Influence of minerals on aldose formation during hydrothermal processes in meteorite parent bodies

Abstract Various prebiotic organic compounds have been identified in meteorites. Understanding the origins of these compounds is essential to comprehending prebiotic chemistry in the early Solar System. Regarding sugar formation, the formose reaction—polymerization of formaldehyde under alkaline aqueous conditions—has been considered a plausible prebiotic process in the meteorite parent bodies. However, studies on the influence of minerals on this reaction are limited. In this study, we conducted hydrothermal experiments to examine the impact of three silicate minerals—olivine, antigorite (Mg-rich serpentine), and saponite—on the production of aldose sugars under geochemically plausible conditions in the meteorite parent bodies during aqueous alteration. The presence of these minerals enhanced aldose production, indicating promoting effects on the formose reaction. With the presence of ammonia in the initial solutions, the minerals enhanced aldose formation at 1 day of the heating experiments. However, the aldoses decreased at 3 and 7 days of the heating experiments. This is probably because ammonia promoted the formation of other compounds by consuming aldoses. These mineral–organic interactions may have played a significant role in the prebiotic chemical evolution in meteorite parent bodies, possibly contributing to the inventory of organic compounds delivered to early Earth.