Pentoses are essential carbohydrates in the metabolism of modern lifeforms, but their availability during early Earth is unclear since these molecules are unstable. A new study led by the Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology, Japan, reveals a chemical pathway compatible with early Earth conditions and by which C6 aldonates could have acted as a source of pentoses without the need for enzymes. Their findings provide clues about primitive biochemistry and bring us closer to understanding the Origins of Life. Charles Liotta, Regents' Professor Emeritus in the School of Chemistry and Biochemistry with a joint appointment in the School of Chemical and Biomolecular Engineering, is a co-author of the study.