Cyralis™ Chiral HPLC Columns
Polysaccharide-based stationary phases providing complementary cellulose and amylose selectivity for chiral separations.
How Polysaccharide Selectors Separate Enantiomers
Polysaccharide stationary phases separate racemates by inducing subtle energetic differences between enantiomers and the selector as they flow through and interact with the stationary phase. Common polysaccharide selectors contain large phenyl groups that provide π-π interactions.
Most selectors also contain carbamate NH groups capable of hydrogen bonding, as well as a highly stereoregular cavity .formed by the stereochemistry of the polysaccharide itself. These interactions provide anchors for racemates passing through the stationary phase. Enantiomeric discrimination occurs based on how effectively each enantiomer interacts with the selector’s aromatic system, hydrogen-bonding sites, and geometric structure. It’s predicted that hydrogen bonding interaction is the most important.
π-π Interactions
Interactions between aromatic groups of the analyte and the large phenyl groups of the selector.
Hydrogen Bonding
Hydrogen-bonding interactions provided by the carbamate NH functionality.
Geometric Recognition
Differences in how each enantiomer fits within the highly stereoregular cavity of the polysaccharide selector.
Cellulose- and Amylose-Based Chiral Selectors
Cellulose and amylose selectors should not be considered universally better or worse than one another. Instead, they provide complementary selectivity and are suitable for different types of molecules.
Cyralis™ CM
Beta-blockers, such as pindolol and propranolol, and proton pump inhibitors, including various prazoles, resolve better on cellulose-based phases.
Cyralis™ AM
2-Arylpropionic acids, including various profen drugs, and many
azole-type compounds tend to resolve better on amylose-based phases.
Although it is difficult to predict which compounds will separate well on a specific selector, several broad patterns have been observed. Because chiral recognition strongly depends on the three-dimensional structure of the analyte, a compound that separates well on one selector may show limited or no separation on the other.
Complementary Chiral Selectivity
The chromatograms below demonstrate how the two stationary phases can provide different selectivity for the same racemate.
Example 1: Separation Achieved on Cyralis™ CM
Effective separation on Cyralis™ CM and limited or no separation on Cyralis™ AM.
Example 2: Separation Achieved on Cyralis™ AM
Effective separation on Cyralis™ AM and limited or no separation on Cyralis™ CM.
Two Complementary Stationary Phases
Cyralis™ СM
Cellulose tris(3,5-dimethylphenylcarbamate) coated onto silica
Cyralis™ CM is a chiral HPLC column from SIELC Technologies. It
consists of the polysaccharide selector cellulose tris(3,5-dimethylphenylcarbamate) coated onto silica.
Suitable for: chiral neutral compounds, acids, bases and chiral salts.
50, 100, 150 and 250 mm
Particle sizes:
3, 5 and 10 μm
Cyralis™ AM
Amylose tris(3,5-dimethylphenylcarbamate) coated onto silica
Cyralis™ AM is a chiral HPLC column from SIELC’s Cyralis™ family. It consists of the helical polysaccharide selector amylose tris(3,5-dimethylphenylcarbamate) coated onto silica.
Suitable for: chiral neutral compounds, acids, bases and chiral salts.
50, 100, 150 and 250 mm
Particle sizes:
3, 5 and 10 μm
Compatible Chromatographic Modes
Alkane/alcohol mixtures
Alcohol/acetonitrile mixtures
Reversed-phase conditions
High-organic aqueous mobile phases
Choosing Between Cyralis™ CM and Cyralis™ AM
Cyralis™ CM and Cyralis™ AM provide complementary chiral selectivity. Some racemates may separate effectively on Cyralis™ CM but show limited resolution on Cyralis™ AM. Other compounds may demonstrate the opposite behavior. When the optimal stationary phase cannot be predicted from the molecular structure of the analyte, evaluating both selectors is recommended.
