Nicotinic acid pyridoxine

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 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... 

Organic supplements Small amount of vitamins (myo-inositol, thiamine, nicotinic acid, pyridoxine, and so on.), amino acids (usually omitted but sometimes used with advantage), and other undefined supplements (meat, malt, and yeast extract, and protein hydrolysates, and so on.). 

At higher ethanol concentrations the intracellular alcohol interferes with membrane organization, increasing its fluidity and permeability to ions and small metabolites and inhibiting transport of nutrients. Especially Ca and Mg ions are able to increase the plasma membrane stability. It has been demonstrated that incorporation of unsaturated fatty acids and/or sterol(s) as well as proteolipids into cellular membrane of yeasts helps to alleviate ethanol tolerance. For the synthesis of the unsaturated fatty acids the presence of traces of oxygen under fermentation conditions is required. Further to Ca and Mg ions, other trace elements such as Co, Cu, Mn and Zn " and vitamins, e.g. pantothenate, thiamine, riboflavin, nicotinic acid, pyridoxine, biotin, folic acid and inositol, are essential for the growth and ethanol production by yeasts. 

Linoleic acid Magnesium phosphate tribasic Manganese citrate (ous) Manganese sulfate (ous) Nicotinic acid Pyridoxine HCI Retinol Retinyl acetate Riboflavin-5 -phosphate sodium Thiamine HCI... 

At the present time we can only say that, for the continued growth of E. histolytica in vitro, cholesterol is needed. Cholesterol is inactive in promoting growth in the absence of the B vitamins (thiamine, robiflavin, nicotinic acid, pyridoxine, pantothenic acid, p-aminobenzoic acid, inositol, and choline were used ), and living organisms must be present (bacteria of various kinds or Trypanosoma cruzi ). In addition a rather low oxidation-reduction potential is essential for continued growth. ... 

Vitamins of the B-group (vitamins Bi and B2, nicotinic acid, pyridoxine and pantothenic acid) are present in various beers, often in significant amounts. 

Vitamin Ba (pyridoxine, pyridoxal, pyridoxamine) like nicotinic acid is a pyridine derivative. Its phosphorylated form is the coenzyme in enzymes that decarboxylate amino acids, e.g., tyrosine, arginine, glycine, glutamic acid, and dihydroxyphenylalanine. Vitamin B participates as coenzyme in various transaminations. It also functions in the conversion of tryptophan to nicotinic acid and amide. It is generally concerned with protein metabolism, e.g., the vitamin B8 requirement is increased in rats during increased protein intake. Vitamin B6 is also involved in the formation of unsaturated fatty acids. 

The usable range for T. pyriformis is from 0.3-300 mug/ml. The organism utilizes pyridoxal, pyridoxamine pyridoxine, and pyridoxal-5-phosphate. Pyridoxamine + pyridoxal yielded the best growth approximately 120 times more pyridoxine is required to yield the same growth as pyridoxamine (Fig. 4). As with nicotinic acid and its amide, when these compounds are added together in the same concentration, the increment of growth is less than the sum of the individual increments. Upon an intramuscular load dose of 100 mg of pyridoxine, peak vitamin Bs levels are reached 2 hours after injection. The curves for 4 normal individuals are illustrated in Fig. 5. 

Group-transfer reactions often involve vitamins3, which humans need to have in then-diet, since we are incapable of realizing their synthesis. These include nicotinamide (derived from the vitamin nicotinic acid) and riboflavin (vitamin B2) derivatives, required for electron transfer reactions, biotin for the transfer of C02, pantothenate for acyl group transfer, thiamine (vitamin as thiamine pyrophosphate) for transfer of aldehyde groups and folic acid (as tetrahydrofolate) for exchange of one-carbon fragments. Lipoic acid (not a vitamin) is both an acyl and an electron carrier. In addition, vitamins such as pyridoxine (vitamin B6, as pyridoxal phosphate), vitamin B12 and vitamin C (ascorbic acid) participate as cofactors in an important number of metabolic reactions. 

Two vitamins, nicotinamide and pyridoxine (vitamin B6), are pyridine derivatives. Nicotinamide participates in two coenzymes, coenzyme I (65 R = H) which is known variously as nicotinamide adenine dinucleotide (NAD) or diphosphopyridine nucleotide (DPN), and coenzyme II (65 R = P03H2) also called triphosphopyridine nucleotide (TPN) or nicotinamide adenine dinucleotide phosphate (NADP). These are involved in many oxidation-reduction processes, the quaternized pyridine system acting as a hydrogen acceptor and hydrogen donor. Deficiency of nicotinamide causes pellagra, a disease associated with an inadequately supplemented maize diet. Nicotinic acid (niacin) and its amide are... 

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). 

A deficiency syndrome is not well-defined in humans. Since pyridoxine deficiency often produces nicotinic acid deficiency, pellagra-like clinical manifestations may occur.29 The recommended daily allowance is 1.5 to 2 mg.112... 

