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Riboflavin appearance

Ohkawa, H., Ohishi, N., and Yagi, K. (1983). New metabolites of riboflavin appear in human urino. J. Biof. Cheat. 258,5623-5628. [Pg.685]

Free riboflavin appears to be present to a significant extent in the retina of certain animals and fishes, in milk, and in the urine. The findings of Bessey, Lowry, and Love indicate that riboflavin, like the other B vitamins, occurs mostly in bound forms, FAD being the major constituent. The FAD content varies from 90% of the total riboflavin content of the muscle to 70% in the kidney. The remainder occurs mainly as FMN, with free riboflavin being present in only trace amounts. [Pg.346]

Holding on a steam table—Losses of vitamin C, thiamin, and riboflavin appear to increase with the length of time that vegetables are kept warm on a steam table. [Pg.1042]

Manufacturing procedures of riboflavin have also appeared using Saccharomjces bacteria, eg, fermentation with a purine-independent S. reverse mutant (61) and with S. cerevisiae NH-268 (62) produced 2.79 g/L and 4.9 g/L, respectively. [Pg.78]

Interestingly, exceptions are possible. Stewart et al. [81] reported that the effect of magnesium stearate concentration on the dissolution of a model low-dose drug, riboflavin, from capsules was dependent in some manner on the type of filler. Soluble fillers exhibited the anticipated prolonged times with increasing lubricant levels. However, the trends with insoluble fillers were less predictable. In some cases insoluble fillers were only slightly affected by the concentration of magnesium stearate. For others, such as microcrystalline cellulose, there appeared to be an ideal intermediate concentration of lubricant at which the dissolution rate was maximized. [Pg.366]

Niacin, riboflavin, pantothenic acid and vitamin B6 contents are greatly increased in tempeh during fermentation, whereas thiamin exhibits no significant change. H. oligosporus appears to have a great synthetic capacity for niacin, riboflavin, pantothenic acid, and vitamin B, but not for thiamin. [Pg.62]

Riboflavin needs have been found to vary with different strains of white Leghorn chickens,56, 57 and there appears to be a sex difference in that females require less and thus show greater resistance to riboflavin deficiency. [Pg.199]

The ionisation state of molecules in the solution state appears to be an important variable in photodegradation mechanisms. A recent pubhcation on riboflavin oral liquid preparations shows that the formulation is most photostable at pHs between 5 and 6, where the non-ionised form predominates [78]. The rate of photolysis increase 80-fold at pH 10.0, owing to increased redox potential. Conversely, at pH 3.0, the increased photolysis is associated with the excited singlet state, in addition to the triplet state. [Pg.35]

Among the naturally occurring chiral substances, tested in the resolution of helicenes, riboflavine, and several nucleotides and nucleosides have appeared successful. Some results are given in Table 8. [Pg.89]

The same authors (G8, G7) also found very substantial decreases in riboflavin (approx. 80%), and niacin (P9) fared little better. When mixtures were irradiated unusual events occurred. Riboflavin and ascorbic acid were each protected by niacin. Addition of cystine or cysteine apparently sensitized the niacin (P10). Since initial rates were not given, and the doses were considerably above the oxygen breakpoint (Sec. IIIA2), no mechanistic interpretation is possible. There also appears to be some doubt about the reliability of the colormetric assay used by these workers. [Pg.406]

More than one century ago a yellow, fluorescent pigment was isolated from whey by Blyth In the subsequent years yellow pigments were extracted from various biological materials. Depending either on the source of isolation or the physical appearance, these natural products were named e.g. lactochrome , lycochrome , ovoflavin , lactoflavin , hepatoflavin , or verdoflavin . Later, it became evident that all these compounds are riboflavin (vitamin B2). [Pg.72]

Riboflavin deficiency is not associated with a major human disease, although it frequently accompanies other vitamin deficiencies. Deficiency symptoms include dermatitis, cheilosis (fissuring at the corners of the mouth), and glossitis (the tongue appearing smooth and purplish). [Pg.379]

While the mechanism for the formation of (35) has not been determined, an internal oxidation-reduction of the ribityl group (similar to that catalyzed by methylglyoxal synthetase) to afford the free diketone (38) which reacts with a second molecule of (32), appears plausible. In support of this it has been shown (82JA3754) that label from [1-3C]ribose is incorporated at the C-5 of riboflavin (corresponding to the 6-methyl of 33) and not at C-8. [Pg.93]

