Pantothenic acid synthetic form

Very little is known about the pantothenic acid needs of human beings even though it has been about 14 years since this vitamin in synthetic form became available. The backwardness is due in part to the fact that pantothenic acid deficiency often does not give rise to... 

The synthetic form is the alcohol, panthenol, which can be oxidized in vivo to pantothenic acid. It is included in the list of substances that may be added in foods and in food supplements [403], Pantothenic acid is part of the coenzyme A (CoA) molecule therefore it is involved in acylation reactions, such as in fatty acid and carbohydrate metabolism. 

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. 

Thiamine, biotin, pantothenic acid, riboflavin and vitamin B12 are involved in propionic acid fermentation. Biotin forms the prosthetic group of methyl-malonyl-CoA transcarboxylase pantothenate is a constituent of CoA thiamine is not the coenzyme (co-carboxylase) of the enzyme carboxylase like in other organisms, for acetaldehyde has not been detected in propionibacteria (although traces were recently found), but it may function as a component of dehydrogenases in oxidative phosphorylation of a-keto acids. Riboflavin is a constituent of FAD and FMN. Propionibacteria can synthesize vitamins B2 and B in considerable amounts (see below), but the other three vitamins must be supplied. Some strains can grow in synthetic media without thiamine (Silverman and Workman, 1939 Delwiche, 1949), in some other strains thiamine can be replaced by / -aminobenzoic acid. 

Glycinamide ribonucleotide kinosynthetase is the name applied to the partially purified enzyme that forms GAR from glycine, ATP, and PRA (99). It is of interest that the sjmthesis of the amide bond of GAR resulted in the formation of ADP and P after interaction of ATP with the substrates. This process is similar to the events in glutamine (100-103) and glutathione (104) S3mthesis. Other amide bond syntheses such as amino acid activation (105) and pantothenic acid biof thesis (106) are characterized by the formation of AMP and PP from ATP during the synthetic event. 

---