Synthesis, antimalarial activity, and molecular modeling of new pyrrolo[1,2-a]quinoxalines, bispyrrolo[1,2-a]quinoxalines, bispyrido[3,2-e]pyrrolo[1,2-a]pyrazines, and bispyrrolo[1,2-a]thieno[3,2-e]pyrazines

J Med Chem. 2004 Apr 8;47(8):1997-2009. doi: 10.1021/jm0310840.

Abstract

Three pyrrolo[1,2-a]quinoxalines, 15 bispyrrolo[1,2-a]quinoxalines, bispyrido[3,2-e]pyrrolo[1,2-a]pyrazines, and bispyrrolo[1,2-a]thieno[3,2-e]pyrazines were synthesized from various substituted nitroanilines or nitropyridines and tested for their in vitro activity upon the erythrocytic development of Plasmodium falciparum strains with different chloroquine-resistance status. Bispyrrolo[1,2-a]quinoxalines showed superior antimalarial activity with respect to monopyrrolo[1,2-a]quinoxalines. The best activity was observed with bispyrrolo[1,2-a]quinoxalines linked by a bis(3-aminopropyl)piperazine. Moreover, it was observed that the presence of a methoxy group on the pyrrolo[1,2-a]quinoxaline nucleus increased the pharmacological activity. Drug effects upon beta-hematin formation were assayed and showed similar or higher inhibitory activities than CQ. A possible mechanism of interaction implicating binding of pyrroloquinoxalines to beta-hematin was supported by molecular modeling.

MeSH terms

  • Animals
  • Antimalarials / chemical synthesis*
  • Antimalarials / chemistry
  • Antimalarials / pharmacology
  • Cell Line
  • Crystallography, X-Ray
  • Drug Resistance
  • Erythrocytes / parasitology
  • Hemeproteins / chemistry
  • Humans
  • In Vitro Techniques
  • Models, Molecular
  • Plasmodium falciparum / drug effects
  • Protein Binding
  • Pyrazines / chemical synthesis*
  • Pyrazines / chemistry
  • Pyrazines / pharmacology
  • Pyridines / chemical synthesis*
  • Pyridines / chemistry
  • Pyridines / pharmacology
  • Pyrroles / chemical synthesis*
  • Pyrroles / chemistry
  • Pyrroles / pharmacology
  • Quinoxalines / chemical synthesis*
  • Quinoxalines / chemistry
  • Quinoxalines / pharmacology
  • Rats
  • Structure-Activity Relationship

Substances

  • Antimalarials
  • Hemeproteins
  • Pyrazines
  • Pyridines
  • Pyrroles
  • Quinoxalines
  • hemozoin