Memory effect of diethylamine mobile phase additive on chiral separations on polysaccharide stationary phases

Chirality ◽  
2004 ◽  
Vol 16 (8) ◽  
pp. 493-498 ◽  
Author(s):  
Rodger W. Stringham ◽  
Kenneth G. Lynam ◽  
Barbara S. Lord
Keyword(s):  
Memory Effect ◽  
Mobile Phase ◽  
Stationary Phases ◽  
Chiral Separations ◽  
Mobile Phase Additive

Synthesis and Chiral Separation of Some 4-thioflavones

2021 ◽  
Author(s):  
Mohammed El Amin Zaid ◽  
Nasser Belboukhari ◽  
Khaled Sekkoum ◽  
Bousmaha Ibtissam ◽  
Hassan Y Aboul Enein
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Wittig Reaction ◽  
Stationary Phases ◽  
Enantiomeric Separation ◽  
Chiral Separations ◽  
Chiral Discrimination ◽  
Set Up

Abstract A thionation reaction was performed on some chiral flavanones using Lawesson’s reagent (LR) and leads to the formation of new chiral thiocarbonyl flavanes. LR in this thionation reaction with Hesperetin and Naringenin gives new flavan-4-thiones with yields ranged between 41 and 52%. Based on the Wittig reaction principle, LR is currently the most widely used reagent for this type of reaction. Enantiomeric separation by high-performance liquid chromatography methods was then set-up using three different polysaccharide-based chiral stationary phases (CSPs). Chiral separations were successfully accomplished with high resolution (1.22 ≤ Rs ≤ 5.23). The chiral discrimination mechanism(s) between the analytes under study, mobile phase, and the CSPs were discussed.

scholarly journals Recent Advances in Chiral Analysis of Proteins and Peptides

Separations ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 112
Author(s):  
Marine Morvan ◽  
Ivan Mikšík
Keyword(s):  
Amino Acids ◽  
Stationary Phases ◽  
Enzymatic Digestion ◽  
Chiral Separations ◽  
Biological Compounds ◽  
Health And Disease ◽  
Electrophoretic Techniques ◽  
A Site ◽  
Future Work ◽  
Proteins And Peptides

Like many biological compounds, proteins are found primarily in their homochiral form. However, homochirality is not guaranteed throughout life. Determining their chiral proteinogenic sequence is a complex analytical challenge. This is because certain D-amino acids contained in proteins play a role in human health and disease. This is the case, for example, with D-Asp in elastin, β-amyloid and α-crystallin which, respectively, have an action on arteriosclerosis, Alzheimer's disease and cataracts. Sequence-dependent and sequence-independent are the two strategies for detecting the presence and position of D-amino acids in proteins. These methods rely on enzymatic digestion by a site-specific enzyme and acid hydrolysis in a deuterium or tritium environment to limit the natural racemization of amino acids. In this review, chromatographic and electrophoretic techniques, such as LC, SFC, GC and CE, will be recently developed (2018–2020) for the enantioseparation of amino acids and peptides. For future work, the discovery and development of new chiral stationary phases and derivatization reagents could increase the resolution of chiral separations.

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