Pellagra

Pellagra is a disease caused by a deficiency of niacm (C6FI5NO2) in the diet Niacin can be synthesized in the laboratory by the side chain oxidation of 3 methylpyndine with chromic acid or potassium permanganate Suggest a reasonable structure for niacin... 

Our word vitamin was coined m 1912 m the belief that the substances present m the diet that prevented scurvy pellagra beriberi rickets and other diseases were vital amines In many cases that belief was confirmed certain vitamins did prove to be amines In many other cases however vitamins were not amines Nevertheless the name vitamin entered our language and stands as a reminder that early chemists recognized the crucial place occupied by amines m biological processes... 

Pella r, Nia.cin Deficiency. It was 220 years after the first description of pellagra that nicotinic acid was discovered to be the cure for black tongue in dogs (14), a condition suggested by a veterinarian in North Carolina to be similar to human pellagra (15). 

In this period, the empirical healing of certain diseases by foods was estabUshed. Examples (3) were the treatment of night blindness (vitamin A deficiency) with hver ia many cultures over centuries, of beriberi (vitamin deficiency) by use of unpoHshed rice by the Japanese navy, of scurvy (vitamin C deficiency) by citms fmits ia the British navy or piae needle extracts by North American natives, and pellagra (niacia deficiency) by a dietary shift away from corn-based foods ia many countries. Other, nondietary empirical treatments iavolved, eg, exposure of children ia northern latitudes to sunlight to cute tickets (vitamin D deficiency) (4). 

In 1913, Goldberger demonstrated that pellagra was due to a dietary deficiency. Pellagra had been eadier described by Thiery, who had coined the term mal de la rosa for this disease. Several decades later, Elvehjem and co-workers isolated nicotinamide from a Hver extract and identified it as a peUagra-preventing factor (1). 

NADP can be converted to nicotinic acid adenine dinucleotide phosphate (NAADP), which has distinct functions in the regulation of intracellular calcium stores. The studies of these new roles of NAD(P) in metabolism are in their early stages, but they might soon help to better understand and explain the symptoms of niacin deficiency ( pellagra) [1]. 

Niacin is recommended to alleviate pellagra, a disease caused by a deficiency of this vitamin. 

PEG. See polyethylene glycol esters PEG-5 cocamide, 136, 201 PEG-6 methyl ether, 209 PEG-n. See polyethylene glycol pellagra, 188 pentane, 226-227... 

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. 

Niacin Nicotinic acid, nicotinamide Coenzyme in oxidation and reduction reactions, functional part of NAD and NADP Pellagra—photosensitive dermatitis, depressive psychosis... 

Niacin was discovered as a nutrient during studies of pellagra. It is not strictly a vitamin since it can be synthesized in the body from the essential amino acid tryptophan. Two compounds, nicotinic acid and nicotinamide, have the biologic activity of niacin its metabolic function is as the nicotinamide ring of the coenzymes NAD and NADP in oxidation-reduction reactions (Figure 45-11). About 60 mg of tryptophan is equivalent to 1 mg of dietary niacin. The niacin content of foods is expressed as mg niacin equivalents = mg preformed niacin + 1/60 X mg tryptophan. Because most of the niacin in cereals is biologically unavailable, this is discounted. 

Pellagra is characterized by a photosensitive dermatitis. As the condition progresses, there is dementia, possibly... 

Pellagra Can Occur as a Result of Disease Despite an Adequate Intake of Tryptophan Niacin... 

A number of genetic diseases that result in defects of tryptophan metabolism are associated with the development of pellagra despite an apparently adequate intake of both tryptophan and niacin. Hartnup disease is a rare genetic condition in which there is a defect of the membrane transport mechanism for tryptophan, resulting in large losses due to intestinal malabsorption and failure of the renal resorption mechanism. In carcinoid syndrome there is metastasis of a primary liver tumor of enterochromaffin cells which synthesize 5-hydroxy-tryptamine. Overproduction of 5-hydroxytryptamine may account for as much as 60% of the body s tryptophan metabolism, causing pellagra because of the diversion away from NAD synthesis. 

Nicotinamide 10 Nicotinamide Treatment of pellagra Hydrolysis Rhodococcus rhodochrous Immobilized cells [7]... 

June, 1912 Casimir Funk, a Polish biochemist working in London, England, wrote a review article in which he elaborated on the fact that diseases such as scurvy, beri-beri, rickets and pellagra had long been known to be associated with the dietary. Funk said that these diseases could be prevented or cured by adding certain organic substances to the diet, substances he called vitamines. 0 )... 

The last of the B vitamins to be identified in the water-soluble vitamin complex from milk was pyridoxine, vitamin B6 (Birch and Gyorgy, 1936). This was needed to prevent a type of dermatitis in rats which was different from pellagra or acrodynia and could be accompanied by convulsions. Much of the early work on the mode of action of this vitamin came from experiments on microbial metabolism (Chapter 6). 

In 1917, comparative studies were carried out in Georgia (USA) to evaluate the effects of diets on children with pellagra. Children were selected from orphanages. This practice would not be allowed today, as institutionalized children, who could not defend their rights, were taken advantage of. 

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