purine biosynthetic pathway de novo purine biosynthetic pathway 2011-06-06T04:50:02Z De novo purine biosynthesis requires ten enzymatic reactions to produce inosine monophosphate (IMP). Both adenine and guanine are then derived from IMP via several reactions. Purines are synthesized as nucleosides, i.e., as bases attached to ribose. Purines can also be created synthetically. PW:0000867 pathway vpetri