The sign on the specific rotation of the mixture tells us which enantiomer is in excess. The positive sign on the observed specific rotation of the mixture tells us that the R-configured isomer is in excess. Calculate the enatiomeric composition of the S and R-isomers. Either a chiral reactant, a solvent, or an enzyme must exert an influence on the reaction which leads to this kind of selectivity. Many enzymatically controlled reactions will produce enantioselective results.
Chiral Drugs are enantiomers that are used instead of the racemic form of the drug.
For many years, the Pharmacological industry used the racemic form of drugs like Ibuprofen. This does take time so the pharmacological activity is slower in the racemic form of the drug than if the S-isomer was used exclusively. It is faster acting in a pure S-isomer form. Penicillamine is used as a therapeutic agent for chronic arthritus but only the S-isomer relieves this dibilatating disease. Return to the top of the page.