Astec CHIROBIOTIC™ R

Features

• Covalently bonded glycopeptide - Ristocetin A
• Multi-modal - operates in normal, reversed and polar organic phase
• Targets anionic chiral molecules
• Complementary to CHIROBIOTIC V and CHIROBIOTIC T

CHIROBIOTIC R is one of the HPLC phases utilizing macrocyclic glycopeptides as chiral selectors. Ristocetin A has been covalently bonded to a 5 micron silica support resulting in the largest and most complex of these products.

As with CHIROBIOTIC V and CHIROBIOTIC T, CHIROBIOTIC R has the mechanisms to obtain selectivity in all three modes: polar organic; reversed phase; and, normal phase. These interactions have been identified as hydrophobic or dispersive, π-π, electrostatic, hydrogen bonding, dipole and steric. Combinations of these interactions are driven by the type of mobile phase used. Statistically, it has been shown that the normal phase type interactions driven by polar organic mode have the highest potential for separation. This is followed by reversed phase and, finally, by typical normal phase solvents like hexane/ethanol.

The main area of interaction appears to be the amine function of Ristocetin A and, as a result, this stationary phase has a particular selectivity for anionic analytes. This phase also shows good selectivity for di- and tripeptides. The D terminal dipeptides are retained longer than the L terminal. In general, the CHIROBIOTIC R has the best selectivity for α-hydroxy acids, substituted aliphatic acids, chiral alcohols, secondary and tertiary amines.