Synthesis and preliminary pharmacological evaluation of pidotimod, its enantiomer, diastereomers and carboxamido derivatives

A new compound with a peptide-like structure, (R)-3-[(S)-(5-oxo-2-pyrrolidinyl)carbonyl]-thiazolidine-4-carboxylic acid, its enantiomer, diastereomers and carboxamido derivatives were synthesized and tested for immunostimulant activity. Synthesis, preliminary, pharmacological data and structure-activity relationships are reported. (R)-3-[(S)-(5-Oxo-2-pyrrolidinyl)carbonyl]-thiazolidine-4-carboxylic acid (Ib, Pidotimod, PGT/1A, CAS 121808-62-6) was selected for further research.

Analytical and chemical profile of pidotimod

Pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl)carbonyl]-thiazolidine- 4-carboxylic acid, PGT/1A, CAS 121808-62-6) is a new synthetic immunostimulant, which has proved to possess a high activity. This paper describes its physico-chemical properties, structural identification including polymorphism, detection of impurities, determination of related compounds, separation, quantification and purity assay using high-performance liquid chromatography (HPLC).