Original: Apart from the Miller-Urey experiment, described above, the next most important step in research on prebiotic organic synthesis was the demonstration by John Oró that the nucleic acid purine base, adenine, was formed by heating aqueous ammonium cyanide solutions.
Simplified: The next most important step in research on prebiotic organic synthesis was the demonstration by John Oró that the nucleic acid purine base, adenine, was formed by the simple heating of solutions of ammonium cyanide.