Water-soluble vitamins thiamin

Fig. 3 Electropherogram of five water-soluble vitamines thiamine (cationic), nicotinamide (nonionic), biotin (anionic), ascorbic acid (anionic), and nicotinic acid (anionic) in 20 mM phosphate run buffer at pH 8.0.

Water-Soluble Vitamins Thiamine (B,) Precursor of the coenzyme thiamine pyrophosphate. Deficiency can cause beriberi. 

SHW has also been apphed to the separation of nutraceuticals, natural products, and biochemicals, including the water-soluble vitamins, thiamine, riboflavin, and pyidoxine (Table 18-3) without significant thermal degradation. 

Vitamins are essential nutrients that play many beneficial roles in the body [30-32,39,46-49]. Hazelnut contains both fat-soluble vitamins (A, E, and K) and water-soluble vitamins (thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folate, vitamin C, choline, and betaine)... 

Prepare 5- ig/ j,l standards (Sigma) in deionized water of each of the following water-soluble vitamins thiamine-HCl cyanocobalamin (B12) riboflavin (B2) nicotinamide pyridoxine-HCl (Bj) nicotinic acid, ascorbic acid. Prepare a mixed standard containing the seven water-soluble vitamins at respective concentrations of 6, 2, 1, 6, 6, 6, 6 Xg/ 0.1. 

Fish fat and liver (liver oil) are significant sources of fat-soluble vitamins, A and D. Also present are vitamins E (tocopherol) and K. The water-soluble vitamins, thiamine, riboflavin and niacin, occur in relatively high amounts, while others are present only in low amounts. 

Like other water-soluble vitamins, thiamin is readily lost by leaching into cooking water. Furthermore, it is unstable to light and, although bread and flour contain significant amounts of thiamin, much or all of this can be lost when baked goods are exposed to sunlight in a shop window. 

Vitamins, minerals, and electrolytes— Studies have shown that during moderate to severe stresses, more zinc, copper, magnesium, and calcium are lost in the urine. Furthermore, stress results in altered blood levels of vitamins A and C, and of zinc and iron. Also, part of the response to stress includes water and sodium retention, via veisopressin and aldosterone secretion. As for the water-soluble vitamins—thiamin, riboflavin, niacin, pyridoxine (B-6), pantothenic acid, folic acid, and vitamin C stress increases their requirement. However, no dietary recommendations are made for these nutrients for individuals under stressful situations. Still, it seems wise to supply some supplementation before deficiency symptoms appear. 

MSFIA chromatographic analysis was also applied to food analysis (Fernandez et ak, 2012), including orange juice, strawberry milkshake, and malt, for simultaneous determination of six water-soluble vitamins (thiamine, riboflavin, ascorbic acid, nicotinic... 

Generally, AA is determined individually, and only about a 10% of the published methods determine AA simultaneously with other analytes such as uric acid, glucose, fructose, dopamine, iodate, bromate, hypochlorite, thiourea, glutathione, hydrogen peroxide, acetylsalicylic acid, kojic acid, ascorbyl glucoside, paracetamol, cysteine, and other water soluble vitamins (thiamine [vitamin Bj], folic acid [vitamin B12], niacin [vitamin B3], riboflavin [vitamin B2], and pyridoxine [vitamin B ]). 

Description of Method. The water-soluble vitamins Bi (thiamine hydrochloride), B2 (riboflavin), B3 (niacinamide), and Be (pyridoxine hydrochloride) may be determined by CZE using a pH 9 sodium tetraborate/sodlum dIhydrogen phosphate buffer or by MEKC using the same buffer with the addition of sodium dodecyl-sulfate. Detection Is by UV absorption at 200 nm. An Internal standard of o-ethoxybenzamide Is used to standardize the method. 

The water-soluble vitamins comprise the B complex and vitamin C and function as enzyme cofactors. Fofic acid acts as a carrier of one-carbon units. Deficiency of a single vitamin of the B complex is rare, since poor diets are most often associated with multiple deficiency states. Nevertheless, specific syndromes are characteristic of deficiencies of individual vitamins, eg, beriberi (thiamin) cheilosis, glossitis, seborrhea (riboflavin) pellagra (niacin) peripheral neuritis (pyridoxine) megaloblastic anemia, methyhnalonic aciduria, and pernicious anemia (vitamin Bjj) and megaloblastic anemia (folic acid). Vitamin C deficiency leads to scurvy. 

