Washington: Two Indian-origin scientists-led team claims to have shown the plausibility of a new pathway to life's chemical building blocks, in what may help recreate the chemistry that might have allowed life to emerge on Earth.
Chemists have for long considered a chemical pathway known as the formose reaction as the only route for producing sugars essential for life to begin.
Now, Vasu Sagi along with Ramanarayanan Krishnamurthy and colleagues at Scripps Research Institute say they have found an alternative pathway to those sugars, called the glyoxylate scenario, 'Journal of the American Chemical Society' reported.
"We were working in uncharted territory. We didn't know what to expect but the glyoxylate scenario with respect to formation of carbohydrates is not a hypothesis anymore, it's an experimental fact," Krishnamurthy said.
In fact, since 2007, the scientists have been working on this new pathway -- the glyoxylate scenario which involved glyoxylate as an alternative starting point to launch a cascade of reactions that would lead to sugars.
Glyoxylate was a good starting point because of the possibility that it could be produced by oligomerisation of carbon monoxide under potentially prebiotic conditions, say the scientists.
The team began developing the experiments to test the hypothesis. At the time, very little was known about relevant reactions involving DHF, and nothing beyond theory about how it reacted with glyoxylate.
The experiments revealed that under the right conditions, DHF and glyoxylate, when in the presence of a few other plausible prebiotic chemicals including formaldehyde, would produce sugars known as ketoses.
Ketoses in turn can be converted to critical sugars, including some essential to forming certain amino acids, the DNA and RNA building blocks such as ribose.
In remarkable contrast to the formose reaction, which might only convert a fraction of a percent of its starting materials into ribose, the experiments converted virtually 100 percent of the glyoxylategave conversion of DHF to ketoses.
Such efficiency is so rare in prebiotic chemistry and was so unexpected in the glyoxylate dihydroxyfumarate experiments, that the scientists were leery at first of their results. "We had to prove it by repeating the experiments many times," Sagi said in a release by the institute.
PTI
First Published: Wednesday, February 01, 2012, 13:06