Chirality is an unusual aspect of chemistry, a seemingly minor detail with surprisingly far-reaching consequences in physical, chemical, and biological systems. Approximately 50% of drugs on the market today contain at least one chiral center. Many of these compounds exhibit pharmacological asymmetry, having one pharmaceutically useful enantiomer (known as an eutomer) and one or more enantiomers that are nonbeneﬁcial or possibly harmful (distomers). Most chemical processes produce a racemic mixture of enantiomers. The various types of enantiomers have the same physical properties, making their separation very difficult and costly. Consequently, the market price of eutomers per mass unit is often 10-200 times higher than that of the racemic mixture of the eutomer and the distomer.
Our technology takes mixtures of enantiomers and enriches the relative concentration of a selected enantiomer (the eutomer) by photocatalytic mineralization of the unwanted enantiomers. This is done by imprinting the distomer molecules onto the surface of a photocatalyst, and limiting the photocatalytic degradation only to the molecularly-imprinted sites (thus preventing the degradation of the eutomers) by virtue of forming an ultrathin inert layer in between the imprinted sites.
- The approach is generic and may operate on a large variety of molecules, unlike current methods such as asymmetric reactions or multiple-crystallization which are very specific and may require very long process time
- Up-scaling is straight forward, unlike separation of enantiomeric mixtures by chromatography, which suffers from low throughput
Applications and Opportunities
- Can be applied to produce large number of high-value biologically-active substances from their low-cost racemic mixtures.