The water-soluble vitamins of the B complex act as enzyme cofactors. Thiamin is a cofactor in oxidative... 

Micronutrients (mg/100 g) Water-soluble vitamins B-vitamins Thiamin 2.65 3.64 2.00... 

Water-soluble vitamins removed by hemodialysis (HD) contribute to malnutrition and vitamin deficiency syndromes. Patients receiving HD often require replacement of water-soluble vitamins to prevent adverse effects. The vitamins that may require replacement are ascorbic acid, thiamine, biotin, folic acid, riboflavin, and pyridoxine. Patients receiving HD should receive a multivitamin B complex with vitamin C supplement, but should not take supplements that include fat-soluble vitamins, such as vitamins A, E, or K, which can accumulate in patients with renal failure. 

The water-soluble vitamins generally function as cofactors for metabolism enzymes such as those involved in the production of energy from carbohydrates and fats. Their members consist of vitamin C and vitamin B complex which include thiamine, riboflavin (vitamin B2), nicotinic acid, pyridoxine, pantothenic acid, folic acid, cobalamin (vitamin B12), inositol, and biotin. A number of recent publications have demonstrated that vitamin carriers can transport various types of water-soluble vitamins, but the carrier-mediated systems seem negligible for the membrane transport of fat-soluble vitamins such as vitamin A, D, E, and K. 

In an investigation of the water-soluble vitamins in human skin,71 it was found that 15 individuals showed relatively small ranges (less than 2-fold) for vitamin B12, folic acid, and biotin about 2-fold ranges in the cases of riboflavin, niacin, and thiamine about a 4-fold range in the case of ascorbic acid, and more than a 5-fold range in the case of pantothenic acid. In another study72 it was found that the total choline content of normal skin varied in four individuals over approximately a 10-fold range 127 to 1200 ig. per gm. The variation in the free choline in the same individuals was relatively small. 

FIGURE 16 HPLC chromatogram of water-soluble vitamins using ion-pair chromatography. LC conditions and peak identification are shown in the inset.The retention times of basic analytes (pyridoxine and thiamine) are strongly dependent of the concentration of ion-pairing reagent (1-hexanesulfonate) in the mobile phase. Reprinted with permission from Reference 17. 

The SP procedure of water-soluble vitamins from multivitamin tablets is particularly challenging due to the diverse analytes of varied hydrophobicities and pfC. Water-soluble vitamins (WSVs) include ascorbic acid (vitamin C), niacin, niacinamide, pyridoxine (vitamin B ), thiamine (vitamin Bj), folic acid, riboflavin (vitamin B2) and others. While most WSVs are highly water soluble, riboflavin is quite hydrophobic and insoluble in water. Folic acid is acidic while pyridoxine and thiamine are basic. In addition, ascorbic acid is light sensitive and easily oxidized. The extraction strategy employed was a two-step approach using mixed solvents of different polarity and acidity as follows ... 

In the form in which they are consumed, many vitamins are not biologically active. For several water-soluble vitamins such as thiamine, riboflavin, nicotinic acid, pyridoxine, activation includes phosphorylation or, as is the case with riboflavin and nicotinic acid, coupling to purine or pyridine nucleotides is required. In their major known actions, water-soluble vitamins participate as cofactors for specific enzymes, whereas at least two fat-soluble... 

At low and medium doses, it is well established that the nutritional value of proteins, carbohydrates, and fats as macronutrients are not significantly impaired by irradiation, and neither the mineral bioavailability is impacted. Like all other energy depositing process, the application of ionizing radiation treatment can reduce the levels of certain sensitive vitamins. Nutrient loss can be minimized by irradiating food in a cold or frozen state and under reduced levels of oxygen. Thiamin and ascorbic acid are the most radiation sensitive, water-soluble vitamins, whereas the most sensitive, fat-soluble vitamin is vitamin E. In chilled pork cuts at the 3 kGy maximum at 0-10°C, one may expect about 35 0% loss of thiamin in frozen, uncooked pork meat irradiated at a 7 kGy maximum at —20°C approx., 35 % loss of it can be expected [122]. 

The B-group is a heterogeneous collection of water-soluble vitamins, most of which function as co-enzymes or are precursors of co-enzymes. The B-group vitamins are thiamin, riboflavin, niacin, biotin, pantothenic acid, pyridoxine (and related substances, vitamin B6), folate and cobalamin (and its derivatives, vitamin B12). 

