Molecules with the potential to deliver healing power to stressed cells - such as those involved in heart attacks - have been created by the researchers.

The research - done at a cellular level in the lab and far from medical reality - involves the design of organic molecules that break down to release hydrogen sulfide when triggered by specific conditions such as increased oxidative stress.

Oxidative stress damages cells and is tied especially to heart disease and cancer, as well as Alzheimer's and Parkinson's disease.

Separate portions of the research were detailed in proof-of-concept papers in the Journal of the American Chemical Society and in Angewandte Chemie, an international journal.

"We have discovered that small organic molecules can be engineered to release a molecule called carbonyl sulfide, which is the most prevalent sulfur-containing molecule in the atmosphere, but more importantly converts rapidly to hydrogen sulfide under biological conditions," said co-author on both papers. "We developed and demonstrated a new mechanism to release small molecules that provide therapeutic hydrogen sulfide."

Hydrogen sulfide, a colorless gas, has long been known for its dangerous toxicity -- and its telltale smell of rotten eggs -- in the environment, but it also is produced in mammals, including humans, with important roles in molecular signaling and cardiac health.

Initially, the, lead author of the ACS paper, used benzyl thiocarbamates to design responsive organic molecules that release carbonyl sulfide. For the second paper, researchers adapted the molecule so it remains nontoxic and stable until cellular conditions trigger it to release the carbonyl sulfide, which is converted to hydrogen sulfide by carbonic anhydrase enzymes in the body.

During a heart attack or loss of blood flow, for example, increased levels of reactive oxygen species like hydrogen peroxide emerge, co-author said. The recently developed donor molecules are programmed to react to the overexpression of reactive oxygen species. Current hydrogen sulfide donors are generally slow-release molecules that donate hydrogen sulfide passively.

Taken together, the two studies show that it's possible to build molecular scaffolds to release carbonyl sulfide and then hydrogen sulfide by creating a trigger in the molecule to start the delivery process. "The novelty for us was being able to use carbonyl sulfide as a source of hydrogen sulfide donation," said the project lead. "This was a first. It opened up a whole new class of donor molecules."

One of the goals of developing these small hydrogen sulfide-releasing molecules is the potential for long-term applications in therapeutics, co-author said.

http://around.uoregon.edu/content/designer-molecule-offers-new-hope-damaged-cells