Stereomeric resolution and modeling of dl-alanine-dl-phenyl alanine dipeptide on an AmyCoat-RP column
Stereomeric resolution and docking studies of four stereomers of DL-alanine-DL-phenyl alanine dipeptide were performed with an AmyCoat-RP column. The eluent used was methanol : ammonium acetate (10 mM) : formic acid (70 : 30 : 0.05, v/v) with 0.8 mL min−1 flow rate, 275 nm detection and 27 ± 2 °C temperature. The values of retention factors for LL-, DD-, DL- and LD-stereomers were 1.36, 2.21, 8.63 and 11.3. The values of separation factors were 1.63, 3.91 and 1.31. The values of resolution factors were 1.70, 6.43 and 2.14, respectively. The detection and quantitation limits were 0.62–1.43 and 3.10–10.0 ng. The docking studies have proven the order of elution and the stereomeric mechanism. The different forces responsible for stereomeric resolution were hydrogen bonding, hydrophobic interactions, π–π forces, van der Waals attractions, and steric effects. The described stereomeric resolution of the reported racemic dipeptide is highly useful. It may be used to access the quantities of various stereomeric compounds in any unknown matrix.