Abstract
CM carbonaceous chondrites are the possible supply of building blocks of life to the early Earth, recording prebiotic chemical reaction. Sugars, including ribose, a component of RNA, have been identified from chondrites. However, the impact of aqueous alteration on these sugars are unclear. In this study, sugars in the LON 94101 (CM2.2-2.3) were investigated and four pentoses, including ribose, and three hexoses were detected. The total pentose content was lower than that of the Murchison meteorite (CM2.5), which experienced less aqueous alteration. Additionally, the formose-type reaction, a plausible sugar-forming reaction in parent bodies, was conducted. The sugar composition of the long-term reaction products resembled that of the meteorite. These findings suggest that sugars formed through reactions in the early stages of aqueous alteration and that the composition of these sugars changed over time. This indicates that meteorites and cometary dust with lower degrees of aqueous alteration were likely the primary carriers of sugars to early Earth.
