Navigation Links
Chiral metal surfaces may help to manufacture pharmaceuticals
Date:10/26/2011

New research shows how metal surfaces that lack mirror symmetry could provide a novel approach towards manufacturing pharmaceuticals.

These 'intrinsically chiral' metal surfaces offer potential new ways to control chiral chemistry, pointing to the intriguing possibility of using heterogeneous catalysis in drug synthesis. Such surfaces could also become the basis of new biosensor technologies.

A chiral object, such as your hand, is one that cannot be superposed on its mirror image. Chirality is fundamental in biochemistry. The building blocks of life - amino acids and sugars - are chiral molecules: their molecular structures can exist in either "left-handed" or "right-handed" forms (or "enantiomers").

A living organism may respond differently to the two enantiomers of a chiral substance. This is crucially important in the case of pharmaceutical drugs, where the therapeutic effect is often tied strongly to just one enantiomer of the drug molecule. Controlling chirality is therefore vital in pharmaceutical synthesis.

Research into controlling chiral synthesis focuses mainly on using homogeneous catalysts, where the catalyst is in the same phase as the reactants and products, such as a liquid added to a liquid-phase reaction. However, this poses significant practical challenges in recovering the valuable catalyst material from the mixture. To avoid this problem, an attractive alternative would be heterogeneous catalysis over a solid surface - the type of catalysis used in catalytic converters in car exhaust systems, as well as in industrial Haber-Bosch synthesis of ammonia and Fischer-Tropsch synthesis of synthetic fuel, for example. The question then is how to achieve enantiomer-specific effects at a surface.

To help answer this question, scientists at the University of Cambridge have been probing the spontaneous self-organization of a simple chiral amino acid, alanine, into regular molecular arrays on copper single-crystal surfaces. Thanks to a powerful scanning tunnelling microscope, capable of resolving individual atoms and molecules, their work is revealing the various manifestations of chirality that occur, giving important clues to how they arise, and how they might be controlled and exploited.

Dr Stephen Driver, of the Department of Chemistry at the University of Cambridge, who led the experimental work, said: "We set out to investigate two distinct scenarios. In one scenario, the surface is non-chiral, so any chirality that we see can only arise from the chirality of the alanine molecule. In the other scenario, we move to a surface that is intrinsically chiral. Now the question becomes: do the two enantiomers of alanine behave differently on this chiral surface?"

On the non-chiral surface, the researchers found that alanine can self-organise into either of two patterns. In one of these, the self-organisation is driven by hydrogen bonding between the molecules, while the chiral centre has no discernable impact on the regular array. In the other structure, a network of long-range chiral boundaries punctuates the array, and the boundary chirality switches with molecular chirality.

Driver explained: "The implication is that the chiral centre is having a direct influence on the packing of two alanine neighbours at the boundary, and that the chirality of this pair propagates to the next pair and the next and so on, so that the chiral boundary is built up over a long range."

The chiral surface is created simply by choosing a surface orientation that lies away from any of the bulk mirror symmetry planes of the metal crystal. When the researchers added alanine, they found that the surface changes its local orientation, forming nanometre-scale facets. The two enantiomers of alanine self-organise into different chiral patterns: a strong, enantiomer-specific structural effect. This "proof of principle" could potentially be exploited in chiral recognition, in chiral synthesis (forming a chiral product from non-chiral reactants), and in chiral separations.

Driver added: "It looks like alanine can shape a comfortable, chiral bonding site for itself. The copper surface has the flexibility to adapt itself to the shape of the alanine molecule, and this shape is different for the two different molecular enantiomers."

The results imply that certain surface orientations will form stable, ordered structures with one molecular enantiomer but not the other: exactly the right conditions to promote chiral chemical effects.

Professor Sir David King, former Chief Scientific Advisor to the UK Government and current Director of the Smith School of Enterprise and the Environment at Oxford, brought together the team carrying out this research. "These results are very exciting," said King. "Tailoring the right surface to the right molecule should lead to strong enantiospecific effects. We see a real basis here for a breakthrough technology in the pharmaceuticals sector. It's something that pharma companies should be taking a close interest in."

The Cambridge team's findings are published in Topics in Catalysis.


'/>"/>
Contact: Genevieve Maul
Genevieve.maul@admin.cam.ac.uk
44-012-237-65542
University of Cambridge
Source:Eurekalert

Related medicine news :

1. New Delhi metallo-beta-lactamase-1 enzyme acquired in Canada
2. LED products billed as eco-friendly contain toxic metals, study finds
3. Red mud disasters main threat to crops is not toxic metals
4. Metal Tongue Piercings Linked to Raised Infection Risks
5. New York Personal Injury Attorney David Perecman Comments On Dangers Of ‘Metal On Metal' Hip Implants
6. Parallels Launches Parallels Server for Mac Bare Metal Edition
7. Phoenix Volleyball Festival Championships Played on SnapSports Volleyball Surfaces
8. Long struggle for appropriately processed manufacturer data leads to a new assessment of memantine
9. Center to revolutionize chemical manufacture is open for business
10. Bling My Sling LL Announces Website Launch - A fashionable arm sling manufacturer, announce the opening of their new website bling-my-sling.com
11. Linguistics professor examines manufacturers prescription drug websites
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/12/2017)... ... 2017 , ... Dr. Parsa Mohebi, the Los Angeles based ... the newly revamped Cosmetic Town journal section, featuring articles written by ... as Follicular Unit Extraction (FUE). , Dr. Mohebi says “I enjoy ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... Leading pediatric ... peers in Washington, D.C., for the 49th Congress of the International Society of ... Vice President of the Center for Cancer and Blood Disorders at Children’s ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... been named one of Michigan’s 2017 Best and Brightest in Wellness® by Best ... in Wellness® awards program on Friday, Oct. 20 from 7:30 a.m. to 2 ...
(Date:10/12/2017)... ... October 12, 2017 , ... In the United States, single-family ... some states—like New York, New Jersey, Massachusetts, Texas, Virginia, Connecticut, and California—the average ... extremely low property-tax rates, which contributes to the relatively lower cost of living ...
(Date:10/12/2017)... , ... October 12, 2017 , ... ... at the University of California Berkeley, and other leading institutions in announcing the ... power of institutions to change the way animals are raised for food. , ...
Breaking Medicine News(10 mins):
(Date:9/23/2017)... Sept. 22, 2017 Janssen Biotech, Inc. (Janssen) ... letter from the U.S. Food and Drug Administration (FDA) ... sirukumab for the treatment of moderately to severely active ... clinical data are needed to further evaluate the safety ... active RA. ...
(Date:9/19/2017)... ZirMed Inc ., a recognized leader in cloud-based revenue cycle ... ranked #1 by its users for the seventh consecutive year ... ZirMed was recognized as the top-ranked end-to-end revenue cycle management ... 200 beds and holds one of the longest #1 ranking ... ...
(Date:9/12/2017)... and NEW YORK , Sept. 12, 2017 /PRNewswire/ ... ratings for global supply chains, has published the first annual edition of ... performance of more than 20,400 companies evaluated by EcoVadis, based on Scorecard ... and 2016. ... Global CSR Risk & Performance Index ...
Breaking Medicine Technology: