Featured Research

from universities, journals, and other organizations

Chiral Building Blocks For New Pharmaceuticals Finally Available In Large Quantities

Date:
February 4, 2008
Source:
Wiley-Blackwell
Summary:
Through a combination of one biotechnological and one chemical step, and starting from sunflower oil, scientists have devised a large-scale synthesis of (2R-3S)-isocitric acid, the last intermediate in the citric acid cycle to become available in bulk quantities. Smaller, easily accessible chiral compounds are useful building blocks for the synthesis of complex natural products and are interesting starting materials for the pharmaceutical industry. Isocitric acid makes available a new assortment of such chiral building blocks.

Through a combination of one biotechnological and one chemical step, and starting from sunflower oil, A. Giannis and co-workers from the University of Leipzig, have devised a large-scale synthesis of (2R-3S)-isocitric acid, the last intermediate in the citric acid cycle to become available in bulk quantities.

Related Articles


The citric acid cycle, one of the most important metabolic processes in our bodies, was formulated in 1937. Since then, all of the intermediates have been produced in multigram quantities—with one exception, (2R,3S)-isocitric acid. Athanassios Giannis and his team at the University of Leipzig have finally done it. Their process, a combination of one biotechnological and one chemical step, starts with sunflower oil, a renewable starting material. Isocitric acid and its derivatives thus become accessible on a kilogram scale.

In the citric acid cycle, acetyl CoA, formed in the breakdown of lipids, sugars, and amino acids, is used to produce energy that is biochemically available to an organism. Carbon dioxide and water are produced in this process. This reaction mechanism is named after one of the intermediate products, the anion of citric acid.

In nature, isocitric acid is always found with its isomer, citric acid. The difference between these two compounds is merely that the hydroxy group (-OH) is bound to a different carbon atom of each molecule. Large-scale separation of the two isomers has not been possible. A fermentative synthesis of the pure compound has also not worked.

Giannis team has now finally done it, thanks to a host of tiny helpers, the yeast Yarrowia lipolytica, which produces isocitrate from refined sunflower oil in previously unachievable yield and in a favorable isocitrate to citrate ratio. After the biomass is filtered out, electrodialysis is used to obtain the pure acids. The researchers use a trick to separate citric acid from isocitric acid: They use methanol to convert the compounds into the corresponding methyl esters. Why does this work? Whereas the citric acid ester crystallizes, the isocitric acid ester is a liquid. Separation then becomes child’s play.

Why was isocitric acid so important to these researchers? Isocitric acid is a compound with chiral centers—carbon atoms with four different groups bound to them. There are always two versions of a chiral center, one being the mirror image of the other. Smaller, easily accessible chiral compounds are useful building blocks for the synthesis of complex natural products and are interesting starting materials for the pharmaceutical industry. Isocitric acid makes available a new assortment of such chiral building blocks.

Journal reference: Syntheses with a Chiral Building Block from the Citric Acid Cycle: (2R,3S)-Isocitric Acid by Fermentation of Sunflower Oil. Angewandte Chemie International Edition. doi: 10.1002/anie.200705000


Story Source:

The above story is based on materials provided by Wiley-Blackwell. Note: Materials may be edited for content and length.


Cite This Page:

Wiley-Blackwell. "Chiral Building Blocks For New Pharmaceuticals Finally Available In Large Quantities." ScienceDaily. ScienceDaily, 4 February 2008. <www.sciencedaily.com/releases/2008/02/080204111747.htm>.
Wiley-Blackwell. (2008, February 4). Chiral Building Blocks For New Pharmaceuticals Finally Available In Large Quantities. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2008/02/080204111747.htm
Wiley-Blackwell. "Chiral Building Blocks For New Pharmaceuticals Finally Available In Large Quantities." ScienceDaily. www.sciencedaily.com/releases/2008/02/080204111747.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Don't Fall For Flu Shot Myths

Don't Fall For Flu Shot Myths

Newsy (Nov. 23, 2014) Misconceptions abound when it comes to your annual flu shot. Medical experts say most people older than 6 months should get the shot. Video provided by Newsy
Powered by NewsLook.com
WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
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


Health & Medicine

Mind & Brain

Living & Well

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