Featured Research

from universities, journals, and other organizations

Molecular mirror images assigned: Safer drugs thanks to a new solution to a 150-year-old chemistry problem?

Date:
September 13, 2013
Source:
Technische Universität Darmstadt
Summary:
Just like gloves, molecules come in so-called left-handed and right-handed versions. Until now, however, it could be determined only with great difficulty whether a certain molecule is right-handed or left-handed. Scientists now report a new solution to this 150-year old problem. In medicine, this would be a big step forward because, for example, the unwanted side effects of drugs could be avoided.

Bursting molecule: The path of the measured fragmentations (small balls) is determined by the molecular structure (big balls).
Credit: Image courtesy of Technische Universität Darmstadt

Just like gloves, molecules come in so-called left-handed and right-handed versions. Until now, however, it could be determined only with great difficulty whether a certain molecule is right-handed or left-handed. In medicine, this would be a big step forward because, for example, the unwanted side effects of drugs could be avoided. In the current issue of the journal Science, a team of researchers from Germany, Canada and Switzerland reports a new solution to a 150-year old problem.

The phenomenon of molecules with handedness is well known in yogurt: the bacterial cultures produce levo- or dextrorotatory lactic acid; of these two types, one form has a more favorable influence on intestinal flora than the other. In other substances, the second version is less harmless and causes damage: for example, while one form of penicillamine is effective against arthritis, its mirror image is more toxic.

"Enlargement" due to explosion

But how can we determine whether molecules are right- or left-handed? Until now, it was possible to directly determine handedness only in solid, crystalline substances using a special process in which the crystal structure was analyzed using X-rays. "The problem with this method is that it is not easy to crystallize every substance or to simply incorporate it into a suitable crystal. Therefore, we investigated a method in which the handedness can be determined directly in the gas phase," explains Prof. Robert Berger of the Clemens-Schöpf Institute at TU Darmstadt.

It is based on "enlargement" due to explosion. Imagine inflating a rubber glove until it bursts. If you follow the trajectory of each finger in the opposite direction, you obtain the original glove and can see whether it is a right or left glove. The researchers proceeded in a similar way for the molecules that they studied.

Their test subject was bromochlorofluoromethane, an easily evaporable liquid carbon compound with four different bonding partners. The molecule has the shape of a tetrahedron, with carbon in the middle and hydrogen, bromine, chlorine and fluorine at the corners. The handedness results from the distribution of the bonding partners on the four corners. To determine this, an intense laser beam is used to remove one type of electron from all the atoms at once. The molecule, which now has five positive charges, explodes due to the high repulsion between the positively charged modules. The particles then collide with a detector that determines the duration of the flight and the location of the impact, thus allowing the flight path to be established. From this, the spatial arrangement of the atoms in the molecule before the explosion can be reconstructed.

A variety of applications

"This method opens new perspectives for the investigation and analysis of handed molecules in physics, chemistry and pharmaceutics," predicts Dr. Markus Schöffler of the Institute of Nuclear Physics at Goethe University. For example, drugs could be produced in which only the molecules of the desired handedness are present. As a result, the dosage could be reduced. But other industries would also benefit: in carvone, a component of essential oils, for example, the handedness determines whether it smells like spearmint or caraway. In other substances, the flavor changes from bitter to sweet, for instance.

"However, being able to work only with the desired molecular type is a long-term goal," Berger points out. "We now have for the time being proved, for the textbook example of a handed substance, that direct assignment in the gas phase is possible."


Story Source:

The above story is based on materials provided by Technische Universität Darmstadt. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Pitzer, M. Kunitski, A. S. Johnson, T. Jahnke, H. Sann, F. Sturm, L. P. H. Schmidt, H. Schmidt-Bocking, R. Dorner, J. Stohner, J. Kiedrowski, M. Reggelin, S. Marquardt, A. Schiesser, R. Berger, M. S. Schoffler. Direct Determination of Absolute Molecular Stereochemistry in Gas Phase by Coulomb Explosion Imaging. Science, 2013; 341 (6150): 1096 DOI: 10.1126/science.1240362

Cite This Page:

Technische Universität Darmstadt. "Molecular mirror images assigned: Safer drugs thanks to a new solution to a 150-year-old chemistry problem?." ScienceDaily. ScienceDaily, 13 September 2013. <www.sciencedaily.com/releases/2013/09/130913085800.htm>.
Technische Universität Darmstadt. (2013, September 13). Molecular mirror images assigned: Safer drugs thanks to a new solution to a 150-year-old chemistry problem?. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2013/09/130913085800.htm
Technische Universität Darmstadt. "Molecular mirror images assigned: Safer drugs thanks to a new solution to a 150-year-old chemistry problem?." ScienceDaily. www.sciencedaily.com/releases/2013/09/130913085800.htm (accessed October 2, 2014).

Share This



More Matter & Energy News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Japan Looks To Faster Future As Bullet Train Turns 50

Japan Looks To Faster Future As Bullet Train Turns 50

Newsy (Oct. 1, 2014) — Japan's bullet train turns 50 Wednesday. Here's a look at how it's changed over half a century — and the changes it's inspired globally. Video provided by Newsy
Powered by NewsLook.com
US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) — Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) — A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) — A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins