Synthesis and anticholinesterase activity of (-)-N1-norphysostigmine, (-)-eseramine, and other N(1)-substituted analogues of (-)-physostigmine

J Med Chem. 1988 Dec;31(12):2297-300. doi: 10.1021/jm00120a008.

Abstract

(-)-N1-Benzylnorphysostigmine (4), prepared from synthetic (-)-O-methyl-N1-noreseroline (1) by N-benzylation, ether cleavage, and reaction of (-)-N1-benzylnoreseroline (3) with methyl isocyanate, was the intermediate used to prepare the title compounds. Catalytic debenzylation of 4 afforded (-)-N1-norphysostigmine (5), and (-)-eseramine (6) was obtained by reaction of 5 with methyl isocyanate. Reductive N-methylation of 5 gave (-)-physostigmine (9) while reaction of 5 with allyl bromide and phenethyl bromide afforded carbamates 7 and 8, respectively. Data on the in vitro potencies (IC50) and activities of certain of these compounds (4-8) as inhibitors of electric eel acetyl cholinesterase are reported. (-)-N1-Norphysostigmine (5) was found to be similarly potent against AChE as (-)-physostigmine (9).

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Cholinesterase Inhibitors / chemical synthesis*
  • Cholinesterase Inhibitors / pharmacology
  • Electrophorus
  • Methylation
  • Physostigmine / analogs & derivatives*

Substances

  • Cholinesterase Inhibitors
  • Physostigmine