A deoxyadenosyl radical is a free radical that is structurally related to adenosine by removal of a 5′-hydroxy group from adenosine.

This radical occurs in nature as a reactive intermediate.

It is generated by radical SAM enzymes and by some varieties of vitamin B12.

[1] The deoxyadenosyl radical abstracts hydrogen atoms from substrates, causing rearrangements and other post transcriptional modifications required for biosynthesis.

[2]