Russian Journal of Physical Chemistry, 6(1). Lupatov,

V. Strizhov, V. et al. (2006). Modeling of fusion reactions of the organic compounds in conditions of a primary atmosphere of the Earth. International symposium on molecular photonics. St. Petersburg, Russia. E-mail: aiva@geokhi.​ru Racemization in Photodimerization of Solid Alanine Induced by Vacuum Ultraviolet Irradiation: Chiral Problem in Chemical Evolution Yudai Izumi, Akiko Imazu, Aki Mimoto, Kazumichi Nakagawa Graduate School of Human Development and Environment, Kobe University, Japan L-rich IWP-2 amino acid was detected from Murchison meteorite (e.g. Cronin and Pizzarello, 1997). In chemical evolution from monomer to peptides induced by vacuum ultraviolet (VUV) light and/or X-ray, photoracemization of l-type amino acids is a serious problem. In this work, we examined photodimerization and photoracemization of solid this website l-alanine (Ala) in an

attempt to examine whether the chirality of l-Ala was preserved in chemical evolution. We irradiated VUV light (wavelength = 172 nm) buy AZD6738 onto l-Ala thin films at about 290 K in vacuum. After irradiation, all samples were dissolved with distilled water and analyzed by a high performance liquid chromatography (HPLC). Fig. 1 shows chromatograms of irradiated l-Ala film (curve (a)) and aqueous solution of marker molecules (curve (b)). The peak of d-Ala (around 17 min), d-alanyl-l-alanine (D-L, around 25 min), l-alanyl-l-alanine (L-L, around 38 min) and l-alanyl-d-alanine (L-D, around 41 min) were found in curve (a). Thus we can write the equation as “l-Ala + hν → L-L + L-D + D-L + d-Ala.” Amount of Gly and d-alanyl-d-alanine (D-D) was smaller than detection limit. Production of L-D, D-L and d-Ala suggests that the chirality of l-Ala was not preserved. In contrast, d-type amino acids were not found in the case of photolysis of l-Asp (wavelength = 146 nm) (Izumi et al., in print). Racemization is a critical problem in production of biomacromolecules (protein,

DNA, RNA etc.). Therefore it is necessary to carry out the similar experiments using other amino acids and/or other energy sources in order to Adenosine triphosphate examine the “chiral stability” of amino acids and so on. Cronin, J. R. and Pizzarello, S. (1997). Enantiomeric excesses in meteoritic amino acids. Science 275: 951–955 Izumi, Y., Matsui, T., Koketsu, T. and Nakagawa, K. (in print). Preservation of homochirality of aspartic acid films irradiated with 8.5 eV vacuum ultraviolet light. Radiation Physics and Chemistry. E-mail: izumi@radix.​h.​kobe-u.​ac.​jp The Diversity of the Original Prebiotic Soup: Re-analyzing the Original Miller–Urey Spark Discharge Experiments A. Johnson1, H.J. Cleaves2, J.L. Bada3, A. Lazcano4 1Interdisciplinary Biochemistry Program, Indiana University, Bloomington, IN 47405; 2Geophysical Laboratory, Carnegie Institution of Washington, Washington D.C.