Under normal conditions of growth, riboflavin is synthesized by all higher plants and is utilized as a prosthetic group by various flavoprotein enzymes (12). Pound and Welkie (11) observed the presence of a yellow pigment in the nutrient solution of tobacco plants grown in the absence of iron. Physical and chemical tests indicated that the pigment was riboflavin, and it was suggested that the d...

BACKGROUND Nightblindness affects 16-52% of pregnant women in areas of Nepal and in some cases persists after vitamin A treatment. Iron and riboflavin affect vitamin A utilization and photoreceptor function, respectively, and pilot data in the study population showed a high prevalence of iron and riboflavin deficiencies. OBJECTIVE The objective was to assess the effect of supplemental iron an...

The concentrations of many of the vitamins or their natural derivatives in blood serum and cells reflect the relatively recent intake of the particular dietary essential (e.g., ascorbic acid). Such a relationship between blood level and intake has led to the usefulness of chemical analytical methods for the evaluation of nutritional status. However, there is, at present, insufficient informatio...

Flavin reductase catalyzes the reduction of free flavins by NAD(P)H. As isolated, Escherichia coli flavin reductase does not contain any flavin prosthetic group but accommodates both the reduced pyridine nucleotide and the flavin substrate in a ternary complex prior to oxidoreduction. The reduction of riboflavin by NADPH catalyzed by flavin reductase has been studied by static and rapid kinetic...

PURPOSE To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. H...

Riboflavin and the adenosine derivative 5'-bromo-5'-deoxyadenosine form a crystalline 1:1 intermolecular complex, the structure of which has been solved by x-ray diffraction analysis. The adenine ring is found to be joined by two hydrogen bonds to the uracillike end of the riboflavin isoalloxazine ring. In addition, the riboflavin and the adenosine molecules associate through the formation of s...

1. Riboflavin deficiency at two levels of severity was produced in weanling rats by feeding deficient diets for 6 weeks and using neck collars to prevent coprophagy. The severity of deficiency was monitored by growth, liver flavin levels and the activation coefficient of erythrocyte glutathione oxidoreductase (NAD(P)H) (EC 1 . 6 .4 .2 ) . Control groups, receiving the same diet with ample added...

BACKGROUND Although organoboronic acids are efficient high-throughput sugar sensors, they have not been pursued for gut permeability studies. A modification of the lactulose/mannitol assay is described by which small intestinal permeability is assessed at the time of urine collection using a lactulose/riboflavin ratio. METHODS Volunteers ingested 50mg riboflavin and either 5 g mannitol or 10 ...

Dodecins, a group of flavin-binding proteins with a dodecameric quaternary structure, are able to incorporate two flavins within each of their six identical binding pockets building an aromatic tetrade with two tryptophan residues. Dodecin from the archaeal Halobacterium salinarum is a riboflavin storage device. We demonstrate that unwanted side reactions induced by reactive riboflavin species ...

While it is well recognized that riboflavin accumulates in breast milk as an essential vitamin for neonates, transport mechanisms for its milk excretion are not well characterized. The multidrug efflux transporter ABCG2 in the apical membrane of milk-producing mammary epithelial cells (MECs) is involved with riboflavin excretion. However, it is not clear whether MECs possess other riboflavin tr...