4,9-Anhydrotetrodotoxin (4,9-anhydro-TTX) is a derivative of TTX that selectively blocks inward sodium current through Nav1.6 voltage-activated sodium channels (IC50 = 7.8 nM in Xenopus oocytes). It demonstrates IC50 values of 1.3, 0.34, 0.99, 78.5, 1.3, and >30 μM for Nav1.2, Nav1.3, Nav1.4, Nav1.5, Nav1.7, and Nav1.8, respectively.
[1] CHRISTIAN ROSKER. The TTX metabolite 4,9-anhydro-TTX is a highly specific blocker of the Na(v1.6) voltage-dependent sodium channel.[J]. American journal of physiology. Cell physiology, 2007, 293 2: C783-9. DOI:
10.1152/ajpcell.00070.2007[2] NICHOLAS DENOMME . The voltage-gated sodium channel inhibitor, 4,9-anhydrotetrodotoxin, blocks human Nav1.1 in addition to Nav1.6[J]. Neuroscience Letters, 2020, 724: Article 134853. DOI:
10.1016/j.neulet.2020.134853
