title: Discovery of a novel tetrahydroacridine acetylcholinesterase inhibitor through an indexed combinatorial library.
abstract: BACKGROUND
  Methods for the rapid and efficient preparation of drug candidates through combinatorial chemistry are of increasing interest. We have previously reported an indexed combinatorial library method that allows both the preparation and testing of compounds in solution. We set out to apply this method to develop more effective analogs of the known, marketed drug tacrine, an acetylcholinesterase inhibitor.
  
  
  RESULTS
  A one-step condensation of cyclohexanones with cyanoanilines to generate tetrahydroacridine pools was developed. The resulting library of (formally) 72 tetrahydroacridines was screened against acetylcholinesterase, and a compound 10-fold more potent than tacrine, 7-nitrotacrine, was discovered. Its increased potency could be readily explained by examining the known structure of the complex of acetylcholinesterase with tetrahydroacridine.
  
  
  CONCLUSIONS
  In this work, we have provided a relatively rare example of carbon-carbon bond formation in a pool synthesis and have discovered a potentially useful acetylcholinesterase inhibitor.
authors.affiliation: Department of Chemistry, Duke University, Durham, NC 27708-0346, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Pirrung
authors.forename: J H
authors.initials: JH
authors.lastname: Chau
authors.forename: J
authors.initials: J
authors.lastname: Chen
mesh_terms: D000166:Acridines / Q000138:chemical synthesis* / Q000737:chemistry; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry; D004593:Electrophorus; D007700:Kinetics; D013056:Spectrophotometry, Ultraviolet; D013619:Tacrine / Q000737:chemistry
chemical_list: D000166:Acridines; D002800:Cholinesterase Inhibitors; D013619:Tacrine