Enantiomeric resolution and modeling of DL‐alanine‐DL‐tryptophan dipeptide on amylose stationary phase

Abstract

The enantiomeric resolution of DL-alanine-DL-tryptophan dipeptide is described on amylose stationary phase. The eluent used was CH OH─CH COONH (10mM)─CH CN (50: 40, 10) at 0.8-mL/min flow, 230-nm detection, 25-minute run time, and 25°C ± 1°C temperature. The chiral phase was amylose [AmyCoat RP (15 cm × 0.46 cm × 5 micron)]. The magnitudes of the retention factors (k) were 2.71, 3.52, 5.11, and 7.75. The magnitudes of separation factor (α) were 1.19, 1.57, and 1.51 while the resolution factors (Rs) were 3.25, 14.84, and 15.76. The limits of detection and quantitation were of 2.5 to 5.4 and 12.8 to 27.5 μg/mL. The enantiomeric resolution is controlled by hydrogen, hydrophobic, π-π, steric, etc interactions. The elution order of the enantiomer was supported by the modeling data. The described method is fast, reproducible, precise, and selective, which can be used successfully for evaluating the enantiomers of the reported dipeptide.

Enantioseparation and molecular modeling study of chiral amines as three naphthaldimine derivatives using amylose or cellulose trisphenylcarbamate chiral stationary phases

“…Based on the molecular docking simulations results, the elution orders of the three analytes of leucinol as naphthaldimine derivatives on the cellulose tris(3,5‐dimethylphenylcarbamate) chiral selector can be predicted and rationalized 38 . First, in our experiment, all three (S)‐leucinol derivatives were selectively retained on the CSPs derived from cellulose tris(3,5‐dimethylphenylcarbamate).…”

“…Based on the molecular docking simulations results, the elution orders of the three analytes of leucinol as naphthaldimine derivatives on the cellulose tris(3,5-dimethylphenylcarbamate) chiral selector can be predicted and rationalized. 38 the theoretical molecular docking studies in Table 7, higher binding energy of all three (S)-leucinol derivatives resulted in stronger retention of the enantiomer in the chiral selector. Thus, the predicted order of elution of analytes by molecular docking simulation was also (R)-leucinol > (S)-leucinol for the three analytes studied, which is further supported by the identical order of elution of the enantiomers, as shown by comparative data of Table 8.…”

Chiral recognition and discrimination studies of tyrosine enantiomers on (−)‐18‐crown‐6‐tetracarboxylic acid as a chiral selector by nuclear magnetic resonance spectroscopy and docking simulations

“…In docking simulation, the nature of complexation and the enantioselectivity (α) of a pair of enantiomers can be predicted and rationalized by considering the binding affinities and their differences (ΔE and ΔΔE, kcal/mol). 40 Table 4 shows the comparative experimental (HPLC and NMR) and theoretical simulation data of protonated Tyr with (À)-18-C-6-TA. In both NMR and HPLC data presented using (À)-18-C-6-TA, L-Tyr shows stronger complexation with (À)-18-C-6-TA than D-Tyr.…”

Synthesis of Tripeptide Derivatives with Three Stereogenic Centers and Chiral Recognition Probed by Tetraaza Macrocyclic Chiral Solvating Agents Derived from d-Phenylalanine and (1S,2S)-(+)-1,2-Diaminocyclohexane via 1H NMR Spectroscopy

“…So far, reported research relying on 1 H NMR spectroscopy largely implicates enantiomeric discrimination of chiral analytes with only one stereogenic center. , In contrast, studies on enantiomeric discrimination of chiral analytes possessing two or more stereogenic centers have been rarely reported . Nevertheless, these chiral analytes often exist in natural products, biological systems, chiral drugs, and products of catalytic asymmetric synthesis . For example, it is well established that several oligopeptides or their derivatives, play a crucial role in the treatment of human diseases as clinical drugs or special dietary supplements, as exemplified by thyrotropin-releasing hormone (TRH) or its analogues, and aspartame, which have been used clinically for the treatment of spinocerebellar degeneration and disturbance of consciousness in humans, as well as in special dietary supplements, respectively.…”