Mupirocin calcium EP impurity E sodium salt

Mupirocin calcium EP impurity E sodium salt is a sodium-substituted derivative of the calcium complex of Mupirocin impurity E, characterized by a cyclic beta-lactone core fused to a decalin ring system. The molecule features multiple hydroxyl groups, ester linkages, and a sodium counterion coordinating to the carboxylate moiety. Structurally, it represents a degradation byproduct arising from hydrolytic cleavage of the parent Mupirocin calcium complex, retaining the core tricyclic scaffold but lacking the terminal isoleucine residue. This compound serves as a critical HPLC reference standard for quantifying impurity E in Mupirocin-based pharmaceutical formulations.