We recorded the CD spectra of several amino acids, among them proteinogenic as well as non-proteinogenic α-H and α-methyl amino acids and diamino acids in different liquid solvents (Bredehöft et al. 2007) and in the solid phase. Based on these spectra and quantum mechanical calculations, a model will be presented that illustrates the nature of the electronic excitation that is involved in the asymmetric photolysis of amino acids. This shows that indeed a single kind of photochemical

reaction is sufficient to account for the asymmetric photolysis of most amino acids. Furthermore, the differences between spectra recorded under various conditions and the impact on asymmetric MK-8776 clinical trial photochemistry that these conditions have will be discussed. Bailey, J., Chrysostomou,

A., Hough, J. H., Gledhill, T. M., McCall, A., Clark, S., Ménard, F., and MEK162 chemical structure Tamura, M., (1998). Circular Polarization in Star-Formation Regions: Implications for Biomolecular Homochirality, Science 281:672–674. Bredehöft, J. H., Breme, K., Meierhenrich, U. J., Hoffmann, S. V., Thiemann, W. H.-P. (2007). Chiroptical Properties of Diamino Carboxylic Acids, Chirality, 19:570–573. Bredehöft, J. H. and Meierhenrich, U. J. (in press), Amino acid structures from UV irradiation of simulated interstellar ices, in Takenaka, ioxilan N. (Ed), Recent Developments in (Photo-)Chemistry in Ice, Research Signpost, Kerala, India. Buschermöhle, M., Whittet, D. C. B., Chrysostomou, A., Hough, J. H., Lucas, P.W., Adamson, A. J., Whitney, B. A. and Wolff, M. J. (2005). An Extended Search for Circularly Polarized Infrared Radiation from the OMC-1 Region of Orion, Astrophys J, 624:821–826. Lucas, P.W., Hough, J. H., Bailey, J., Chrysostomou, A., Gledhill, T. M., McCall, A. (2005). UV Circular Polarisation in Star Formation Regions: The Origin of Homochirality?,

Orig. Life Evol. Biosph. 35:29–60. Meierhenrich, U. J., Nahon, L., Alcaraz, C., Bredehöft, J. H., Hoffmann, S. V., Barbier, B., Brack, A. (2005). Asymmetric vacuum UV photolysis of the amino acid leucine in the solid state, Angew. Chem. Int. Ed., 44:5630–5634. Pizzarello, S., Cronin, J. R., (2000). Non-racemic amino acids in the Murray and Murchison meteorites, Geochem. Cosmochem. Acta, 64(2):329–338 E-mail: j.​h.​bredehoft@open.​ac.​uk A Possible Astrophysical Pathway to the Origin of Enantiomeric Excess in Primitive Meteorites: Laboratory selleck Simulations P. de Marcellus1, G. Danger1, L. Nahon2, U. Meierhenrich3, L.d’Hendecourt1 1Astrochimie et Origines, Institut d’Astrophysique Spatiale, Orsay, France; 2Synchrotron SOLEIL, L’Orme des Merisiers—BP 48, 91190 Saint-Aubin, France; 3Laboratoire A.S.I.