The X-ray emission of the young Sun was much harder and intense than today and might have played a significant role in the evolution of complex organics in protoplanetary environments. We investigate the effects of soft X-rays on tryptophan molecules in aqueous solutions at room temperature. As results of the irradiation experiments we detect several light species indicative of fragmentation, together with large molecular structures such as tryptophan dipeptide and tripeptide. Complexification is more evident in H2O solution than in D2O, probably due to isotopic effects. The abundances of peptides depend on the irradiation dose and decrease with increasing energy deposition. Radicals such as D, OD, H and OH, induced by the X-ray interaction with solvents, play a major role in determining the final products.
|Numero di pagine||9|
|Rivista||International Journal of Astrobiology|
|Stato di pubblicazione||Published - 2011|
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Physics and Astronomy (miscellaneous)
- Space and Planetary Science
- Earth and Planetary Sciences (miscellaneous)
Indelicato, S., Bongiorno, D., Barbera, M., La Barbera, Mingoia, F., Collura, Cecchi-Pestellini, Ciaravella, & Testa (2011). The young hard active Sun: soft X-ray irradiation of tryptophan in water solutions. International Journal of Astrobiology, 10, 67-75.