In general, vitamins appear to be at least as stable during UHT processing as during conventional pasteurization (Mehta 1980). Levels of the fat-soluble vitamins A, D, and E, as well as those of the water-soluble vitamins, riboflavin, nicotinic acid, pantothenic acid, and biotin in milk, are not decreased by UHT processing. Furthermore, no loss of... [Pg.388]

Luminescent bacteria all appear to obtain light from a riboflavin-5 -phosphate dependent oxygenase, which converts a long-chain aldehyde (usually n-tetradecanal) to a carboxylic acid (Eq. 23-47). Here FH2 is the riboflavin 5 -P, which is thought to be supplied by a flavin reductase.6793... [Pg.1346]

Structures of the vitamin riboflavin (a) and the derived flavin coenzymes (b). Like NAD+ and NADP+, the coenzyme pair FMN and FAD are functionally equivalent coenzymes, and the coenzyme involved with a given enzyme appears to be a matter of enzymatic binding specificity. The catalytically functional portion of the coenzymes is shown in red. [Pg.207]

A note on the rapid conversion of fevo-kynurenine to anthranilic acid, and the conjugation of the latter with glucuronic acid by riboflavin-deficient rat-liver and rat-kidney slices, has recently appeared.148... [Pg.220]

Lumichrome (Figure 10.1), a water-soluble degradation product of riboflavin,157 appears to be the first characterized gregarious (produced by conspecifics) cue for induction of metamorphosis of a marine invertebrate. Lumichrome is exuded into aqueous media from cultures of larvae of the ascidian Halocynthia roretzi, and was also found in the eggs, gonads, and tunic of the adults following extraction in methanol.157 Metamorphosis of larvae was induced by purified lumichrome... [Pg.368]

Deger, D., Ashoor, S.H. 1987. Tight induced changes in taste, appearance, odor and riboflavin content of cheese. J. Dairy Sci. 70, 1371-1376. [Pg.588]

Subsequently, the functions of the vitamin were better established and requirements for the vitamin were set. Riboflavin is an Integral part of two coenzymes, flavin-5 -phosphate (FMN) and flavin adenine dinucleotide (FAD), which function in oxidation/reductlon reactions. Indeed, riboflavin is an enzyme cofactor which is necessary in metabolic processes in which oxidation of glucose or fatty acid is used for production of adenosine triphosphate (ATP) as well as in reactions in which oxidation of amino acids is accomplished. The minimum requirement for riboflavin has been established as that amount which actually prevents the signs of deficiency. A range of intakes varying from 0.55 to 0.75 mg/day of riboflavin has been established as the minimum amount which is required to prevent appearance of deficiency signs. [Pg.80]

Nitrobenzene reductase activity has been detected in the fat body, gut, and Malpighian tubules of the Madagascar cockroach, G. portentosa (Rose and Young, 1973). Anaerobic conditions are essential for activity. The enzymes in the microsomes are strongly NADH dependent, whereas those in the soluble fraction are strongly NADPH dependent. Activity is enhanced by the addition of flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN) or riboflavin. It appears that the true substrate for the nitroreductase is FMN and that the reduction of the nitro compounds occurs nonenzymatically (Figure 8.15). Similar results are obtained using azofuchsin as substrate. [Pg.152]


See other pages where Riboflavin appearance is mentioned: [Pg.111]    [Pg.15]    [Pg.702]    [Pg.111]    [Pg.15]    [Pg.702]    [Pg.260]    [Pg.45]    [Pg.70]    [Pg.110]    [Pg.80]    [Pg.26]    [Pg.52]    [Pg.202]    [Pg.29]    [Pg.150]    [Pg.209]    [Pg.39]    [Pg.921]    [Pg.1549]    [Pg.60]    [Pg.91]    [Pg.92]    [Pg.93]    [Pg.783]    [Pg.795]    [Pg.1462]    [Pg.260]    [Pg.619]    [Pg.140]    [Pg.270]   
See also in sourсe #XX -- [ Pg.93 ]




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Appearance

Riboflavine

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