Subscribe free to our newsletters via your
. 24/7 Space News .




TECH SPACE
Princeton technique puts chemistry breakthroughs on the fast track
by Morgan Kelly
Princeton NJ (SPX) Nov 30, 2011


David MacMillan, the James S. McDonnell Distinguished University Professor of Chemistry at Princeton.

Scientists can now take that "a-ha" moment to go with a method Princeton University researchers developed - and successfully tested - to speed up the chances of an unexpected yet groundbreaking chemical discovery.

The researchers report this month in the journal Science a technique to accomplish "accelerated serendipity" by using robotics to perform more than 1,000 chemical reactions a day with molecules never before combined.

In a single day of trials, the Princeton researchers discovered a shortcut for producing pharmaceutical-like compounds that shaves weeks off the traditional process, the researchers report.

The basis of the research was to combine new technology with a unique, rapid-reaction approach that could allow chemists to explore unheard-of and potentially important chemical combinations without devoting years to the pursuit, explained senior researcher and co-author David MacMillan, the James S. McDonnell Distinguished University Professor of Chemistry at Princeton and chair of the department.

MacMillan worked with lead author Andrew McNally, a research associate in MacMillan's lab, and Princeton graduate student and co-author Christopher Prier.

"This is a very different way of approaching how we come up with valuable chemical reactions," MacMillan said.

"Our process is designed specifically for serendipity to occur. The molecules that should be combined are those for which the result is unknown," he said. "In our lab, we used this technique to make new findings in a much more routine and rapid fashion, and we show that if you have enough events involved, serendipity won't be rare. In fact, you can enable it to happen on almost a daily basis."

The MacMillan lab's technique does more than just expedite the discovery process - the researchers actually developed a unique framework for creating new materials or finding better ways of producing existing ones, said Stephen Buchwald, a professor of chemistry at the Massachusetts Institute of Technology.

"This is a particularly brilliant approach," said Buchwald, who is familiar with the work but had no role in it.

"Usually, one takes molecules that one thinks will react and tries to figure out the best way to achieve that reaction," he said. "This team took molecules for which there was no obvious reaction between them and looked for 'accidental' reactivity. This approach could be useful for any field that requires new types of matter or a more efficient means of synthesizing known compounds."

Illustrating that principle, the Princeton researchers combined two molecules with no history of reacting to generate the type of chemical functionality found in eight of the world's top 100 pharmaceuticals, MacMillan said. The reaction involved a nitrogen-based molecule known as an amine that has a hydrogen and carbon pair, and a circle of atoms stabilized by their bonds known as an aromatic ring.

The result was a carbon-nitrogen molecule with an aromatic ring, a building block of many amine-based pharmaceuticals, explained MacMillan. This class of drugs mimics natural amine molecules in the body and includes medications such as antihistamines, decongestants and antidepressants.

In drug development, chemists "tweak" organic molecules to enhance their ability to bind with and disrupt enzymes in a biological system, which is how pharmaceuticals basically operate, MacMillan said. A molecule with an aromatic ring has increased reactivity and makes the tweaking process much easier, he said, but attaching the aromatic ring is a process in itself that typically involves two to three weeks of successive chemical reactions.

The reaction MacMillan and his team found provides a quick way around that.

"We quickly realized that any pharmaceutical research chemist could immediately take these very simple components and, via a reaction no one had known about, start assembling molecules with an adjacent aromatic ring rapidly," MacMillan said.

"Instead of having to construct these important molecules circuitously using lots of different chemistry over a period of days if not weeks, we can now do it immediately in the space of one chemical reaction in one day."

Buchwald said that the rapid production of this molecule is as surprising as it is significant.

"The way these types of molecules - alpha aryl amines - were produced in this project is highly efficient, and no person could truthfully say that they would have predicted this reaction," Buchwald said. "This group was able to take a reaction that no one knew was possible and make it practical and useful in a very short time. This really speaks to the power of their overall method."

MacMillan conceived of accelerated serendipity after reflecting on his doctoral work at the University of California-Irvine during the 1990s.

His work there hinged on two unforeseen yet important reactions that occurred in the span of six years, he said. When envisioning the project reported in Science, MacMillan calculated that if, in a single day, he ran the equivalent of one reaction per day for three years - nearly 1,100 reactions - the odds favored a new discovery, he said.

The Princeton team began running reactions once a day using a high-throughput, automated reaction accelerator in Princeton's Merck Center for Catalysis, combining on a one-to-one ratio molecules with no reported affect on each other.

