. "The chemical reactions and pathways resulting in the formation of adenine, 6-aminopurine, one of the five main bases found in nucleic acids and a component of numerous important derivatives of its corresponding ribonucleoside, adenosine." . . . "adenine biosynthetic process" . "adenine anabolism" . "adenine biosynthesis" . "adenine formation" . "adenine synthesis" . . . .