Abiotic synthesis of guanine with high-temperature plasma.

The origin of guanine has been unknown, though there are some reports concerning its abiotic synthesis. We show here that guanine, as well as uracil and cytosine, are synthesized from a 90%N2-10%CO-H2O gas mixture via a complex organic product produced with the high-temperature and rapid quenching technique. This result implies that a large amount of complex organic matter including precursors of bioorganic compounds might have been produced on the primitive earth after cometary impacts.