Taming a poison: Saving plants from cyanide with carbon dioxide

(Press-News.org) The scientific world is one step closer to understanding how nature uses carbon-capture to tame poisons, thanks to a recent discovery of cyanoformate by researchers at Saint Mary's University (Halifax, Canada) and the University of Jyväskylä (Finland). This simple ion — which is formed when cyanide bonds to carbon dioxide — is a by-product of the fruit-ripening process that has evaded detection for decades.

Chemists have long understood the roles presence of cyanide (CN−) and carbon dioxide (CO2) in fruit ripening, but have always observed them independently. This is the first time scientists have isolated the elusive cyanoformate anion (NCCO2−) and characterized its structure using crystallography and computational chemistry.

The results of the two-year study led by Dr. Jason Clyburne, Saint Mary's University, and Dr. Heikki M. Tuononen, University of Jyväskylä, were released today in Science, the world's preeminent scientific journal.

Their findings demonstrate the profound effect the surrounding medium has on the stability of cyanoformate. This situational stability allows carbon dioxide to deactivate cyanide's toxic capabilities at the enzyme's active site where chemical reactions take place. Subsequently, the cyanoformate migrates to the cytoplasm of the cell where it breaks down, releasing the toxic cyanide at a location where it can be dealt with. While this explains how the formation of cyanide does not halt the fruit ripening process, the implications extend far beyond plants and a single enzyme. Recognizing the factors governing the stability of cyanoformate furthers our understanding of carbon-capture, a process used to trap and store carbon dioxide in the environment.

"Here we have a perfect example of nature taming a poison, and what better way to learn the chemistry of carbon-capture than from nature itself?" says Dr. Jason Clyburne, Canada Research Chair in Environmental Science and Materials, and professor of Environmental Science and Chemistry at Saint Mary's University.

"One of the biggest challenges in carbon capture is finding a material that not only captures CO2, but easily releases it," says Luke Murphy, a Masters of Science candidate at Saint Mary's who prepared the crystalline material for the study. "Cyanoformate does both and can be used as a model to develop a greener alternative."

This discovery highlights the importance of applied chemistry to other areas of science and indicates there is still more to be learned about the chemistry of carbon dioxide in cells.

"The fact that cyanoformate was undetected for so long begs the question: What other simple chemistry have we missed?" asks Dr. Heikki M. Tuononen, Academy of Finland research fellow, and senior lecturer at University of Jyväskylä, Finland.

INFORMATION: More information, including a copy of the paper, can be found online at the Science press package at http://www.eurekalert.org/jrnls/sci. You will need your user ID and password to access this information.

Dr. Jason Clyburne is widely recognized as a leader in the study of green chemistry, particularly in the field of ionic liquids. In addition to holding a Canada Research Chair in Environmental Science and Materials at Saint Mary's University (Nova Scotia, Canada), Dr. Clyburne is an adjunct professor at Simon Fraser University and Section Co-Chair of the Inorganic Chemistry Evaluation Group with the Natural Sciences and Engineering Council of Canada.

Dr. Heikki M. Tuononen is an expert in computational chemistry, particularly in the field of main group systems. He currently holds a senior lectureship and an Academy of Finland research fellowship at the Department of Chemistry, University of Jyväskylä (Finland). Dr. Tuononen is also an adjunct professor in computational inorganic chemistry at University of Oulu.

Contributors: Based upon theoretical work conducted by Dr. Jani Moilanen at University of Jyväskylä (Finland), the cyanoformate anion was predicted to be a fragile, yet marginally stable synthetic target, which made it difficult to create in the lab. Luke Murphy, a Master of Applied Science candidate at Saint Mary's University, prepared the fragile crystalline material, and Saint Mary's research associate Dr. Katherine Robertson determined its structure. The atomic connectivity of the anion was successively confirmed with modern spectroscopic methods in collaboration with Scott Harroun from Dr. Christa Brosseau's laboratory at Saint Mary's and Dr. Ulrike Werner-Zwanziger from the solid-state Nuclear Magnetic Resonance Resource (NMR-3) at Dalhousie University (Halifax, Canada).

Support for this research was provided by Dr. Jason Clyburne's Discovery Grant from the Natural Sciences and Engineering Research Council of Canada and Dr. Heikki M. Tuononen's research grants from the Academy of Finland and the Technology Industries of Finland Centennial Foundation. Additional funding was provided by GreenCentre Canada, Encana Corporation (Deep Panuke Education & Training and Research & Development Fund), Springboard, and Dr. Jani Moilanen's postdoctoral scholarship from the Magnus Ehrnrooth Foundation.