Examinando por Autor "Requena Torres, Miguel Angel"

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Acceso Abierto
Discovery in space of ethanolamine, the simplest phospholipid head group
(National Academy of Sciences, 2021-06-01) Rivilla, V. M.; Jiménez Serra, I.; Martín Pintado, J.; Briones, C.; Rodríguez Almeida, L. F.; Rico Villas, F.; Tercero, B.; Zeng, S.; Colzi, L.; De Vicente, P.; Martín, S.; Requena Torres, Miguel Angel; European Commission (EC); Agencia Estatal de Investigación (AEI); Comunidad de Madrid; Rivilla, V. M. [0000-0002-2887-5859]; Tercero, B. [0000-0002-4782-5259]; Martín, S. [0000-0001-9281-2919]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Cell membranes are a key element of life because they keep the genetic material and metabolic machinery together. All present cell membranes are made of phospholipids, yet the nature of the first membranes and the origin of phospholipids are still under debate. We report here the presence of ethanolamine in space, NH2CH2CH2OH, which forms the hydrophilic head of the simplest and second-most-abundant phospholipid in membranes. The molecular column density of ethanolamine in interstellar space is N = (1.51 +/- 0.07) x 1013 cm-2, implying a molecular abundance with respect to H2 of (0.9 - 1.4) x 10-10. Previous studies reported its presence in meteoritic material, but they suggested that it is synthesized in the meteorite itself by decomposition of amino acids. However, we find that the proportion of the molecule with respect to water in the interstellar medium is similar to the one found in the meteorite (10-6). These results indicate that ethanolamine forms efficiently in space and, if delivered onto early Earth, could have contributed to the assembling and early evolution of primitive membranes.
Acceso Abierto
Propargylimine in the laboratory and in space: millimetre-wave spectroscopy and its first detection in the ISM
(EDP Sciences, 2020-08-20) Bizzocchi, L.; Prudenzano, D.; Rivilla, V. M.; Pietropolli Charmet, A.; Giuliano, B. M.; Caselli, P.; Martín Pintado, J.; Jiménez Serra, I.; Martín, S.; Requena Torres, M. A.; Rico Villas, F.; Guillemin, J. C.; Centre National D'Etudes Spatiales (CNES); European Research Council (ERC); Agencia Estatal de Investigación (AEI); Rico Villas, F. [0000-0002-5351-3497]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. Small imines containing up to three carbon atoms are present in the interstellar medium (ISM). As alkynyl compounds are abundant in this medium, propargylimine (2-propyn-1-imine, HC ≡C−CH =NH) thus represents a promising candidate for a new interstellar detection. Aims. The goal of the present work is to perform a comprehensive laboratory investigation of the rotational spectrum of propargylimine in its ground vibrational state in order to obtain a highly precise set of rest frequencies and to search for it in space. Methods. The rotational spectra of E and Z geometrical isomers of propargylimine have been recorded in the laboratory in the 83–500 GHz frequency interval. The measurements have been performed using a source-modulation millimetre-wave spectrometer equipped with a pyrolysis system for the production of unstable species. High-level ab initio calculations were performed to assist the analysis and to obtain reliable estimates for an extended set of spectroscopic quantities. We searched for propargylimine at 3 mm and 2 mm in the spectral survey of the quiescent giant molecular cloud G+0.693-0.027 located in the central molecular zone, close to the Galactic centre. Results. About 1000 rotational transitions have been recorded for the E- and Z-propargylimine, in the laboratory. These new data have enabled the determination of a very accurate set of spectroscopic parameters including rotational, quartic, and sextic centrifugal distortion constants. The improved spectral data allowed us to perform a successful search for this new imine in the G+0.693-0.027 molecular cloud. Eighteen lines of Z-propargylimine were detected at level >2.5σ, resulting in a column-density estimate of N = (0.24 ± 0.02) × 1014 cm−2. An upper limit was retrieved for the higher energy E isomer, which was not detected in the data. The fractional abundance (with respect to H2) derived for Z-propargylimine is 1.8 × 10−10. We discuss the possible formation routes by comparing the derived abundance with those measured in the source for possible chemical precursors.
Restringido
Thiols in the Interstellar Medium: First Detection of HC(O)SH and Confirmation of C2H5SH
(IOP Science Publishing, 2021-04-30) Rodríguez Almeida, L. F.; Jiménez Serra, I.; Rivilla, V. M.; Martín Pintado, J.; Zeng, S.; Tercero, B.; De Vicente, P.; Colzi, L.; Rico Villas, F.; Martín, S.; Requena Torres, Miguel Angel; Comunidad de Madrid; Agencia Estatal de Investigación (AEI); European Research Council (ERC); European Commission (EC); Rodríguez Almeida, L. F. [0000-0002-9785-703X]; Jiménez Serra, I. [0000-0003-4493-8714]; Rivilla, V. M. [0000-0002-2887-5859]; Martín Pintado, J. [0000-0003-4561-3508]; Tercero, B. [0000-0002-4782-5259]; Martín, S. [0000-0001-9281-2919]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The chemical compounds carrying the thiol group (-SH) have been considered essential in recent prebiotic studies regarding the polymerization of amino acids. We have searched for this kind of compound toward the Galactic Center quiescent cloud G+0.693–0.027. We report the first detection in the interstellar space of the trans-isomer of monothioformic acid (t-HC(O)SH) with an abundance of ~1 × 10−10. Additionally, we provide a solid confirmation of the gauche isomer of ethyl mercaptan (g-C2H5SH) with an abundance of ~3 × 10−10, and we also detect methyl mercaptan (CH3SH) with an abundance of ~5 × 10−9. Abundance ratios were calculated for the three SH-bearing species and their OH analogs, revealing similar trends between alcohols and thiols with increasing complexity. Possible chemical routes for the interstellar synthesis of t-HC(O)SH, CH3SH, and C2H5SH are discussed, as well as the relevance of these compounds in the synthesis of prebiotic proteins in the primitive Earth.