Saareks V, Mucha 1, Sievi E, and Riutta A (1999) Nicotinic acid and pyridoxine modulate arachidonic acid metaholism in vitro and ex vivo in man. Pharmacology and Toxicology 84,274-80. 

P13. Prinsloo, J. G., Joubert, C. P., de Lange, D. J., du Plessis, J. P., and Hojby, T., The conversion of tryptophan to nicotinic acid in South African Bantu pellagrins with special reference to the role of pyridoxine and riboflavine. Proc. Nutr. Soc. S. Africa 3, 66-71 (1962) Ghem. Abstr. 60, 16265 (1964). 

The potential of PBI LC-MS in the analysis of various vitamins was explored by Careri et al. [99-100]. The fat-soluble vitamins A, D, and E were analysed in food and multivitamin preparations [99]. Absolute detection limits in SIM mode were 0.6-25 ng after fast leversed-phase separation using a 97% aqueous methanol as mobile phase. Mass spectra in El, positive-ion and negative-ion Cl were obtained and discussed. The mass-spectral and quantitative performance of PBI LC-MS in the analysis of eleven water-soluble vitamins was also explored [100]. Detection limits were determined in SIM mode under positive-ion Cl, and were below 15 ng for ascorbic acid, nicotinamide, nicotinic acid, and pyridoxal, around 100 ng for dehydroascorbic acid, panthothenic acid, and thiamine, and above 200 ng for biotin, pyridoxamime, and pyridoxine. Riboflavine was not detected. 

Although the water-soluble vitamins are structurally diverse, they are put in a general class to distinguish them from the lipid-soluble vitamins. This cla.ss includes the B-complex vitamins and ascorbic acid (vitamin C). The term B-complex vitamins usually refers to thiamine, riboflavin, pyridoxine. nicotinic acid, pantothenic acid, hiotin. cyanocobalamin. and folic acid. Dietary deficiencies of any of the B vitamins commonly are complicated by deftciencies of another mem-ber(s) of the group,. so treatment with B-complex preparations is usually indicated. 

Pyridoxine Hydrochloride, USP. Pyridoxine hydrochloride.. S-hydroxy-6-methyl-3.4-pyridinedimethanol hydrochloride. vitamin B, hydrochloride, rat antidermatitis factor. is a white, odorless, crystalline substance that is soluble l .S in water and 1 100 in alcohol and in.soluble in ether. It is relatively. stable to light and air in the solid form and in acid solutions at a pH no greater than S. at which pH it can be autoclaved at IS pounds at I20°C for 20 to 30 minutes. Pyridoxine is unstable when irradiated in aqueous solution.s at pH 6.8 or above. It is oxidized readily by hydrogen peroxide and other oxidizing agents. Pyridoxine is as stable in mixed vitamin preparations as riboflavin and nicotinic acid. A 1% aqueous solution has a pH of 3. The pK i values fur pyridoxine. pyridoxal. and pyridoxamine are S.OO. 4.22. and 3.40. respectively, and their pK 2 values are 8.96. 8.68. and 8.05. respectively. 

Dose for deficiency Thiamine 30-60 mg/d Riboflavin 5-25 mg/d Prophylactic 3 mg/d Nicotinic acid or niacin Prevention 5-20 mg/d Deficit 50-100 mg/d Pellagra 300-500 mg in three divided doses Hyperlipidemia 1-2 g/d in three divided doses Pyridoxine 25-100 mg/d Isoniazid therapy prophylaxis 25-20 mg/d Peripheral neuritis 50-200 mg/d... 

Fig. 8-87. Analysis of water-soluble vitamins. - Separator column Spherisorb ODS 2 (5 pm) eluent (A) 0.1 mol/L KOAc (pH 4.2 with HOAc), (B) water/methanol/acetonitrile (50 10 40 v/v/v) gradient linear, 6% B in 30 min to 100% B flow rate 2 mL/min detection UV (254 nm) injection volume 50 pL solute concentrations 5 nmol each of ascorbic acid (1), nicotinic acid (2), thiamine (3), pyridoxine (4), nicotinic add amide (5), p-aminobenzoic add (6), cyanocobala-mine (7), and riboflavine (8).

It was quickly established by many techniques (381, 430, 782, 817, 957, and review 170) that the conversion of tryptophan to nicotinic acid occurred in body tissues and was not due (except perhaps in part in exceptional circumstances cf. 170) to intestinal bacteria. Moreover nutritional studies showed that kynurenine was probably also a precursor of nicotinic acid (457) and that kynurenine and xanthurenic acid excretion were increased in pyridoxine deficiency (21). 

By 1950 the outline of the main pathway for tryptophan metabolism was therefore established, and it was becoming apparent that the over-all conversion of tryptophan to nicotinic acid was markedly reduced in many B-vitamin deficiencies. Thus this occurred in pyridoxine deficiency (50, 387, 732, 784), riboflavin deficiency (387,455, 675), and thiamine deficiencj (455, 675) but not in pantothenate or folic acid deficiencies (455). 

---