Pantothenic acid occurence

Figure 1 shows the structure of pantothenic acid ((R)-(+)-N-(2,4-dihydroxy-3,3 -dimethyl-1 -oxobuty 1-13-alanine). Only D(+)-pantothenic acid occurs naturally and is biologically active. The alcohol (R)-pantothenol (= (D)-panthenol) shows biological activity as well. 

Pantothenic acid occurs in foods both in the free form and bonded to coenzyme (CoA) or acyl carrier protein (ACP) therefore hydrolysis is needed to extract it totally. Since it is degraded by acid and alkaline hydrolysis, only an enzymatic digestion can be applied. Enzyme hydrolysis with papain, diastase, clarase, takadiastase, intestinal phosphatase, pigeon liver pantetheinase, or combination of them has been used. 

Endogenous pantothenic acid occurs in food primarily in the bound form as a component of coenzyme A (CoA or CoASH), acyl-coenzyme A, and acyl carrier protein (ACP) (185,186). These are the principal vitamers in foods free pantothenic acid (Fig. 9) is much less common. Only the D( + ) or (R) enantiomer of pantothenic acid occurs naturally. 

Pantothenic acid occurs in all living cells and tissues and is, therefore, found in most food products. Good dietary sources include meats, liver, kidney, fruits, vegetables, milk, egg yolk, yeast, whole cereal grains, and nuts (Table 9-26). In animal products, most of the pantothenic acid is present in the bound... 

FIGURE 431 Coen -yfne A- The vitamin, pantothenic acid, occurs as part of the structure of coenzyme A,... 

Pantothenic acid occurs in nature only as the d-(+)- or the (7 )-enantiomer the l(—)- or (5)-form has no vitamin activity (Sarett and Barboriak 1963). The CAS number of l(—)-acid is 37138-77-5 and the lUPAC name is 3-[[(25)-2,4-dihy-droxy-3,3-dimethyl-butanoyl]amino]propanoic acid. 

Pantothenic acid occurs in nature only as the D-(-l-)-enantiomer. The l(—)-form does not have vitamin activity. 

Synthetic pantothenic acid is a racemic compound comprising d(- -) and l(—) forms. Pantothenic acid occurs naturally as the d(+) isomer and is biologically active. l(—)-Pantothenic acid is biologically inactive and the racemic compound, oL-pantothenic acid, has half the biologieal activity of D(+)-pantothenic acid. However, large excess administration of l(—)-pantothenic acid to young rats causes growth retardation. 

Pantothenic acid (Formula 6.14) is the building unit of coenzyme A (CoA), the main carrier of acetyl and other acyl groups in cell metabolism. Acyl groups are linked to CoA by a thioester bond. Pantothenic acid occurs in free form in blood plasma, while in organs it is present as CoA. The highest concentrations are in liver, adrenal glands, heart and kidney. 

About 85% of dietary pantothenic acid occurs as CoA or phosphopantetheine. In the intestinal lumen these are hydrolysed to pantetheine intestinal mucosal cells have a high pantetheinase activity and rapidly hydrolyse pantetheine to pantothenic acid. The intestinal absorption of pantothenic acid is by diffusion and occurs at a constant rate throughout the length of the small intestine intestinal bacterial synthesis may contribute to pantothenic acid nutrition. 

Deficiencies of pantothenic acid occur in farm animals (especially chickens and swine), fed natural rations. As a result, pantothenic acid is commonly added to commercial poultry and swine rations. 

In terms of amino acids bacterial protein is similar to fish protein. The yeast s protein is almost identical to soya protein fungal protein is lower than yeast protein. In addition, SCP is deficient in amino acids with a sulphur bridge, such as cystine, cysteine and methionine. SCP as a food may require supplements of cysteine and methionine whereas they have high levels of lysine vitamins and other amino acids. The vitamins of microorganisms are primarily of the B type. Vitamin B12 occurs mostly hi bacteria, whereas algae are usually rich in vitamin A. The most common vitamins in SCP are thiamine, riboflavin, niacin, pyridoxine, pantothenic acid, choline, folic acid, inositol, biotin, B12 and P-aminobenzoic acid. Table 14.4 shows the essential amino acid analysis of SCP compared with several sources of protein. 

Pantothenic acid is a metabolic precursor to coenzyme A, which is involved in a very large number of reactions that occur in all phases of metabolism. 

Pantothenic acid (Figure 19.19) is known also as vitamin Bj. It is A-(2,4-dihydroxy-3,3-dimethyl-l-oxobutyl)- 3-alanine. It occurs in nature only in the o-form. Free pantothenic acid and its sodium salt are chemically unstable, and therefore the usual pharmacological preparation is the calcium salt (calcium pantothenate). The latter is stable in neutral solutions but it is destroyed by heat and acid solution. 

