Preparation and Enantiomeric Separation of L-Pro-L-Phe-L-Val-L-Leu Peptide Stationary Phases

This study presents the development of three new chiral stationary phases (CSP). Three new peptides CSPs with a main chain of L-proline (L-Pro), L-phenylalanine (L-Phe), L-valine (L-Val) and L-leucine (L-Leu) and different terminals of L-citrulline (L-Cit), L-lysine (L-Lys) and L-tryptophan (L-Typ) immobilized on 3-aminopropyltrimethoxysilane modified silica gel (APS) were prepared, furthermore, successful analyses and characterizations were conducted using Fourier transform infrared spectra, elemental analysis, and thermogravimetric analysis. After this, the enantioselective performance of the three L-Pro-L-Phe-L-Val-L-Leu peptide stationary phases columns were evaluated. The evaluation used 9 racemic compounds under normal-phase high performance liquid chromatography mode. Optimized enantiomeric separation conditions were established. Under these conditions, the resolutions of flurbiprofen, naproxen, benzoin, 1,1'-bi-2-naphthol and ketoprofen on the CSP-1 column were 1.61, 2.0, 0.62, 0.52, and 1.20, respectively. In addition, the reproducibility of the CSP-1 column was also investigated. The results of the investigation illustrated that the stationary phases have good reproducibility (RSD = 0.12%, n = 5).