Pantothenic acid vitamers

Free pantothenic acid and its sodium salt are chemically unstable, and therefore the usual pharmacological preparation is the calcium salt (calcium 

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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. 

The availability of commercial bench-top mass spectrometry detectors for HPLC is facilitating the development of HPLC-MS methods for many analytes. This is more common in pharmaceutical than food applications. As is generally the case, mass spectrometry is first being applied to standard solutions and relatively simple samples before being applied to more complex food matrices. A standard mixture of ten vitamers, AA, DHAA, PN, PL, PM, thiamine, nicotinic acid, nicotinamide, pantothenic acid and biotin, were recently determined by HPLC-particle beam... 

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. 

Tahiliani AG, Beinlich CJ. Pantothenic acid in health and disease. Vitam. Horm. 1991 46 165-228. 

RaUi EP, Dumm ME. Relation of pantothenic acid to adrenal cortical function. Vitam Horm 1953 11 133-58. 

The method of choice for the determination of most vitamins is HPLC due to its high separation capability, its mild analytical conditions, and the possibility to use various specifically adapted detection methods, e.g., LTV, fluorescence, or MS detection. All fat-soluble vitamins and most water-soluble vitamins have chromophores suitable for UV detection. Separation of vitamers and stereoisomers can be achieved. If a higher sensitivity is required HPLC with fluorescence detection can be used, either directly (e.g., vitamins A and E) or after derivatization (e.g., thiamine). A further improvement in sensitivity and specificity has been achieved by introducing HPLC with mass spectrometric detection in vitamin analysis. Due to the structural information retrievable, e.g., molecular mass, fragmentation pattern, this is the method of choice for analysis of samples with complex mixtures or low vitamin concentrations. Examples for the use of HPLC-MS in vitamin analysis include the determination of 25-hydroxy-D3 and pantothenic acid. However, one drawback of mass spectrometry is the need for an isotopically labeled reference compound for reliable quantification. Due to the structural complexity of many vitamins, these reference compounds are often expensive and difficult to synthesize. An interesting unique application is the determination of vitamin B12 by HPLC-IPC-MS, which is possible due to its cobalt content. 

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