Pitavastatin 3S,5S- isomer

Pitavastatin 3S,5S-isomer is a stereoisomeric impurity derived from the parent drug Pitavastatin, characterized by the (3S,5S) configuration at the pyrroline ring's chiral centers. It retains the core structure of Pitavastatin, including a hydrogenated naphthalene moiety, a pyrroline ring with a lactone side chain, and a fluorinated phenyl group. The isomerization at positions 3 and 5 introduces distinct stereochemical interactions, reducing pharmacological activity compared to the (3R,5S) parent compound. This impurity arises during asymmetric synthesis or degradation pathways, necessitating its quantification in quality control. It serves as an HPLC reference standard for impurity profiling in Pitavastatin formulations.