The Sulfonadyns: a Class of Aryl Sulfonamides Inhibiting Dynamin I GTPase and Clathrin Mediated Endocytosis Are Anti-seizure in Animal Models

We show that dansylcadaverine (1) a known in-cell inhibitor of clathrin mediated endocytosis (CME), moderately inhibits dynamin I (dynI) GTPase activity (IC 45 μM) and transferrin (Tfn) endocytosis in U2OS cells (IC 205 μM). Synthesis gave a new class of GTP-competitive dynamin inhibitors, the Sulfonadyns™. The introduction of a terminal cinnamyl moiety greatly enhanced dynI inhibition. Rigid diamine or amide links between the dansyl and cinnamyl moieties were detrimental to dynI inhibition. Compounds with inhibition of dynI activity <10 μM were tested in-cell for inhibition of CME. These data unveiled a number of compounds, analogues 33 (()--(6-{[(3-(4-bromophenyl)-2-propen-1-yl]amino}hexyl)-5-isoquinolinesulfonamide)) and 47 (()--(3-{[3-(4-bromophenyl)-2-propen-1-yl]amino}propyl)-1-naphthalenesulfonamide)isomers that showed dyn IC <4 μM, IC <30 μM and IC from 12-265 μM. Both analogues (33 and 47) are at least 10 times more potent that the initial lead, dansylcadaverine (1). Enzyme kinetics revealed these sulfonamide analogues as being GTP competitive inhibitors of dynI. Sulfonadyn-47, the most potent SVE inhibitor observed (IC = 12.3 μM), significantly increased seizure threshold in a 6 Hz mouse psychomotor seizure test at 30 ( = 0.003) and 100 mg kg ip ( < 0.0001), with similar anti-seizure efficacy to the established anti-seizure medication, sodium valproate (400 mg kg). The Sulfonadyn™ class of drugs target dynamin and show promise as novel leads for future anti-seizure medications.