Anthracene‐Walled Acyclic CB[n] Receptors: in vitro and in vivo Binding Properties toward Drugs of Abuse

We report studies of the interaction of six acyclic CB[n]‐type receptors toward a panel of drugs of abuse by a combination of isothermal titration calorimetry and 1H NMR spectroscopy. Anthracene walled acyclic CB[n] host (M3) displays highest binding affinity toward methamphetamine (Kd=15 nM) and fentanyl (Kd=4 nM). Host M3 is well tolerated by Hep G2 and HEK 293 cells up to 100 μM according to MTS metabolic and adenylate kinase release assays. An in vivo maximum tolerated dose study with Swiss Webster mice showed no adverse effects at the highest dose studied (44.7 mg kg−1). Host M3 is not mutagenic based on the Ames fluctuation test and does not inhibit the hERG ion channel. In vivo efficacy studies showed that pretreatment of mice with M3 significantly reduces the hyperlocomotion after treatment with methamphetamine, but M3 does not function similarly when administered 30 seconds after methamphetamine. Molecular safeguards: We measured the molecular recognition properties of six acyclic cucurbit[n]uril type receptors toward a panel of thirteen drugs of abuse. The anthracene‐walled M3 host was found to display high affinity (Kd=15 nM) toward methamphetamine in vitro and good biocompatibility according to in vitro and in vivo assays. Finally, in vivo pretreatment of mice with M3 can reduce behavioral changes (locomotion) induced by methamphetamine.