Highly Sensitive Determination of Amino Acids by LC-MS under Neutral Conditions

Peptide drug leads possess unusual structural features that allow them to exert their unique biological activities and ideal physicochemical properties. In particular, these peptides often have D-amino acids, therefore the absolute configurations of component amino acids be elucidated during determination newly isolated peptide leads. Recently, we developed highly sensitive labeling reagents D/L-FDVDA D/L-FDLDA for in peptides. an LC-MS-based study peptides, enabled us detect infinitesimal amounts derived from mild degradative analysis samples. Herein, firstly report improved LC-MS protocols analyses acids. Second, two new were synthesized detection sensitivities evaluated. These studies increase our understanding basis reagents, should provide opportunities future on-demand modifications enhance hydrophobicity, stability, affinity applications specialized HPLC columns.