Nicotinic acid aspects

The term niacin refers to nicotinic acid (pyridine-3-carboxyhc acid), its amide nicotinamide, and derivatives that show the same biological activity as nicotinamide. A distinction between the two primary vitamin forms has to be considered, however, when considering some aspects of their metabolism and especially their different pharmacological actions at high doses. Structures of both vitamers and the two coenzyme forms containing the nicotinamide moiety are given in Figure 30-23. 

Figure 2 NAD biosynthesis subsystem diagram. Major functional roles are shown by 4-6 letter abbreviations (explained in Table 1) over the colored background reflecting the key aspects or modules (pathways) that comprise NAD biosynthesis in various species. Catalyzed reactions are shown by solid straight arrows, and corresponding intermediate metabolites are shown as abbreviations within ovals Asp, L-aspartate lA, Iminoaspartate Qa, quinolinic acid Nm, nicotinamide Na, nicotinic acid NaMN, nicotinic acid mononucleotide NMN, nicotinamide mononucleotide RNm, N-ribosyInicotinamide NaAD, nicotinate adenine dinucleotide NAD, nicotinamide adenine dinucleotide NADP, NAD-phosphate Trp, tryptophan FKyn, N-formylkynurenine Kyn, kynurenine HKyn, 3-hydroxykynurenine HAnt, 3-hydroxyanthranilate and ACMS, a-amino-/3-carboxymuconic semialdehyde. Unspecified reactions (including spontaneous transformation and transport) are shown by dashed arrows.

Evans WC (1975) Thiaminases and their effects on animals. Vitam Horm 33 467-504 Faivre M, Saif N, Barral C (1975) Accidents de la vitamine Bi2- Lyon Med 233 897-993 Feinberg SM (1948) Anaphylactic shock due to nicotinic acid. NY State J Med 48 635 Fisher AA (1975) Contact dermatitis in surgeons. J Dermatol Surg 1 63-67 Fishman L, Goldstein M (1968) Vitamins in dermatology. J Med Assoc Ga 57 342-346 Folkers K (1969) Survey on the vitamin aspects of coenzyme Q. Int J Vitam Nutr Res 39 334-352... 

Pelner L (1947) Anaphylaxis to the injection of nicotinic acid (niacin), successful treatment with epinephrine. Ann Intern Med 26 290-304 Pepys J (1975) Skin tests in diagnosis. In Clinical aspects of immunology, 3rd edn. Black-well, Oxford... 

The oxidation of appropriate alkylpyridines and quinolines continues to represent the most important process for the manufacture of nicotinic acid. All aspects of the field have seen continuing development, and a Czech review is available. A general developmental study comparing seven oxidizing agents on a quantitative basis has also appeared. ... 

There are numerous sources of niacin that are essential and these include poultry, fish (tuna, salmon), meat (beef), yeast, legumes, milk and fortified eereals. In addition, niacin is naturally occurring in tiny amounts and the human body can make nicotinic acid from the metabolism of dietary tryptophan (Vosper 2009). The body requires tryptophan for two main reasons (i) for the synthesis of niacin and (ii) to raise serotonin levels, which is essential for the regulation of sleep, appetite and mood. The vast majority of proteins contain about 1 % of tryptophan and it is suggested that approximately 100 g of protein intake a day will be sufficient to ensure optimum levels of niacin in the body. The recommended dose of niacin is higher when there is an increase in physiological states such as pregnancy and lactation. Importantly, the Committee of Medical Aspects of Food Policy (COMA) in the UK stated that the Reference Nutrient Intake (RNI) for niacin was 17 mg/day and 13 mg/day. 

O Reilly, P. 0. Some clinical aspects of nicotinic acid therapy in hypercholesteremia. Canad. med. Ass. J. 78, 402 (1958). 

A large number of compounds related chemically to nicotinic acid have been synthesized and tested as both antagonists to the vitamin and also as replacements for the vitamin in mammalian nutrition. Hundley (1SS6) has reviewed certain aspects of this problem in animal nutrition and Knight (iS7) for bacteria. 

Albery and Hadgraft [16] have taken the trouble to validate aspects of the procedures and mathematics of RDC work, particularly the applicability of the Levich equation and rotating disk hydrodynamics. The work reported here confirms and extends their conclusions, by explicit discussion of concentration dependence, and use of a wider range of substances than carboxylic acids and nicotinate esters. This contrasts with results from... 

Casida JE, Tomozawa M (2008) Insecticide Interaction with y-Aminobutyric Acid and Nicotinic Receptors Predictive Aspects of Stractural Models. J Pestic Sci 33 4 Chen LG, Durkin KA, Casida JE (2006) Stractural Model for y-Aminobutyric Acid Receptor Noncompetitive Antagonist Binding Widely Diverse Structures Fit the Same Site. Proc Nat Acad Sci USA 103 5185... 

CIC The basic acid taste results from high levels of oxalic and succinic acid. (Z)-3-hexenol and (E)-2-hexenal contribute to the unripe, green aspect and ethyl benzoate with methyl-2-hydroxybenzoate are the typical medicinal notes. Quinoline and ethyl nicotinate add the earthy background. 

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