scholarly journals Experimental verification of photostability for free- and bound-amino acids exposed to γ-rays and UV irradiation

2004 ◽  
Vol 56 (7) ◽  
pp. 669-674 ◽  
Author(s):  
Yoshinori Takano ◽  
Takeo Kaneko ◽  
Kensei Kobayashi ◽  
Daisuke Hiroishi ◽  
Hidematsu Ikeda ◽  
...  
Keyword(s):  
Amino Acids ◽  
Uv Irradiation ◽  
Experimental Verification ◽  
Γ Rays

Formation of Amino Acids from Possible Interstellar Media by γ-rays and UV Irradiation

2002 ◽  
Vol 31 (10) ◽  
pp. 986-987 ◽  
Author(s):  
Yoshinori Takano ◽  
Hitomi Masuda ◽  
Takeo Kaneko ◽  
Kensei Kobayashi
Keyword(s):  
Amino Acids ◽  
Uv Irradiation ◽  
Interstellar Media ◽  
Γ Rays

Search for molecular biosignatures on Mars: laboratory simulations of UV irradiation of molecule-mineral complexes

2021 ◽  
Author(s):  
Teresa Fornaro ◽  
Giovanni Poggiali ◽  
Maria Angela Corazzi ◽  
Cristina Garcia ◽  
Giulia Dimitri ◽  
...  
Keyword(s):  
Amino Acids ◽  
Organic Compounds ◽  
Uv Irradiation ◽  
Organic Molecules ◽  
Spectroscopic Characterization ◽  
Sample Return ◽  
Laboratory Simulations ◽  
Prebiotic Molecules

<div> </div> <p><strong>Abstract</strong></p> <p>We present laboratory activities of preparation, characterization, and UV irradiation processing of Mars soil analogues, which are key to support both in situ exploration and sample return missions devoted to detection of molecular biosignatures on Mars.</p> <p>In detail we prepared analog mineral samples relevant to the landing sites of past, present and future Mars exploration missions, such as Gale Crater, Jezero Crater, and Oxia Planum. We doped these samples with a large variety of organic molecules (both biotic and prebiotic molecules) like amino acids, nucleotides, monosaccharides, aldehydes, lipids. We investigated molecular photostability under UV irradiation by monitoring in situ possible modifications of infrared spectroscopic features. These investigations provide pivotal information for ground analysis carried out by rovers on Mars.</p> <p><strong>Introduction</strong></p> <p>Laboratory simulations of Mars are key to support the scientific activity and technology development of life detection instruments on board present and upcoming rover missions such as Mars2020 Perseverance [1] and ExoMars2022 Rosalind Franklin [2]. Studies about the stability of organic molecules in a Martian-like environment allow us to explore the conditions for the preservation of molecular biosignatures and develop models for their degradation in the Martian geological record. A systematic study of the effects of UV radiation on a variety of molecule-mineral complexes mimicking Martian soil can be key for the selection of the most interesting samples to analyse in situ or/and collect for sample return. Testing the sensitivity of different techniques for detection of the diagnostic features of molecular biosignatures embedded into mineral matrices as a function of the molecular concentration helps the choice, design and operation of flight instruments, as well as the interpretation of data collected on the ground during mission operative periods.</p> <p><strong>Methods</strong></p> <p>Experimental analyses were conducted in the Astrobiology Laboratory at INAF-Astrophysical Observatory of Arcetri (Firenze, Italy). Laboratory activities pertain to: (i) synthesis of Mars soil analogues doped with organic compounds that are considered potential molecular biosignatures; (ii) UV-irradiation processing of the Mars soil analogues under Martian-like conditions; and (iii) spectroscopic characterization of the Mars soil analogues.</p> <p><strong>Results</strong></p> <p>Such studies have shown to be very informative in identifying mineral deposits most suitable for preservation of organic compounds, while highlighting the complementarity of different techniques for biomarkers detection, which is critical for ensuring the success of space missions devoted to the search for signs of life on Mars.</p> <p>We will present a series of laboratory results on molecular degradation caused by UV on Mars and possible application to detection of organics by Martian rovers [3,4,5,6]. In detail, we investigated the photostability of several amino acids like glycine, alanine, methionine, valine, tryptophan, phenylalanine, glutamic acid, prebiotic molecules like urea, deoxyribose and glycolaldehyde, and biomarkers like nucleotides and phytane adsorbed on relevant Martian analogs. We monitored the degradation of these molecule-mineral complexes through in situ spectroscopic analysis, investigating the reflectance properties of the samples in the NIR/MIR spectral region. Such spectroscopic characterization of molecular alteration products provides support for two upcoming robotic missions to Mars that will employ NIR spectroscopy to look for molecular biosignatures, through the instruments SuperCam on board Mars 2020, ISEM, Ma_MISS and MicrOmega on board ExoMars 2022.</p> <p><strong>Acknowledgements</strong></p> <p>This research was supported by the Italian Space Agency (ASI) grant agreement ExoMars n. 2017-48-H.0.</p> <p><strong>References</strong></p> <p>[1] Farley K. A. et al. (2020) Space Sci. Rev. 216, 142.</p> <p>[2] Vago, J. L. et al. (2017) Astrobiology 6, 309–347.</p> <p>[3] Fornaro T. et al. (2013) Icarus 226, 1068–1085.</p> <p>[4] Fornaro T. et al. (2018) Icarus 313, 38-60.</p> <p>[5] Fornaro T. et al. (2020) Front. Astron. Space Sci. 7:539289.</p> <p>[6] Poggiali G. et al. (2020) Front. Astron. Space Sci. 7:18.</p>

