Three different approaches, including the commonly used acid digestion, were compared for the efficient extraction of very low concentrations of riboflavin (vitamin B2) from casein. An extraction method that used pepsin to release riboflavin was the most efficient. The pepsin extraction method was then further optimized using a factorial design to yield the maximum amount of riboflavin. The enz...

BACKGROUND: Brown-Vialetto-Van Laere syndrome (BVVLS) is a rare, treatable neurodegenerative disorder with variable clinical presentation, caused by mutations in three different riboflavin transporter genes. CASE: An 11-year-old-boy presented respiratory insufficiency and rapidly progressive muscle weakness. He was the fifth child of consanguineous marriage medical history hearing loss. peri...

The biosynthesis of one riboflavin molecule requires one molecule of GTP and two molecules of ribulose 5-phosphate as substrates. GTP is hydrolytically opened, converted into 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione by a sequence of deamination, side chain reduction and dephosphorylation. Condensation with 3,4-dihydroxy-2-butanone 4-phosphate obtained from ribulose 5-phosphate leads to...

BACKGROUND/OBJECTIVES Physical exercise promotes energy producing pathways requiring thiamin and riboflavin as a coenzyme. Therefore, this study investigated the effects of regular exercise training on urinary excretion of thiamin and riboflavin. MATERIALS/METHODS Fifty rats were randomly assigned to one of two groups: non-exercise training (NT, n = 25) and regular exercise training (ET, n = ...

background and aims: despite the screening of blood donors, blood transfusion represents an ideal port of entry for blood-borne infection. blood-borne pathogen transmission has been a concern since the earliest days of transfusion. the blood product of platelet (plt) concentrates is still faced with the risk of bacterial and viral contaminations. pathogen inactivation technologies offer a proac...

1. Refection, resulting in an increased supply of riboflavin to riboflavin-deficient rats through coprophagy, was demonstrated on a sucrose-based diet when sensitive biochemical tests of riboflavin status were employed: these included measurements of NAD(P)H2:glutathione oxidoreductase (EC 1.6.4.2); succinate:(acceptor) oxidoreductase (EC 1.3.99.1) and NADH:(acceptor) oxidoreductase (EC 1.6.99....

BACKGROUND High cell density cultures of Pichia pastoris grown on methanol tend to develop yellow colored supernatants, attributed to the release of free flavins. The potential of P. pastoris for flavin overproduction is therefore given, but not pronounced when the yeast is grown on glucose. The aim of this study is to characterize the relative regulatory impact of each riboflavin synthesis gen...

The dependence of glycolate oxidase apoprotein (apoGO) activity on flavin analogs was surveyed in 9 higher plants from 7 families. Activities of all apoGOs depended not only on flavin mononucleotide (FMN) but also on flavin adenine dinucleotide (FAD), but not on riboflavin. The kinetic analysis showed that FMN was the optimum cofactor for apoGO from leaves of Brassica campestris. In plant kingd...

The dairy starter bacterium Lactococcus lactis has the potential to synthesize both folate (vitamin B11) and riboflavin (vitamin B2). By directed mutagenesis followed by selection and metabolic engineering we have modified two complicated biosynthetic pathways in L. lactis resulting in simultaneous overproduction of both folate and riboflavin: Following exposure to the riboflavin analogue roseo...

We describe a method for determining urinary riboflavin by "high-pressure" liquid chromatography, with fluorometric detection. An aliquot of a 24-h urine specimen is injected directly into the chromatograph and the natural fluorescence of riboflavin is measured as the compound is eluted. Interference from other fluorophores is obviated because of differing retention times. Urinary components ot...