How did life begin? How did chemical reactions on the early Earth create the complex self-replicating structures that evolved into living things as we know them? According to one school of thought, before the current era of life, there was a molecule called RNA (or ribonucleic acid) that was based on DNA. Still an important component of life today, RNA can self-replicate and catalyze other chemical reactions.

But RNA molecules are composed of smaller components called ribonucleotides. How did these building blocks first form on Earth and later evolve into RNA? Chemists like me are trying to recreate the chain of reactions needed to create RNA at the beginning of life, but it’s a daunting task. We know that any chemical reaction that leads to the formation of ribonucleotides would have occurred billions of years ago in the intricate and complex environment that existed on our planet.

I investigated whether “autocatalytic” reactions might play a role. These are reactions that produce chemicals that trigger the same reaction; This means they can be sustained under a wide range of conditions. In our recent work, my colleagues and I integrated autocatalysis into a well-known chemical pathway for the production of ribonucleotide building blocks; This could probably happen with simple molecules and the complex conditions that existed on early Earth.

Formative reaction

Autocatalytic reactions play a crucial role in biology, from regulating heartbeats to creating patterns in seashells. In fact, the replication of life, in which one cell produces two cells by taking nutrients and energy from its environment, is a particularly complex example of autocatalysis.

First discovered in 1861, a chemical reaction called the formic reaction is one of the best examples of an autocatalytic reaction that may have occurred on early Earth.

Essentially, the formosa reaction begins with one molecule of a simple compound called glycolaldehyde (composed of hydrogen, carbon, and oxygen) and ends with two molecules. The mechanism is based on the constant supply of another simple compound called formaldehyde. The reaction between glycaldehyde and formaldehyde creates a larger molecule by splitting parts that feed back and drive the reaction. However, when the formaldehyde runs out, the reaction stops and the products begin to break down into resin from complex sugar molecules.

The formose reaction shares some common components with the well-known chemical pathway for the formation of ribonucleotides known as the Powner-Sutherland pathway. But so far no one has tried to combine the two; There’s a good reason for this. The Formosan reaction is known for being “indiscriminate.” This means it produces a lot of unnecessary molecules as well as the actual products you need.

Autocatalytic conversion on the way to ribonucleotides

In our study, we tried to add a simple molecule called cyanamide to the Formosa reaction. This makes it possible to “pump out” some of the molecules formed during the reaction to yield ribonucleotides. The reaction still does not produce large amounts of ribonucleotide building blocks. However, what they produce is more stable and less prone to degradation.

The integration of the formizing reaction and ribonucleotide production in our study is interesting. Previous studies have considered each separately; This reflects how chemists generally think about creating molecules.

Generally speaking, chemists try to avoid complexity to maximize product quantity and purity. However, this reductionist approach may prevent us from exploring dynamic interactions between different chemical pathways. These interactions, which occur everywhere in the real world outside the laboratory, are perhaps the bridge between chemistry and biology.

Industrial Application

Autocatalysis also has industrial applications. Another product that results when you add cyanamide to the Formosa reaction is a compound called 2-aminooxazole, which is used in chemical research and in the production of many pharmaceuticals.

The traditional production of 2-aminooxazole often uses cyanamide and glycolaldehyde; The latter is expensive. If this could be done using the formose reaction, only a small amount of glycolaldehyde would be needed to start the reaction, reducing costs.

Our laboratory is currently optimizing this procedure in the hope that we can manipulate the autocatalytic reaction to make common chemical reactions cheaper and more efficient and make pharmaceutical products more accessible. This may not be as important as the creation of life, but we still think it’s worth considering. Source