pyrimidine metabolic pathway pyrimidine biosynthetic pathway 2011-06-03T03:33:51Z PW:0000861 Pyrimidine biosynthesis Those enzymatic reactions involved in the synthesis of pyrimidine nucleotides. A major route for pyrimidine synthesis is the de novo pathway. However, an alternate pathway, the salvage pathway, converts nucleosides generated by DNA or RNA breakdown back to nucleotide monophosphates which can then re-enter the biosynthetic pathway. pathway pyrimidine nucleobase biosynthetic process vpetri