Featured Article Prebiotic synthesis of sequential peptides on the Hadean beach by a molecular engine working with nitrogen oxides as energy sources

Addressing the still open question of the prebiotic origin of sequential macromolecules (peptides, nucleic acids) on the primitive Earth, we describe a molecular engine (the primary pump), which works at ambient temperature and continuously generates, elongates and complexifies sequen- tial peptides. This new scenario is based on a cyclic reaction sequence, whose keystep is the activation of amino acids into their N-carboxyanhydrides (NCA) through nitrosation by NOx. This process could have taken place on tidal beaches; it requires a buffered ocean, emerged land and a nitrosating atmosphere. With the help of geochemical studies and computer simulations of atmosphere photo- chemistry, we show that the primitive Earth during the Hadean may have satisfied all these require- ments. # 2001 Society of Chemical Industry.