Precursors of fatty alcohols in the ISM: Discovery of n-propanol

Abstract

Theories on the origins of life propose that early cell membranes were synthesized from amphiphilic molecules simpler than phospholipids such as fatty alcohols. The discovery in the interstellar medium (ISM) of ethanolamine, the simplest phospholipid head group, raises the question whether simple amphiphilic molecules are also synthesized in space. We investigate whether precursors of fatty alcohols are present in the ISM. For this, we have carried out a spectral survey at 7, 3, 2 and 1 mm toward the Giant Molecular Cloud G+0.693-0.027 located in the Galactic Center using the IRAM 30m and Yebes 40m telescopes. Here, we report the detection in the ISM of the primary alcohol n-propanol (in both conformers Ga-n-C3H7OH and Aa-n-C3H7OH), a precursor of fatty alcohols. The derived column densities of n-propanol are (5.5+-0.4)x10^13 cm^-2 for the Ga conformer and (3.4+-0.3)x10^13 cm^-2 for the Aa conformer, which imply molecular abundances of (4.1+-0.3)x10^-10 for Ga-n-C3H7OH and of (2.5+-0.2)x10^-10 for Aa-n-C3H7OH. We also searched for the AGa conformer of n-butanol (AGa-n-C4H9OH) without success yielding an upper limit to its abundance of <4.1x10^-11. The inferred CH3OH:C2H5OH:C3H7OH:C4H9OH abundance ratios go as 1:0.04:0.006:<0.0004 toward G+0.693-0.027, i.e. they decrease roughly by one order of magnitude for increasing complexity. We also report the detection of both syn and anti conformers of vinyl alcohol, with column densities of (1.11+-0.08)x10^14 cm^-2 and (1.3+-0.4)x10^13 cm^-2, and abundances of (8.2+-0.6)x10^-10 and (9.6+-3.0)x10^-11, respectively. The detection of n-propanol, together with the recent discovery of ethanolamine in the ISM, opens the possibility that precursors of lipids according to theories of the origin of life, could have been brought to Earth from outer space.

15 pages, 10 figures, accepted for A&A

References in corpus (22)

• Astrochemistry During the Formation of Stars
• The largest oxigen bearing organic molecule repository
• Parametrization of C-shocks. Evolution of the Sputtering of Grains
• Tracing shocks and photodissociation in the Galactic center region
• Yebes 40 m radio telescope and the broad band NANOCOSMOS receivers at 7 mm and 3 mm for line surveys
• Thiols in the ISM: first detection of HC(O)SH and confirmation of C${}_2$H${}_5$SH
• Prebiotic precursors of the primordial RNA world in space: Detection of NH${}_2$OH
• Cloud-cloud collision as drivers of the chemical complexity in Galactic Centre molecular clouds
• ALCHEMI: an ALMA Comprehensive High-resolution Extragalactic Molecular Inventory. Survey presentation and first results from the ACA array
• O-bearing complex organic molecules at the cyanopolyyne peak of TMC-1: detection of C2H3CHO, C2H3OH, HCOOCH3, and CH3OCH3
• Infrared H3+ and CO Studies of the Galactic Core: GCIRS 3 and GCIRS 1W
• The ALMA-PILS survey: First detection of the unsaturated 3-carbon molecules Propenal (C${}_2$H${}_3$CHO) and Propylene (C${}_3$H${}_6$) towards IRAS 16293$-$2422 B
• First detection of C${}_2$H${}_5$NCO in the ISM and search of other isocyanates towards the G+0.693-0.027 molecular cloud
• Formation of complex molecules in translucent clouds: Acetaldehyde, vinyl alcohol, ketene, and ethanol via nonenergetic processing of C2H2 ice
• Detection of the cyanomidyl radical (HNCN): a new interstellar species with the NCN backbone
• Formation of interstellar propanal and 1-propanol ice: a pathway involving solid-state CO hydrogenation
• The trans/cis ratio of formic, HCOOH, and thioformic, HC(O)SH, acids in the Interstellar Medium
• The origin of the E/Z isomer ratio of imines in the interstellar medium
• Submillimeter spectroscopy and astronomical searches of vinyl mercaptan, C${}_2$H${}_3$SH
• Alcohols on the rocks: solid-state formation in a H3CCCH + OH cocktail under dark cloud conditions
• Ionise hard: interstellar PO${}^{+}$ detection
• Non-Energetic Formation of Ethanol via CCH Reaction with Interstellar H2O Ices. A Computational Chemistry Study

Cited by in corpus (23)

• Discovery of the elusive carbonic acid (HOCOOH) in space
• First detection in space of the high-energy isomer of cyanomethanimine: H2CNCN
• Amides inventory towards the G+0.693-0.027 molecular cloud
• On the abiotic origin of dimethyl sulfide: discovery of DMS in the Interstellar Medium
• Discovery of thionylimide, HNSO, in space: the first N-, S- and O-bearing interstellar molecule
• The first detection of SiC${}_2$ in the interstellar medium
• Shocking Sgr B2(N1) with its own outflow: A new perspective on segregation between O- and N-bearing molecules
• A deep search for large complex organic species toward IRAS16293-2422 B at 3 mm with ALMA
• Reexploring Molecular Complexity with ALMA: Insights into chemical differentiation from the molecular composition of hot cores in Sgr B2(N2)
• Conformational isomerism of methyl formate: new detections of the higher-energy trans conformer and theoretical insights
• Millimetre and submillimetre spectroscopy of isobutene and its detection in the molecular cloud G+0.693
• CoCCoA: Complex Chemistry in hot Cores with ALMA. The chemical evolution of acetone from ice to gas
• H2CN/H2NC abundance ratio: a new potential temperature tracer for the interstellar medium
• Rotation-tunneling spectrum and astrochemical modeling of dimethylamine, CH${}_3$NHCH${}_3$, and searches for it in space
• The salty emission of the intermediate-mass AGB star OH 30.1 -0.7
• Advancing spectroscopic understanding of HOCS${}^{+}$: Laboratory investigations and astronomical implications
• A detection of sulfur-bearing cyclic hydrocarbons in space
• The GUAPOS project. VI: the chemical inventory of shocked gas
• A high-resolution spectroscopic analysis of aminoacrylonitrile and an interstellar search towards G+0.693
• Chemical templates of the Central Molecular Zone. Shock and protostellar object signatures under Galactic Center conditions
• Expanding the C${}_3$H${}_6$O${}_2$ Isomeric Interstellar Inventory: Discovery of Lactaldehyde and Methoxyacetaldehyde in G+0.693-0.027
• Chemistry of Dark Molecular Clouds
• Synthesis and Spectroscopic Characterization of Interstellar Candidate Ethynyl Thiocyanate: HCCSCN