title: Detection and quantitation of low levels of protected and unprotected (R)-amino acids in the synthesis of thymopentin, an immunoregulatory peptide.
abstract: Two chiral chromatographic procedures (HPLC and capillary GC) were developed to monitor the extent of epimerization of protected and unprotected amino acids used in a synthesis of thymopentin, an immunoregulatory peptide currently in clinical trials. The capillary GC method allowed the detection of the (R)-enantiomer in the presence of the (S)-enantiomer at levels of greater than or equal to 0.2%, while the HPLC method allowed similar detection at levels of greater than or equal to 0.1%.
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D010446:Peptide Fragments / Q000138:chemical synthesis*; D013237:Stereoisomerism; D016305:Thymopentin; D013946:Thymopoietins / Q000138:chemical synthesis*; D013951:Thymus Hormones / Q000138:chemical synthesis*
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D013946:Thymopoietins; D013951:Thymus Hormones; D016305:Thymopentin