UV absorption occurs only below 220nm, thereby it is affected by the interference from mobile phase and from artifacts in complex foods. A multiwavelength UV detection has been experimented successfully for unambiguous evaluation of pantothenic acid [609]. However, UV detection presents a low sensitivity, compared to other techniques, like FLD or MS. FLD is applied by using a postcolumn derivatization. Pantothenic acid is converted to 3-alanine by hot alkaline hydrolysis and a reaction with OPA [610]. Also MS is successfully applied to increase the sensitivity of pantothenic acid analysis. 

Pantothenic acid (8.48), a hydroxyamide, occurs mainly in liver, yeast, vegetables, and milk, but also in just about every other food source, as its name implies [pantos (Greek) = everywhere]. It is part of coenzyme A, the acyl-transporting enzyme of the Krebs cycle and lipid syntheses, as well as a constituent of the acyl carrier protein in the fatty-acid synthase enzyme complex. 

Vitamins are required for satisfactory development or function of most yeasts. Wickerham (177) devised a complete yeast medium which included eight vitamins biotin, pantothenic acid, inositol, niacin, p-aminobenzoic acid, pyridoxine, thiamine, and riboflavin. The concentrations of these growth factors varied widely with inositol in the greatest concentration and biotin in trace amounts. Many of these vitamins are considered major growth factors for yeast multiplication and development, as noted in several studies and reviews (178, 179, 180, 181, 182). Generally, the benefit of adding vitamins to musts and wines has not been established as a normal winery practice. This lack of response is because vitamins occur naturally in sufficient quantities in grapes and are produced by yeasts themselves (3). 

An additional series of reactions,350 which are shown in Eq. 24-38, leads to pantoic acid, pantetheine, coenzyme A, and related cofactors.350a i The initial reactions of the sequence do not occur in the animal body, explaining our need for pantothenic acid as a vitamin. 

The most abundant amino acids are those that are protein constituents and these are always a-amino acids. However, there are many other amino acids that occur naturally in living systems that are not constituents of proteins, and are not a-amino acids. Many of these are rare, but others are common and play important roles in cellular metabolism. For example, 3-aminopropanoic acid is a precursor in the biosynthesis of the vitamin, pantothenic acid,2... 

Apart from pantothenic acid, which has been attributed loads of helpful effects in skin care and occurs quite frequently as dexpanthenol in cosmetic and medical formulations, the other vitamins of the B-complex are so far not known for specific positive results on skin, neither topically nor systemically. Nevertheless, some ideas for applications might eventually lead to new treatment options. 

It is apparent that at this stage of development definitive conclusions are premature, and that this aspect of amino acid and lipide metabolism will be pursued vigorously in the near future. It is of considerable interest to us that biotin and pantothenic acid deficiencies affect amino acid transport in L. arabinosus, since both vitamins are known to play a prominent role in lipide biosynthesis. We are currently reexamining the turnover of lipide fractions in nutritionally normal and vitamin-deficient cell types to determine whether there is some relation between this aspect of metabolism and amino acid transport. In any case, the nature of the catalytic steps involved in amino acid transport is still unknown to us. They probably occur in the peripheral cell membrane, but even this elementary and widely accepted belief will require additional study before it can be accepted beyond doubt as an established fact. 

Some of the less common d enantiomers of amino acids are also found in nature. For example, D-glutamic acid is found in the cell walls of many bacteria, and D-serine is found in earthworms. Some naturally occurring amino acids are not a-amino acids y-Aminobutyric acid (GABA) is one of the neurotransmitters in the brain, and jS-alanine is a constituent of the vitamin pantothenic acid. 

A large number of amino acids involved in metabolism are not found in proteins e.g., /3-alanine, OOC—CH2—CH2—NH, is an intermediate in the synthesis of the B vitamin pantothenic acid, but it is not found in proteins. Although most naturally occurring amino acids are of the t. configuration, some o-amino acids arc found in certain antibiotics and in the cell walls of some bacteria. 

Calcium Pantothenate occurs as a slightly hygroscopic, white powder. It is the calcium salt of the dextrorotatory isomer of pantothenic acid. It is stable in air. One gram dissolves in about 3 mL of water. It is soluble in glycerin, but is practically insoluble in alcohol, in chloroform, and in ether. 

DL-Panthenol occurs as a white to creamy white, crystalline powder. It is a racemic mixture of the dextrorotatory (active) and levorotatory (inactive) isomers of panthenol, the alcohol analogue of pantothenic acid. It is freely soluble in water, in alcohol, and in propylene glycol. It is soluble in chloroform and in ether, and is slightly soluble in glycerin. Its solutions are neutral or alkaline to litmus. 

The only naturally occurring vitamer of pantothenic acid is the o-isomer (as shown in Figure 12.1). It is the peptide of pantoic acid and /3-alanine. 

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