Navigation Links
Kilogram quantities at last!

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 quantitieswith one exception, (2R,3S)-isocitric acid. Athanassios Giannis and his team at the University of Leipzig have finally done it. As they report in the journal Angewandte Chemie, 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 childs play.

Why was isocitric acid so important to these researchers" Isocitric acid is a compound with chiral centerscarbon 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.


Contact: Athanassios Giannis

Post Your Comments:
(Date:10/29/2015)...   MedNet Solutions , an innovative SaaS-based eClinical ... research, is pleased to announce that it has been ... one of only three finalists for a 2015 ... Growing" category. The Tekne Awards honor Minnesota ... innovation and leadership. iMedNet™ eClinical ...
(Date:10/29/2015)... , Oct. 29, 2015  Rubicon Genomics, ... for U.S. distribution of its DNA library preparation ... and Rubicon,s new ThruPLEX Plasma-seq kit. ThruPLEX Plasma-seq ... the preparation of NGS libraries for liquid biopsies--the ... diagnostic and prognostic applications in cancer and other ...
(Date:10/29/2015)... , Oct. 29, 2015 Today, ... announced a partnership with 2XU, a global leader ... deliver a smart hat with advanced bio-sensing technology. ... other athletes to monitor key biometrics to improve ... strategic partnership, the two companies will bring together the ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... 2015 Orexigen® Therapeutics, Inc. (Nasdaq: OREX ... fireside chat discussion at the Piper Jaffray 27th Annual ... The discussion is scheduled for Wednesday, December 2, at ... A replay will be available for 14 days after ... Julie NormartVP, Corporate Communications and Business Development , BrewLife(858) ...
(Date:11/24/2015)... ... November 24, 2015 , ... The United States Golf ... the 2016 USGA Green Section Award. Presented annually since 1961, the USGA Green Section ... her work with turfgrass. , Clarke, of Iselin, N.J., is an extension ...
(Date:11/24/2015)... ... November 24, 2015 , ... ... But unless it is bound to proteins, copper is also toxic to cells. ... at Worcester Polytechnic Institute (WPI) will conduct a systematic study of copper in ...
(Date:11/24/2015)... -- --> --> ... Market by Product & Services (Primer, Probe, Custom Oligos, ... End-User (Research, Pharmaceutical & Biotech, Diagnostic Labs) - Global ... expected to reach USD 1,918.6 Million by 2020 from ... 10.1% during the forecast period. Browse 183 ...
Breaking Biology Technology: