Anionic cyclophanes as potential reversal agents of muscle relaxants by chemical chelation

A series of carboxyl-containing cyclophanes have been designed and synthesised as chemical chelators (or host molecules) of cationic muscle relaxant drugs (or guest molecules). Three of these cyclophane derivatives, 1-3, have been shown by NMR to form 1:1 complexes with the muscle relaxants pancuronium. 4 and gallamine, 5 in D2O, with association constants up to 10(4) M-1. When tested in an in vitro chick biventer muscle preparation, the cyclophanes reversed the neuromuscular block induced by pancuronium and gallamine, with 3 having the most effective reversal against pancuronium (EC50 40 muM). (C) 2002 Elsevier Science Ltd. All rights reserved.