AUTHOR=Guo Yeting , Ying Jianxi , Sun Dongru , Zhang Yumeng , Zheng Minyang , Ding Ruiwen , Liu Yan , Zhao Yufen TITLE=Cyclic Dipeptides Formation From Linear Dipeptides Under Potentially Prebiotic Earth Conditions JOURNAL=Frontiers in Chemistry VOLUME=Volume 9 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.675821 DOI=10.3389/fchem.2021.675821 ISSN=2296-2646 ABSTRACT=Cyclic dipeptides (DKPs) are considered as peptide precursors and chiral catalysts in the prebiotic process. Here we report proline-containing DKPs spontaneously obtained from linear dipeptides under aqueous solution. Significantly, the yields of DKPs were affected by sequence of linear dipeptides and whether reaction contains trimetaphosphate. These findings provide the possibility that DKPs might play a key role in the origin of life.