To understand the chemical behavior of organic molecules in the space environment, amino acids and a dipeptide in pure form and embedded in meteorite powder were exposed in the PROCESS experiment in the EXPOSE-E facility mounted on the European Technology Exposure Facility (EuTEF) platform on board the International Space Station (ISS). After exposure to space conditions for 18 months, the samples were returned to Earth and analyzed in the laboratory for reactions caused by solar UV and cosmic radiation. Chemical degradation and possible racemization and oligomerization, the main reactions caused by photochemistry in the vacuum ultraviolet domain (VUV, wavelength range 100-200 nm for photon energy from 6.
View Article and Find Full Text PDFThe PROCESS (PRebiotic Organic ChEmistry on the Space Station) experiment was part of the EXPOSE-E payload outside the European Columbus module of the International Space Station from February 2008 to August 2009. During this interval, organic samples were exposed to space conditions to simulate their evolution in various astrophysical environments. The samples used represent organic species related to the evolution of organic matter on the small bodies of the Solar System (carbonaceous asteroids and comets), the photolysis of methane in the atmosphere of Titan, and the search for organic matter at the surface of Mars.
View Article and Find Full Text PDFDelivery of prebiotic molecules, such as amino acids and peptides, in meteoritic/micrometeoritic materials to early Earth during the first 500 million years is considered to be one of the main processes by which the building blocks of life arrived on Earth. In this context, we present a study in which the effects of impact shock on amino acids and a peptide in artificial meteorites composed of saponite clay were investigated. The samples were subjected to pressures ranging from 12-28.
View Article and Find Full Text PDFTwo GC-MS methods for the enantioselective separation of the 20 proteinogenic amino acids are compared. Ethyl chloroformate and 2-chloropropanol were used to derivatize amino acid enantiomers. The diastereomers formed were separated on a non-chiral column by capillary gas chromatography.
View Article and Find Full Text PDFLeucine, alpha-methyl leucine and two peptides were exposed to space conditions on board the MIR station during the Perseus-Exobiology mission. This long duration space mission was aimed at testing the delivery of prebiotic building blocks. During this mission, two amino acids (leucine and alpha-methyl leucine) and two peptides (leucine-diketopiperazine and trileucine thioethylester) were exposed in Earth orbit for three months.
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