Vitamins are chemically unrelated organic compounds that cannot be synthesized by humans and, therefore, must must be supplied by the diet. Nine vitamins (folic acid, cobalamin, ascorbic acid, pyridoxine, thiamine, niacin, riboflavin, biotin, and pantothenic acid) are classified as water-soluble, whereas four vitamins (vitamins A, D, K, and E) are termed fat-soluble (Figure 28.1). Vitamins are required to perform specific cellular functions, for example, many of the water-soluble vitamins are precursors of coenzymes for the enzymes of intermediary metabolism. In contrast to the water-soluble vitamins, only one fat soluble vitamin (vitamin K) has a coenzyme function. These vitamins are released, absorbed, and transported with the fat of the diet. They are not readily excreted in the urine, and significant quantities are stored in Die liver and adipose tissue. In fact, consumption of vitamins A and D in exoess of the recommended dietary allowances can lead to accumulation of toxic quantities of these compounds. 

The water-soluble vitamins niacinamide (a neutral compound), riboflavin (a neutral compound), niacin (an anion), and thiamine (a cation) were separated by micellar electrokinetic chromatography in 15 mM borate buffer (pH 8.0) with 50 mM sodium dodecyl sulfate. The migration times were niacinamide (8.1 min), riboflavin (13.0 min), niacin (14.3 min), and thiamine (21.9 min). What would the order have been in the absence of sodium dodecyl sulfate Which compound is most soluble in the micelles ... 

Nearly all the water-soluble vitamins are heterocyclic compounds. Among the first to be isolated was thiamine (vitamin Bi) (62), deficiency of which causes degenerative changes in the nervous system, including the multiple peripheral neuritis characteristic of beriberi. Thiamine deficiency can arise from decomposition of the vitamin by bacteria in the gut. In mammalian metabolism the hydroxy group of thiamine is esterified to give cocarboxylase (thiamine pyrophosphate) which catalyzes the decarboxylation of a-keto acids to aldehydes, acyloins or acids, and their transformation into acyl phosphates. 

As indicated in Table 14.1, the water-soluble vitamins, e.g., thiamine, vitamin Bi2, and vitamin C, are susceptible to loss by heat processing of milk (Bender 1978 Harper 1976). UHT sterilization and... 

Why do we need vitamins Early clues came in 1935 when nicotinamide was found in NAD+ by H. von Euler and associates and in NADP+ by Warburg and Christian. Two years later, K. Lohman and P. Schuster isolated pure cocarboxylase, a dialyz-able material required for decarboxylation of pyruvate by an enzyme from yeast. It was shown to be thiamin diphosphate (Fig. 15-3). Most of the water-soluble vitamins are converted into coenzymes or are covalently bound into active sites of enzymes. Some lipid-soluble vitamins have similar functions but others, such as vitamin D and some metabolites of vitamin A, act more like hormones, binding to receptors that control gene expression or other aspects of metabolism. 

The fat-soluble vitamins are A, D, E, and K. The water-soluble vitamins are thiamine (vitamin Bj), riboflavin, nicotinic acid (niacin) and nicotinamide, pyridoxine (vitamin B6), pantothenic acid, biotin, para-aminobenzoic acid, choline, inositol, and other lipotropic agents, ascorbic acid (vitamin C), the riboflavonoids, folate, and vitamin B12 (see Figure 66.1 and Figure 66.2, and Table 66.1). 

The first water-soluble vitamin discovered was called vitamin B to distinguish it from vitamin A. Later other B vitamins were discovered and given names such as vitamin B2, B2, etc. Now the specific chemical names are used. In distinction to the fat-soluble vitamins, the water-soluble vitamins are not absorbed with fats and they are not stored in appreciable quantities in the body (with the possible exception of B12 and thiamin). Excesses of these vitamins are excreted rapidly in urine, requiring a constant dietary supply. 

Many cells require media supplemented with complex B vitamins, while other vitamins are presumably supplied by the addition of serum to culture media. Nevertheless, when serum-free media are employed, not only the water-soluble vitamins should be provided, but also the lipid-soluble ones, such as biotin, folic acid, niacin, panthotenic acid, thiamine, and ascorbic acid, as well as the vitamins B12, A, D, E, and K. 

Water-soluble vitamins. Water-soluble vitamins include vitamin C, and those of the B-complex group biotin, folate, niacin, pantothenic acid, riboflavin, thiamine, vitamin Bg and vitamin B12. They function mainly as coenzymes and prosthetic groups. 

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