Central to the process is a technique developed in MacMillan's lab and reported in Science in 2008 to synthesize chemical reactions using a low-power light source, such as a household light bulb. Known as photoredox catalysis, the reaction takes place when inorganic catalysts absorb light particles from the light source then pass an electron onto the organic molecules, which creates, or synthesizes, a new compound.

For the latest work, MacMillan and his team carried out this process on the molecules before each reaction cycle. Because the use of photoredox catalysts in organic-compound synthesis is relatively new - it has been typically used by chemists and in industry for processes such as energy storage and hydrogen production - it has not been as thoroughly explored as the more common method of using catalysts derived from metals such as nickel, gold and copper, MacMillan said.

Thus, he said, elements with no history of reacting with each other could possibly produce results under this different approach.

"If one wanted to find new reactions, it would have to be done in a completely new area of chemistry research where the chances of finding something completely unknown are probably higher than continuing in an area that has been studied for the past 50 years," MacMillan said.

The Princeton researchers produced numerous new reactions, but "new" does not necessarily equal interesting or important, MacMillan said. They analyzed and experimented with each new reaction for its potential application, a process that revealed the nitrogen-carbon molecule with the aromatic ring.

An important feature of the Princeton researchers' molecule - like any important discovery - is that its application extends beyond the material itself, MacMillan said. He and his colleagues have begun mining the very process that created the molecule for indications that other novel reactions can be brought about.

"If we found this was one really valuable reaction, we wondered what others exist that we just don't know about," MacMillan said.

"Another very valuable aspect of the molecule we created is that once we understood how it happened, it set us up to design other completely new reactions based upon our understanding of what happened initially," he said. "Now, we're applying similar techniques broadly, finding new reactions continually and determining which ones are important.

"To us that really proved the point of why you want serendipitous findings," MacMillan said. "They present new knowledge, and based upon that new knowledge you can invent."

The research was published Nov. 25 in Science and was supported by a grant from the National Institutes of Health, and gifts from Merck, Amgen, Abbott and Bristol-Myers Squibb.

.


Related Links
Princeton
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Recycle this: Bolivian turns waste into high fashion
La Paz (AFP) Nov 27, 2011
Crafted from old newspapers, plastic bags, discarded CDs and soda bottle caps, Bolivian designer Marion Macedo's quirky fashion creations have added an eclectic dimension to the catwalks of Europe, South America and Asia. Each dress is a unique, eco-friendly work that takes about a week to make by hand and comes with a $250 price tag. Macedo does most of the work herself, using giant needles ... read more


TECH SPACE
Schafer Corp Signs Licensing Agreement with MoonDust Technologies

Russia wants to focus on Moon if Mars mission fails

Flying over the three-dimensional Moon

LRO Camera Team Releases High Resolution Global Topographic Map of Moon

TECH SPACE
Mars Science Laboratory Lifts Off Protected by Lockheed Martin-Built Aeroshell

Veteran Mars Researcher Says Curiosity Spacecraft Can Confirm Viking Detected Life

Los Alamos instrument to shine light on Mars habitability

NASA Launches Most Capable and Robust Rover to Mars

TECH SPACE
Nanosail-D Sails Home

Dutch astronaut's cheesy request

Looking for a Space Job

Thanksgiving in space may one day come with all the trimmings

TECH SPACE
15 patents granted for Chinese space docking technology

China plans major effort in pursuing manned space technology

Tiangong-1 orbiter enters long-term operation management

China launches two satellites: state media

TECH SPACE
Growing Knowledge in Space

MDA to extend its services to support Canadarm2 and Dextre for ISS

FLEX-ible Insight Into Flame Behavior

Satellite junk no threat to space station crew

TECH SPACE
Europe's third ATV is loaded with cargo for its 2012 launch by Arianespace

Assembly milestone reached with Ariane 5 to launch next ATV

Russia launches Chinese satellite

AsiaSat 7 Spacecraft Separation Successfully Completed

TECH SPACE
Habitable Does not Mean 'Earth-Like'

Exo planet count tops 700

Giant planet ejected from the solar system

Three New Planets and a Mystery Object Discovered Outside Our Solar System

TECH SPACE
Samsung wins reprieve in Australian tablet battle: Dow Jones

Princeton technique puts chemistry breakthroughs on the fast track

US Army And South Korean Exercises Rely on Lockheed Martin Simulation Technology

New Cosmodome brings new focus on virtual space exploration




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement