ATP 
GMP 
N-formyl-N-hydroxy-aminoacetate,
AMP, GMP, GDP
6-diazo-5-oxo-L-nor-leucine,
AMP, L-azaserine
IMP to AMP and GMP conversion
AMP,
ADP, ATP, GMP, GDP, IMP, 6-diazo-5-oxo-L-nor-leucine, azaserine
L-azaserine,
6-diazo-5-oxo-L-norleucine
AMP,
GMP 
AMP,
GMP 
AMP,
GMP 
IMP synthesis: the purine nucleotides precursor
ADP,
GDP, trypotophan
PRPP (Phosphoribosyl
Pyrophosphate)
PRPP synthesis:
De novo synthesis of PURINE RIBOnucleotides
GTP
+