TRIAL OF PORPHYRIN SYNTHESIS ON SAPONITE SURFACE AS A GENETIC MODEL FROM CLAY MINERAL TO ORGANIC MOLECULES

抄録

To propose a simple and primitive genetic model before appearance of the current gene such as RNA and DNA, we investigated the information transfer between clay minerals, which have existed since ancient times, and organic molecules. A porphyrin synthesis was attempted in clay dispersion, expecting that the cationic porphyrin synthesis would be promoted on the surface of the anionic clay minerals due to the similarity of their average charge sequences. In the control experiment in water without clay, it was found that there were optimum values for concentration and pH conditions, and the estimated yield was about 20% at maximum. However, in clay dispersion, the estimated yield was 2%. This result suggests that the substrate enrichment effect on the clay surface of the electrostatic field had a pronounced influence, and the expected enhancement of porphyrin formation based on charge sequence similarity could not be confirmed. However, the suppression of intramolecular motions due to the electrostatic interactions between the reaction intermediates and the clay surface was observed, indicating that the clay surface has a specific effect on organic reactions that is different from that in solution. In other word, the reactions that make the linear multimer were accelerated and the cyclization that produces the porphyrinogen was suppressed by the effect of the surface.