The delivery of extraterrestrial organic molecules to Earth by meteorites may have been important for the origin and early evolution of life1. Indigenous amino acids have been found in meteorites2—over 70 in the Murchison meteorite alone3. Although it has been generally accepted that the meteoritic amino acids formed in liquid water4 on a parent body, the water in the Murchison meteorite is depleted in deuterium5 relative to the indigenous organic acids6,7. Moreover, the meteoritical evidence8 for an excess of laevo-rotatory amino acids is hard to understand in the context of liquid-water reactions on meteorite parent bodies. Here we report a laboratory demonstration that glycine, alanine and serine naturally form from ultraviolet photolysis of the analogues of icy interstellar grains. Such amino acids would naturally have a deuterium excess similar to that seen in interstellar molecular clouds, and the formation process could also result in enantiomeric excesses if the incident radiation is circularly polarized. These results suggest that at least some meteoritic amino acids are the result of interstellar photochemistry, rather than formation in liquid water on an early Solar System body.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Oró, J. Comets and the formation of biochemical compounds on the primitive Earth. Nature 190, 389–390 (1961).
Cronin, J. R. & Pizzarello, S. Amino acids in meteorites. Adv. Space Res. 3, 5–18 (1983).
Cronin, J. R. & Chang, S. in Chemistry of Life's Origins (NATO ASI) (eds Greenberg, J. M., Pirronello, V. & Mendoza-Gomez, C.) 209–258 (Kluwer, Dordrecht, 1993).
Peltzer, E. T., Bada, J. L., Schlesinger, G. & Miller, S. L. The chemical conditions on the parent body of the Murchison meteorite: Some conclusions based on amino, hydroxy nd dicarboxylic acids. Adv. Space. Res. 4, 69–74 (1984).
Robert, F. & Epstein, S. The concentration and isotopic composition of hydrogen, carbon and nitrogen in carbonaceous meteorites. Geochim. Cosmochim. Acta 46, 81–95 (1982).
Lerner, N. R. Influence of Murchison or Allende minerals on hydrogen-dueterium exchange of amino acids. Geochim. Cosmochim. Acta 59, 1623–1631 (1995).
Lerner, N. R. Influence of Allende minerals on deuterium retention of products of the Strecker synthesis. Geochim. Cosmochim. Acta 61, 4885–4893 (1997).
Cronin, J. R. & Pizzarello, S. Enantiomeric excesses in meteoritic amino acids. Science 275, 951–955 (1997).
Sandford, S. A. The inventory of interstellar materials available for the formation of the Solar System. Meteorit. Planet. Sci. 31, 449–476 (1996).
Gibb, E. L. et al. An inventory of interstellar ices toward the embedded protostar W33A. Astrophys. J. 536, 347–356 (2000).
Gerakines, P. A., Schutte, W. A. & Ehrenfreund, P. Ultraviolet processing of interstellar ice analogs. I. Pure ices. Astron. Astrophys. 312, 289–305 (1996).
Tegler, S. C. et al. Detection of the 2165 inverse centimeter (4.619 micron) XCN band in the spectrum of L1551 IRS 5. Astrophys. J. 411, 260–265 (1993).
Bernstein, M. P., Sandford, S. A., Allamandola, L. J., Chang, S. & Scharberg, M. A. Organic compounds produced by photolysis of realistic interstellar and cometary ice analogs containing methanol. Astrophys. J. 454, 327–344 (1995).
Kerridge, J. F. Formation and processing of organics in the early Solar System. Space Sci. Rev. 90, 275–288 (1999).
Teixeira, T. C., Devlin, J. P., Buch, V. & Emerson, J. P. Discovery of solid HDO in grain mantles. Astron. Astrophys. 347, L19–L22 (1999).
Turner, B. E. Deuterated molecules in translucent and dark clouds. Astrophys. J. Suppl. Ser. 136, 579–629 (2001).
Lacy, J. H., Faraji, H., Sandford, S. A. & Allamandola, L. J. Unravelling the 10 µm ‘Silicate’ feature of protostars: the detection of frozen interstellar ammonia. Astrophys. J. 501, L105–L109 (1998).
Chiar, J. E. et al. The composition and distribution of dust along the line of sight towards the Galactic center. Astrophys. J. 537, 749–762 (2000).
Allamandola, L. J., Sandford, S. A., Tielens, A. G. G. M. & Herbst, T. M. Spectroscopy of dense clouds in the C-H stretching region: methanol and “diamonds”. Astrophys. J. 399, 134–146 (1992).
Irvine, W. M. Spectroscopic evidence for interstellar ices in Comet Hyakutake. Nature 383, 418–420 (1996).
Allamandola, L. J., Sandford, S. A. & Valero, G. Photochemical and thermal evolution of interstellar/pre-cometary ice analogs. Icarus 76, 225–252 (1988).
Matthews, C. N. & Moser, R. E. Peptide synthesis from hydrogen cyanide and water. Nature 215, 1230–1234 (1967).
Ehrenfreund, P., Bernstein, M. P., Dworkin, J. P., Sandford, S. A. & Allamandola, L. J. The photostability of amino acids in space. Astrophys. J. 550, L95–L99 (2001).
Sorrell, W. H. Origin of amino acids and organic sugars in interstellar clouds. Astrophys. J. 555, L129–L132 (2001).
Rubenstein, E., Bonner, W. A., Brown, G. S. & Bailey, J. Polarized stellar light. Science 283, 1415 (1999).
Rubenstein, E., Bonner, W. A., Noyes, H. P. & Brown, G. S. Supernovae and life. Nature 306, 118 (1983).
Bonner, W. A. & Bean, B. D. Asymmetric photolysis with elliptically polarized light. Orig. Life Evol. Biosphere 30, 513–517 (2000).
Warneck, P. A microwave-powered hydrogen lamp for vacuum ultraviolet photochemical research. Appl. Opt. 1, 721–726 (1962).
Prasad, S. S. & Tarafdar, S. P. UV radiation field inside dense clouds—Its possible existence and chemical implications. Astrophys. J. 267, 603–609 (1983).
Zhao, M. & Bada, J. L. Determination of alpha-dialkylamino acids and their enantiomers in geological samples by high-performance liquid chromatography after derivatization with a chiral adduct of o-phthaldialdehyde. J. Chromatogr. A 690, 55–63 (1995).
This work was supported by NASA grants from the Origins of Solar Systems, Exobiology, and Astrobiology programmes, as well as the NASA Ames Director's Discretionary Fund. We thank A. Weber, D. Glavin, O. Botta, J. Chambers and K. Nelson for discussions. We also acknowledge technical support from R. Walker.
The authors declare that they have no competing financial interests
About this article
Cite this article
Bernstein, M., Dworkin, J., Sandford, S. et al. Racemic amino acids from the ultraviolet photolysis of interstellar ice analogues. Nature 416, 401–403 (2002) doi:10.1038/416401a
Structural rearrangement of the acrylonitrile (AN) cluster in the gas phase under VUV one-photon radiation explored by mass-selected infrared spectroscopy
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy (2020)
Evidence of Surface Catalytic Effect on Cosmic Dust Grain Analogs: The Ammonia and Carbon Dioxide Surface Reaction
The Astrophysical Journal (2019)
Journal of Molecular Modeling (2019)
Oxygen as an Electron Scavenger: Its Role in Electron-Induced Activation of Coadsorbed Methane Embedded in Amorphous Solid Water
The Journal of Physical Chemistry C (2019)
Selective incorporation of proteinaceous over nonproteinaceous cationic amino acids in model prebiotic oligomerization reactions
Proceedings of the National Academy of Sciences (2019)