2005 年 33 巻 4 号 p. 269-274
There have been several studies on biopolymer synthesis under hydrothermal conditions. Although dimer and short oligomers were obtained from a monomer unit, few of longer oligomers were obtained. These studies that were applied with various quenching methods suggested the importance of quenching speed from hydrothermal conditions. We hypothesized a rapid quenching could avoid hydrolysis of the oligomers that had already been synthesized under hydrothermal conditions. We designed a novel hydrothermal flow reactor with adiabatic expansion cooling, which was thought to be one of the most rapid quenching methods. This system simulates geysers, fumaroles, hot springs and volcanic eruptions. After aqueous solutions of monomers were treated at high temperature and pressure, they were released into the atmosphere through an orifice to be depressurized and cooled down simultaneously with the Joule-Thomson effect. Using the flow reactor, we have demonstrated oligomerization of glycine up to decamer (Gly10), which had never been yielded with any other quenching methods. This suggests that rapid quenching methods under non-equilibrium conditions such as adiabatic expansion cooling is an efficient way to produce long oligomers connected by covalent bonds via dehydration condensation.
