2008 年 42 巻 1 号 p. 23-40
In this review article, stereo chemical investigation of biogenic and abiogenic organic compounds regarding organic cosmochemical and geochemical approaches were summarized. Representative results are as follows. At first, endo- and exogenous abiotic formation of bio-organic compounds were experimentally verified. Among these, high-molecular-weight complex organics synthesized from mixtures of simple inorganic gases similar to those found in the interstellar medium were irradiated with a particle beam. Molecular weight of complex organics were ranging from several hundred to 3,000 Da. A wide variety of organic compounds, not only a number of amide compounds, but also heterocyclic and polycyclic aromatic hydrocarbons (PAHs), were detected by Curie point pyrolysis combined with gas chromatograph and mass spectrometer (Pyr/GC/MS). Secondary, emergence of enantiomeric excess of chiral amino acids in meteorite were experimentally verified. Before acid-hydrolysis, the synthesized high-molecular-weight complex organics containing amino acid precursors were irradiated with right (R-) or left (L-) continuous ultraviolet circularly polarized light (UV-CPL) obtained from a synchrotron radiation (SR). Enantiomeric excesses (% D-% L) were obtained by UV-R-CPL and UV-L-CPL, respectively: R-CPL preferentially produced D-alanine, and L-CPL yielded more L-alanine. Thirdly, the author described molecular chirality in extreme environment and sub-surface biosphere. Deep-sea hydrothermal systems are natural laboratories for the study of organic geochemistry related to molecular chirality and microbial habitats on extreme environments. A high-temperature deep-sea hydrothermal system was drilled using the benthic multi-coring system (BMS) employed for direct sampling of microorganisms, rocks and fluids beneath hydrothermal vents as a part of the Archaean Park Project (International research project on interaction between sub-vent biosphere and geo-environment). Based on the distribution of organic compounds derived from this vigorous hydrothermal environment, a description of deep-sea subterranean chemistry and biology was investigated with optimal microbial activities.