[BAO01-P07] Influence of existing water ice for pressure-induced formation of alanine oligopeptides at 25 °C
Keywords:Amino acid, High pressure, water ice
All high-pressure experiments were carried out at 25 °C. Starting material was loaded in a high-pressure cell with two different conditions: solid and solution (solid: L-alanine powder. solution: saturated L-alanine aqueous solution.). The samples were compressed using an opposed-anvil apparatus (non-toroidal phi8-5 sintered diamond anvil). The sample volumes were approximately 24 mm3. The experiments were conducted at pressure of approximately 11 GPa. After decompression to ambient pressure, the samples were dissolved in pure water and analyzed using LC-MS.
Alanine dimer was detected from both run products (solid and solution). It is noteworthy that oligomerization of alanine occurred under solid and solution condition. In the pressure and temperature conditions applied in this study, water in the samples existed as ice VII, a high-pressure phase of water, in other words, the oligomerization observed here was a solid-phase reaction. Also, solid condition provided solid-phase reaction. In the presentation, we will discuss the difference of peptides yields between solid and solution.This study confirmed that oligomerization of amino acids occurs under high pressure at room temperature with existence of water as ice VII which is known to exist in the interiors of icy bodies. This study proposed that interiors of icy bodies can be new abiotic conditions for oligomerization of amino acids.