Abiotic Sugar Enantiomers In The CI Carbonaceous Chondrite Orgueil

The uneven detection of prebiotic organic compounds in meteorites—where amino acids and nucleobases are commonly identified but sugars remain rare and poorly characterized—limits our understanding of extraterrestrial organic chemistry.

This discrepancy is striking given that laboratory simulations of interstellar ice chemistry readily produce complex sugars. Here we report the simultaneous analysis of sugar and amino acid enantiomers in a meteorite sample.

Multiple aldoses were detected in the Orgueil meteorite, including ribose, arabinose, xylose, lyxose, and the ketopentose ribulose, several of which display near-racemic distributions consistent with an extraterrestrial origin. Recovery experiments demonstrate that sugar abundances are severely underestimated.

Despite this limitation, pentose abundances are comparable to those of some C4–C5 amino acid enantiomers, implying higher true concentrations. These results indicate efficient abiotic sugar formation in space and suggest that meteorites may have delivered a broader range of prebiotically relevant sugars to early Earth than previously recognized.

Astrobiology, Astrochemistry,