Chiral Separation

Chiral drugs are a subgroup of drug substances that contain one or more chiral
centers. From the points of view of safety and efficacy, the pure enantiomer is preferred over the racemate in many marketed dosage forms. Thus, resolution of enantiomer mixtures is an active area of research.

In our research, we used chiral self assembled monolayers (SAMs) on gold as resolving auxiliaries in the crystallization of the amino acid valine. We were able to obtain one enantiomer in excess on the crystals obtained on the chiral SAMs when starting with racemic solutions. The enantiomer obtained in excess was the one having opposite chirality to the monolayer being used. Significantly, we
were also able to obtain crystals of the pure enantiomer when starting with a solution having an enantiomeric excess value of 50%.