Abiotic sugars in (162173) Ryugu and the primitive CI carbonaceous chondrite Orgueil

The unequal distribution of prebiotic organic compounds in meteorites—where amino acids and nucleobases are commonly detected but sugars remain scarce and poorly characterized—poses a major challenge in our understanding of extraterrestrial organic chemistry. This disparity is particularly surprising given the robust formation of sugars in laboratory simulations of interstellar ice chemistry, suggesting their plausible synthesis under space conditions. Here we present a novel analytical workflow combining ultrasonic-assisted extraction with enantioselective comprehensive two-dimensional gas chromatography, enabling simultaneous analysis of sugars and amino acids in samples from the asteroid (162173) Ryugu and the Orgueil meteorite. We report the detection of multiple aldoses—including ribose, arabinose, lyxose, and the formose reaction intermediate ribulose—some of which exhibited racemic distributions consistent with an abiotic, extraterrestrial origin. Meteorite recovery experiments revealed that native sugar abundances, including ribose, are drastically underestimated, with recoveries often below 5%. Despite this, pentose abundances were comparable to those of C₄–C₅ amino acid enantiomers, suggesting that actual sugar concentrations are likely higher. These findings provide compelling evidence for efficient abiotic sugar synthesis in space and support the idea that meteorites may have delivered a broader suite of prebiotically relevant sugars to early Earth than previously recognized strengthening the potential link between extraterrestrial chemistry and the origins of life.