Metal-organic frameworks could cut chiral chromatography costs

In drug discovery, separating enantiomers of a compound usually involves high-performance liquid chromatography (HPLC) columns packed with specialized chiral stationary phases. These columns are usually compatible with only polar or nonpolar solvent mixtures, meaning chemists sometimes have to switch between columns to find the right solvent system. Now, a team of researchers has demonstrated a reusable and scalable metal-organic framework (MOF) that can do chiral separations with both polar and nonpolar solvents (J. Am. Chem. Soc. 2019, DOI: 10.1021/jacs.9b06500). José Ramón Galán-Mascarós of the Institute of Chemical Research of Catalonia and colleagues synthesized a water-stable MOF composed of copper atoms linked with modified l-histidine molecules. Galán-Mascarós’s lab teamed up with Melissa M. Reynolds of Colorado State University and other collaborators and showed that an HPLC column packed with this MOF could separate the enantiomers of the pain-relieving drug ibuprofen and the infamous medication thalidomide, which was used to treat morning sickness until scientists discovered that one of its enantiomers could cause birth defects. They also found that the column performed as well as three commercial columns at separating a reference racemic mixture. Using the MOF-packed column, however, researchers could switch among solvent systems simply by flushing the column with the appropriate solvent.