An international group of astrochemists has discovered the presence of ethanolamine, a molecular species involved in the formation of cell membranes, in an interstellar cloud of our galaxy. The abundance of ethanolamine with respect to water detected in the interstellar medium shows that this molecule formed in space and that it was probably transported to Earth subsequently with meteorite impacts
Using the Spanish radio telescopes Iram of 30 meters and Yebes of 40 meters, a group of researchers led by Víctor M. Rivilla , of the Centro de Astrobiología ( Cab, Csic-Inta) d i Madrid and associated with Inaf, has identified an additional prebiotic molecule – in addition to those already known – in the interstellar cloud G + 0.693-0.027, located in the heart of the Milky Way about 30 thousand light years from Earth. This is the chemical compound called ethanolamine ( NH 2 CH 2 CH 2 OH), the simplest “head” of phospholipids, that is, the building blocks of cell membranes that may have given rise to life on Earth. The results of the study were published in the journal Proceedings of the National Academy of Sciences and “indicate that ethanolamine forms efficiently in interstellar space, specifically in molecular clouds where new stars and planetary systems are born,” explains Rivilla, the first author of the article.
The emergence of cell membranes represents a crucial step in the origin and early evolution of life on Earth , as they hold together the genetic material and the metabolic system. The origin of these molecules, however, is still an enigma today. The abundance of ethanolamine with respect to water found in the interstellar medium (the “reservoir” that powers the formation of stars and planets in the Universe) shows that this molecule formed in space and was probably transported to Earth subsequently.
“We know that a large repertoire of prebiotic molecules may have been delivered to the early Earth through the bombardment of comets and meteorites,” says Izaskun Jiménez-Serra , one of the work’s co-authors and researcher at the CAB (Csic-Inta). “We estimate that around one million billion liters of ethanolamine may have been transported to primitive Earth by meteorite impacts. The volume is equal to all the water present in Lake Victoria, the largest African lake by extension, ”adds Jiménez-Serra.
Experiments simulating the chemical constraints of the primitive Earth confirm that ethanolamine could have produced phospholipids in those early stages. Carlos Briones , a biochemist from Cab (Csic-Inta) and co-author of the paper, comments: ‘The availability of ethanolamine on primitive Earth, along with amphiphilic fatty acids or alcohol, may have contributed to the assembly and early evolution of cell membranes. primordial and this would have important implications not only for the study of the origin of life on Earth, but also on other habitable planets and satellites in the Universe ».
This molecule on Earth is a noxious and irritating colorless liquid with an ammonia-like odor. Transformed into other compounds, it functions as a cleaning agent in the surfactant category, and is also used in personal care products and cosmetics.
The hunt for new prebiotic molecules in the interstellar medium does not stop there. “Thanks to the improved sensitivity of the current and next generation of radio telescopes, we will be able to detect molecules of increasing complexity in space, direct precursors of the three fundamental components of life: lipids (which form membranes), nucleotides of Rna and DNA (which contain genetic information), and proteins (which are responsible for metabolic activity), ”Rivilla emphasizes. “Are there these prebiotic seeds distributed all over the Galaxy, and also in other galaxies? We will know relatively soon », he concludes.
Featured image: Graphical representation of the chemical compound called ethanolamine (NH2CH2CH2OH), the simplest head of phospholipids, building blocks of cell membranes. The molecule was identified in the molecular cloud G + 0.693-0.027, located in the center of the Milky Way. Credits: Víctor M. Rivilla & Carlos Briones (Centro de Astrobiología, Csic-Inta) / Nasa Spitzer Space Telescope, Irac4 camera (8 micron)
To know more:
- Read on Proceedings of the National Academy of Sciences the article ” Discovery in space of ethanolamine, the simplest phospholipid head group ” , by Víctor M. Rivilla, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Carlos Briones, Lucas F. Rodríguez- Almeida, Fernando Rico-Villas, Belén Tercero, Shaoshan Zeng, Laura Colzi, Pablo de Vicente, Sergio Martín and Miguel Requena-Torres, was published in the magazine
Provided by INAF