxazine (a combination of a benzene, pyrazine and pyrimidine base, to which in the ninth position aribitol pentatomic alcohol is attached). The chemical name "riboflavin" reflects the presence of a ribitol residue in the molecule and yellow color of the oxidized form of the drug. Riboflavin is chemically unstable, easily destroyed by boiling in neutral and alkaline solutions. It is very sensitive to light, ultraviolet rays and is relatively easy to undergo reverse recovery, attaching hydrogen at the site of double bonds and turning into a colorless leukoform. The ability of riboflavin to easily oxidize and recover is explained by its participation in cellular metabolism. Biological role. A biological effect of riboflavin is associated with its participation in tissue respiration. In the form of phosphoric ether or as part of even more complex compounds, in particular with nucleotides (flavin mononucleotide (FMN), flavinadeninedinucleotide (FAD), riboflavin is a coenzyme of oxidorcductases. They carry out a number of important reactions in the body: oxidation of a-amino acids, aldehydes, monoamines, purine bases, fatty acids, carbohydrates, etc. A number of enzymes containing riboflavin are involved in the exchange of other vitamins, for example, pyridoxine, choline, folic and pantothenic acids. It has a positive effect on the skin functions, mucous membranes, stimulates hematosis, promotes visual acuity, normal fetal development during pregnancy, and the growth of children. 249