Description
Pantothenic acid (vitamin B5) is synthesised by most microorganisms and plants from pantoic acid.
The vitamin is an integral part of 4-phosphopantetheine, which is a component of coenzyme A (CoA). CoA plays a key role in the metabolism of numerous compounds, especially lipids and the ultimate catabolic disposition of carbohydrates and ketogenic amino acids. About 80% of the vitamin in animal tissues is in CoA form, and the rest exists mainly as phosphopantetheine and phosphopantothenate.
Another essential role of pantothenic acid is its participation in the 4-phosphopantetheine moiety of acyl carrier protein (ACP), where the phosphodiester-linked prosthetic group uses the sulfhydryl terminus to exchange with malonyl-CoA to form an ACP-S malonyl thioester, which can chain elongate during fatty acid biosynthesis.
