“…4) The guanidine derivatives exhibited diverse biological and pharmacological activities such as neuronal Na + and Ca 2+ channel blockers, 5) glutamate release inhibitors, anti-ischemic agents, 6) anti-seizure agents, 7) aderenergic neuron-blocking agents, 8) human immunodeficiency virus-1 (HIV-1) protease inhibitors, 9) K + /ATP channel openers, nitric oxide (NO) synthase inhibitors, influenza neuraminidase inhibitors, 10) cardiotonic agents, 11) and histamine H 3 receptor antagonists. 12) Therefore, the guanidine functional group is an attractive pharmacophore for the development of novel drugs against tumors, hypertension, glaucoma, and inflammation. 13) We previously reported that phosphorylation of various drugs improves their biological activity.…”