Investigation of biomolecules produced by oceanic impacts of meteorites

生物前地球上的生物分子的形成还不清楚。生物分子的来源有三种：地外输运、热液喷口形成和撞击反应形成。热液喷口的陆外运移和形成已被广泛研究。最近，我们发现通过撞击反应生成了氨基酸、胺和羧酸。然而，到目前为止，关于撞击反应生成挥发性有机化合物的研究还很少。在本研究中，我们主要关注可能由撞击反应生成的挥发性有机化合物(VOC)。我们制作了一种VOC收集器来回收碰撞实验容器中产生的VOCs。用GC/MS对VOCs进行了分析，发现有烃类、醇类、醛类和腈类化合物的形成。根据模拟某些类型球粒陨石的原料组成的不同，这些产率也不同。当原料中含有黄铁矿时，生成含硫有机物，而当原料中含有硫铁矿而不含黄铁矿时，则不会生成含硫有机物。这些结果表明，包括含硫VOCs在内的各种VOCs是由益生菌影响产生的。

Formation of biomolecules on the prebiotic Earth has not been clear. There are three kinds of proposed origins of the biomolecules : extraterrestrial delivery, formation in hydrothermal vent, and formation by impact reactions. The extraterrestrial delivery and the formation in hydrothermal vent have been investigated intensively. Recently, we found the formation of an amino acid, amines, and carboxylic acids by impact reactions. However, little investigations have been conducted about the formation by impact reaction so far.In this study, we focused on volatile organic compounds (VOC)that may be formed by impact reactions. We made a VOC collector to recover produced VOCs from container of impact experiments. The VOCs were analyzed by GC/MS. We found the formation of hydrocarbons, alcohols, an aldehyde, and a nitrile. Those yields were different according to the difference in the compositions of starting materials that simulating some types of chondrites. The formation of sulfur containing organic compound was occurred when the starting material contained pyrite, but was not occurred when they contained troilite instead of pyrite. These results suggest that various VOCs including sulfur containing VOCs were produced by prebiotic impacts.