Structural formula of inosine. Inosine is a nucleoside containing hypoxanthine and ribose. It differs from adenosine by the absence of an amino group at the 6 position of the purine ring. (Image: ...

The paper S.C. Kim et al., “Inosine, but none of the 8-oxo-purines, is a plausible component of a primordial version of RNA,” PNAS, 115:13318–23, 2018. Proponents of the RNA world theory argue that ...