Guanylic acid (5'-GMP) is a purine nucleotide that participates in physiological processes such as energy metabolism, signal transduction, and gene expression regulation. Guanylic acid (5'-GMP) regulates the expression of genes related to fatty acid metabolism. Guanylic acid (5'-GMP) is the weak agonist for ionotropic glutamate receptors (iGluR), reduces the activity of the glutamatergic system and exhibits neuroprotective effect. Guanylic acid (5'-GMP) also causes neuronal cell death at high concentrations.