Results promising for computational quantum chemical methods for drug development

Dec 20, 2007

New research, led by a Virginia Tech chemist, may someday help natural-products chemists decrease by years the amount of time it takes for the development of certain types of medicinal drugs. The research by T. Daniel Crawford, associate professor of chemistry, involves computations of optical rotation angles on chiral—non-superimposable—molecules. The research titled, The Current State of ‘Ab Initio’ Calculations of Optical Rotation and Electronic Circular Dichcoism Spectra, appeared recently as the cover article in The Journal of Physical Chemistry A.

Many chiral molecules are important for medical treatment for illnesses ranging from acid-reflux to cancer. The term “chiral” means that two mirror images of a molecule cannot be superimposed onto each other. In other words, some are “left-handed” and some are “right-handed.”

“Most drugs have this handedness property,” Crawford said, “and for many of these drugs, even though both hands can cause a reaction, it is a situation where one hand does a good thing and one does a bad thing.” He used thalidomide as an example. A mixture of both hands of the drug was used in the late 1950s and early 1960s to treat morning sickness in pregnant women. Later studies revealed that, while one of the two hands acted as the desired sedative, the other hand was found to cause significant birth defects. Thalidomide was never approved by the FDA in the United States and was eventually taken off the market in Europe.

For chemists, therefore, it is often vital to determine which hand of a molecule they are using. In other words, when you have a sample of a chiral molecule, how do you distinguish between the left and right hand"

This is where a technique called polarimetry comes in to play. By shooting plane-polarized light through a sample of one hand, the chiral molecule in question will rotate to a characteristic angle either clockwise or counterclockwise, and the two hands of a chiral molecule produce opposite rotations.

“So if we figure out the direction and rotation of the light or each hand, we have a frame of reference for determining whether we have the left or right hand of a molecule,” Crawford said.

The problem with this method is that synthesizing the two hands of chiral molecules is often extremely time consuming. “It can take anywhere from weeks to years,” Crawford said.

Crawford’s research applies the theory of quantum mechanics to devise computational methods in order to eliminate having to create a synthetic molecule. “The hope is that this will allow us to calculate things like optical rotation very accurately,” he said. “So when an organic chemist has a molecule and doesn’t know if it is left- or right-handed, we can calculate that directly on the computer.”

Crawford said the ultimate goal in his research is to be able to provide organic chemists with computational tools to determine the handedness of a particular molecule they are working with. He said that such tools could speed up the drug development process by years.

Source: Virginia Tech

Explore further: Oat breakfast cereals may contain a common mold-related toxin

add to favorites email to friend print save as pdf

Related Stories

New detection technologies for bacterial pathogens

Feb 19, 2015

In FP7 jargon, RAPTADIAG is categorised as a 'small or medium-scale focused research project'. However, the past two years have seen the consortium turn a novel diagnostic test for bacterial meningitis into ...

Jumping genes have essential biological functions

Feb 19, 2015

"Alu" sequences are small repetitive elements representing about 10% of our genome. Because of their ability to move around the genome, these "jumping genes" are considered as real motors of evolution. However, they were ...

Half spheres for molecular circuits

Feb 16, 2015

Corannulene is a carbon molecule with a unique shape (similar to the better known fullerene) and promising properties. A team of scientists from SISSA and the University of Zurich carried out computer simulations ...

Recommended for you

Oat breakfast cereals may contain a common mold-related toxin

Feb 25, 2015

Oats are often touted for boosting heart health, but scientists warn that the grain and its products might need closer monitoring for potential mold contamination. They report in ACS' Journal of Agricultural and Food Chemistry that s ...

NETL invents improved oxygen carriers

Feb 24, 2015

One of the keys to the successful deployment of chemical looping technologies is the development of affordable, high performance oxygen carriers. One potential solution is the naturally-occurring iron oxide, ...

Research could make blue jeans green

Feb 23, 2015

Who doesn't like blue jeans? They're practically wrinkle-proof. The indigo dye that provides their distinctive color holds up to detergents, but ages into that soft, worn look. No wonder the average American ...

Novel electrode boosts green hydrogen research

Feb 20, 2015

Scientists from the National Physical Laboratory (NPL) have developed a novel reference electrode, and are working with hydrogen energy system manufacturer ITM Power to aid the development of hydrogen production ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.