The vitamin B complex

The symptoms of vitamin K deficiency in chicks are anaemia and a delayed clotting time of the blood birds are easily injured and may bleed to death. It is doubtful whether, in birds, microbially synthesised vitamin K is available by direct absorption from the digestive tract, because the site of its formation is too distal to permit absorption of adequate amounts except by ingestion of faecal material (coprophagy). 

The vitamins included under this heading are all soluble in water and most of them are components of coenzymes (see Table 5.3). Although the mechanism of action in this role is known, the connection between the observed deficiency symptoms and the failure of the metabolic pathways is not always clear. 

Unlike the fat-soluble vitamins, members of the vitamin B complex, with the exception of cyanocobalamin, are not stored in the tissues in appreciable amounts and a 

Vitamin Coenzyme or prosthetic group Enzyme or other function 

Riboflavin Flavin adenine dinucleotide (FAD) Hydrogen carrier 

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Folic acid is a member of the vitamin B complex found in green plants, fresh fruit, yeast, and liver. Folic acid takes its name from folium, Latin for leaf. Pterin compounds are named from the Greek word for wing because these substances were first identified in insect wings. Two pterins are familiar to any child who has seen (and chased) the common yellow sulfur butterfly and its white counterpart, the cabbage butterfly. Xanthopterin and leu-... 

The following substances have been added to culture media to increase the yields of dextran raw beet sugar or molasses,80 commercial maple sirup,1 yeast extract,81 magnesium and ammonium sulfates,82 tomato juice,8,81 calcium carbonate,3 and a water extract of waste sugarrefining charcoal (probably containing materials related to the vitamin B complex).88... 

B26. Barton-Wright, E. C., Microbiological Assay of the Vitamin B-Complex and Amino Acids. Pitman, London, 1952. 

Historically choline, inositol and carnitine have been considered to be part of the vitamin B complex. However, for the general population there has been no demonstration of a dietary need for these agents and also for none of them has there been a therapeutic role established. Vitamins of the B family are found in many food ingredients like in yeast, in meat, in dairy products and also in eggs and grain cereals and separate vitamin B deficiencies are unlikely to occur. Excessive intake of these vitamins is eliminated in the urine because of the fact that they are water-soluble. 

Vitamin Bg (8.47, pyridoxine) is a pyridine-alcohol, but its biologically active forms are pyridoxal 5-phosphate and the corresponding pyridoxamine. Like all the members of the vitamin B complex, it occurs in yeast, bran, wheat germ, and liver. It is a coenzyme of... 

Studies on the vitamin B complex Further indications for the presence of a third factor. Ibid., 8, 169, (1935). With R. B. Hubbell. 

D-(-)-Pantoyl lactone 1s a key intermediate for the synthesis of pantothenic acid which is a member of the vitamin B-complex and is an important constituent of Coenzyme A. Although D-(-)-pantoyl lactone has been obtained by classical optical resolution using quinine, ephedrine, and other chiral amines, catalytic asymmetric synthesis appears to be more effective... 

Table 8.9 lists the water-soluble vitamins —ascorbic acid (vitamin C) and a series known as the vitamin B complex (Figure 8.32). Ascorbate, the ionized form of ascorbic acid, serves as a reducing agent (an antioxidant), as will be discussed shortly. The vitamin B series comprises components of coenzymes. Note that, in all cases except vitamin C, the vitamin must be modified before it can serve its function. 

Vitamins are small biomolecules that are needed in small amounts in the diets of higher animals. The water-soluble vitamins are vitamin C (ascorbate, an antioxidant) and the vitamin B complex (components of coenzymes). Ascorbate is required for the hydroxylation of proline residues in collagen, a key protein of connective tissue. The fat-soluble vitamins are vitamin A (a precursor of retinal), D (a regulator of calcium and phosphorus metabolism), E (an antioxidant in membranes), and K (a participant in the carboxylation of glutamate). 

A number of widely differing substances are now, for convenience, classed the vitamin B complex. Those used for pharmacotherapy include the following ... 

A vitamin B complex (vitamin Bj, vitamin B2, vitamin Bg, vitamin B12, and folic acid) was also separated into its components using TLC plates impregnated with different transition metal ions. CUSO4 at 0.4% impregnation in aU the employed solvent systems resulted in the simultaneous resolution of constituents of the vitamin B complex with appreciable differences in Rf values. 

