Chemists want new asymmetric catalysts because they impart handedness or chirality to the molecules they are used to make. For example, when a left-handed or right-handed catalyst is used to speed a chemical reaction, the chemical that results from that reaction can be either left-handed or right-handed.
"Handedness is an essential component of a drug's effectiveness," Sigman says.
Drugs generally work by latching onto proteins involved in a disease-causing process. The drug is like a key that fits into a protein lock, and chirality "is the direction the key goes" to fit properly and open the lock, says Sigman.
"However, developing asymmetric catalysts [to produce asymmetric drug molecules] can be a time-consuming and sometimes unsuccessful undertaking" because it usually is done by trial and error, he adds.
Sigman says the new study "is a step toward developing faster methods to identify optimal catalysts and insight into how to design them."
A Mathematical Approach to Catalyst Design
Harper and Sigman combined principles of data analysis with principles of catalyst design to create a "library" of nine related catalysts that they hypothesized would effectively catalyze a given reaction one that could be useful for making new pharmaceuticals. Essentially, they used math to find the optimal size and electronic properties of the candidate catalysts.
Then the chemists tested the nine catalysts known as "quinoline proline ligands" to determine how well their degree of handedness would be passed on to the chemical reaction products the catalysts were used to produce.
|Contact: Lee Siegel|
University of Utah