Laboratory simulation of UV irradiation from the Sun on amino acids. I: irradiation of tyrosine

2007 ◽  
Vol 6 (2) ◽  
pp. 123-129 ◽  
Author(s):  
F. Scappini ◽  
F. Casadei ◽  
R. Zamboni ◽  
S. Monti ◽  
P. Giorgianni ◽  
...  
Keyword(s):  
Amino Acids ◽  
Uv Irradiation ◽  
Degradation Products ◽  
Building Blocks ◽  
Laboratory Simulation ◽  
The Sun ◽  
Primitive Earth ◽  
Laboratory Results ◽  
Building Capability ◽  
Primordial Life

AbstractThe effects of ultraviolet (UV) irradiation on water solutions of tyrosine (HO—C6H4—CH2—CHNH2—COOH) have been investigated using a Xe lamp in the region 200–800 nm. This is a step in laboratory simulation towards reproducing the action of the Solar radiation on the building blocks of life, specifically α-amino acids, in the primitive Earth anoxic conditions. Results are presented showing the photostability of tyrosine against different UV doses. Degradation products partly maintain life building capability and partly do not. A tendency towards structure complexification was observed. The analysis of the irradiated tyrosine solutions was conducted using various spectroscopic and analytic techniques. The laboratory results are discussed in the light of a primordial life-emerging scenario.

Formation of complex organic molecules in astrophysical environments: Sugars and derivatives

2019 ◽  
Vol 15 (S350) ◽  
pp. 123-126
Author(s):  
Michel Nuevo ◽  
George Cooper ◽  
John M. Saunders ◽  
Christina E. Buffo ◽  
Scott A. Sandford
Keyword(s):  
Amino Acids ◽  
Uv Irradiation ◽  
Laboratory Experiments ◽  
Organic Molecules ◽  
Formation Mechanisms ◽  
Sugar Alcohols ◽  
Amphiphilic Compounds ◽  
Uv Photons ◽  
Sugar Derivatives ◽  
Complex Organic

AbstractCarbonaceous meteorites contain a large variety of complex organic molecules, including amino acids, nucleobases, sugar derivatives, amphiphiles, and other compounds of astrobiological interest. Photoprocessing of ices condensed on cold grains with ultraviolet (UV) photons was proposed as an efficient way to form such complex organics in astrophysical environments. This hypothesis was confirmed by laboratory experiments simulating photo-irradiation of ices containing H2O, CH3OH, CO, CO2, CH4, H2CO, NH3, HCN, etc., condensed on cold (~10–80 K) substrates. These experiments resulted in the formation of amino acids, nucleobases, sugar derivatives, amphiphilic compounds, and other organics comparable to those identified in carbonaceous meteorites. This work presents results for the formation of sugars, sugar alcohols, sugar acids, and their deoxy variants from the UV irradiation of ices containing H2O and CH3OH in relative proportions 2:1, and their comparison with meteoritic data. The formation mechanisms of these compounds and the astrobiological implications are also discussed.

Phytoalexine mit Indolstruktur aus Kohlrabi {Brassica oleracea var. gongylodes)+ / Indole Phytoalexins from the Kohlrabi (Brassica oleracea var. gongylodes)+

1994 ◽  
Vol 49 (5-6) ◽  
pp. 281-285 ◽  
Author(s):  
Dieter Gross ◽  
Andrea Porzel ◽  
Jürgen Schmidt
Keyword(s):  
Amino Acids ◽  
Brassica Oleracea ◽  
Uv Irradiation ◽  
Spectroscopic Data ◽  
Tuber Tissue ◽  
Indole Phytoalexins

Abstract UV-irradiation of sliced stem tubers of kohlrabi (Brassica oleracea var. gongylodes) followed by incubation for 4 days, resulted in the production of two new sulphur-containing indole phytoalexins, cyclobrassinone and 1 -methoxyspirobrassinin, whose structures were elucidated on the basis of spectroscopic data. Three known indole phytoalexins, spirobrassinin, methoxybrassitin and methoxybrassinin, and several m inor phytoalexin-like compounds not yet identified were also isolated. The accumulation of these indole phytoalexins was also induced by abiotic elicitation with CuCl2. Feeding both of L-[β-14C]tryptophan and L-[14CH3]methionine to UV-irradiated stem tuber tissue of kohlrabi indicated that the S-containing indole phytoalexins were biosynthesized from these amino acids.

scholarly journals Photochemistry of interstellar/circumstellar ices as a contributor to the complex organics in meteorites

2008 ◽  
Vol 4 (S251) ◽  
pp. 443-444
Author(s):  
Michel Nuevo ◽  
Scott A. Sandford
Keyword(s):  
Amino Acids ◽  
Organic Compounds ◽  
Uv Irradiation ◽  
Mechanisms Of Formation

AbstractThe UV irradiation of interstellar/circumstellar ice analogs is known to lead to the formation of organic compounds such as amino acids and maybe nucleobases. In this work, the mechanisms of formation and distribution of amino acids, chosen as tracers for the organic compounds formed in such experiments, are studied and compared with meteoritic data.

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