Thioamides are useful synthons for the preparation of different types of nitrogen-sulfur heterocycles for instance, thiazoles (95) are synthesised by condensation of a thioamide with an a-chlorocarbonyl compound (96) (Scheme 53). Vitamin B1 (thiamine) (97a) (Figure 5) is a thiazole derivative and is a member of the vitamin B complex required for growth and the proper functioning of the nervous system. It is a cofactor in biological decarboxylation reactions and exists... 

CAS 62-49-7. (CH3)3N(OH)CH2CH2OH. Member of the vitamin B complex. Essential in the diet of rats, rabbits, chickens, and dogs. In humans it is required for lecithin formation and can replace methionine in the diet. There is no evidence of disease in humans caused by choline deficiency. It is a dietary factor important in furnishing free methyl groups for transmethylation has a lipotropic function. 

A member of the vitamin-B complex it is a component of coenzyme A and may be considered a (3-alanine derivative with a peptide linkage. It is involved in the release of energy from carbohydrate utilization and is necessary for synthesis and degradation of fatty acids, sterols, and steroid hormones it also functions in the formation of porphyrins. It occurs in all living cells and tissues. The natural product is dextrorotatory [d(+)] and is the only form having vitamin activity. 

Biotin is one of about a dozen water-soluble factors of the vitamin B complex and is a coenzyme for enzymes involved in carboxylation reactions. The carboxyl group of the valeric acid side chain of (-f )-biotin is covalently linked through an amide bond to the s-amino group of a lysyl residue of those enzymes. The antibacterial function of avidin by binding biotin and inhibiting all biotin-enzymes is plausi-... 

W3. Wills, L., Studies in pernicious anaemia of pregnancy tropical macrocytic anaemia as a deficiency disease with special reference to the vitamin B complex. Indian J. Med. Res. 21, 669-681 (1934). 

Folic acid 14 consists of 6-methylpterine, p-aminobenzoic acid and (5)-glutamic acid residues. It belongs to the vitamin B complexes group and has been isolated from spinach leaves. Folic acid is a growth hormone and effective in the treatment of certain types of anaemia. It is important for the metabolism of amino acids, proteins, purines and pyrimidines. Folic acid forms orange, water-insoluble crystals, mp 250°C (dec). Its synthesis is carried out by condensation of 6-hydroxy-2,4,5-triaminopyrimidine, 1,1,3-trichloroacetone and A -(4-aminobenzoyl)-( S)-glutamic acid at pH 4-5 and in the presence of NaHSOs ... 

Precautions A member of the vitamin B complex. FDA approves use within limitations. Recommended dietary allowance is 180 meg a day. 

Biological function P. is a biosynthetic precursor of coenzyme A. P. is present in coenzyme A bound to cys-teamine as pantetheine, C, H22N2O4S, Mr 278.37, [a] +12.9° (HjO). P. is considered to bdong to the vitamin B complex deficiency symptoms in chickens are loss of feathers. 

Deficiency of pantothenic acid causes depigmentation while administration of folic acid increases hepatic storage of pantothenic acid as the Vitamin B-complex acts synergistically with folic acid in normal pigmentation (269). Ascorbic acid maintains optimum sulfhydryl levels in the body and keeps melanin in reduced form (262). Any change in the... 

Other fractions of the vitamin B complex have also been tested for their effect on the survival of young adrenalectomized rats, and it was found that biotin was as effective as pantothenate (Ralli and Dumm, 1952). This is interesting in view of the previous discussion of the interrelation of biotin and pantothenic acid (see Section V.b). In this same series of experiments it was observed that large doses of pyridoxine were toxic to adrenalectomized rats when given after a period of pantothenate deficiency. Thiamine and riboflavin had no influence on survival, but folic acid and vitamin Bu resulted in a moderate improvement. These observations emphasize the interaction of vitamins under various nutritional situations in relation to hormone action. 

Folic acid is part of the vitamin B complex, and its electrochemical and biological reduction schemes have been reported by Dryhurst. Its fully reduced form, tetrahydrofolic acid, is important because it acts as a carrier for a formate unit. Thus, formyl-N -tetrahydrofolic acid is involved in the biosynthesis of nucleic acid, primary constituents of living cells. Alternating current adsorptive stripping voltammetry has been applied to the determination of (I) in human seru. ... 

Greenbaum J (1979) Vitamin A sensitivity. Ann Allergy 43 93-99 Greengard P (1970) Water soluble vitamins. I. The vitamin B complex. In The pharmacological basis of therapeutics, 4th edn. Colher Macmillan, London Toronto Groff IP, Blakley RL (1978) Rescue of human lymphoid cells from the effects of methotrexate in vitro. Cancer Res 38 3847-3853... 

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