Hypoxanthine is a naturally occurring purine derivative. It is occasionally found as a constituent of nucleic acids where it is present in the anticodon of tRNA in the form of its nucleoside inosine. It is also known as 6-Hydroxypurine. Hypoxanthine is a necessary additive in certain cell, bacteria and parasite cultures as a substrate and nitrogen source. For example it is commonly a required reagent in malaria parasite cultures since Plasmodium falciparum requires a source of hypoxanthine for nucleic acid synthesis and energy metabolism.
Hypoxanthine is also a spontaneous deamination product of adenine. Because of its resemblance to guanine, the spontaneous deamination of adenine can lead to an error in DNA transcription/replication.
Additional images
Adenine. Notice the extra nitrogen compared to the oxygen in hypoxanthine. (Disregard the fact that the rings are in opposite positions.)
