4′,4′′-Diphosphopantethine

4′,4′′-Diphosphopantethine is a dinucleotide derivative of pantetheine that functions as an important intermediate in the biosynthesis of coenzyme A. It contains two phosphopantetheine moieties connected via a phosphate linkage, which facilitates the transfer of acyl groups in various metabolic processes. This molecule plays a key role in enzymatic reactions involving acyl carrier proteins, supporting the synthesis of fatty acids, polyketides, and other biologically relevant compounds (Jackowski & Rock, 1984; Cronan, 2001).