Three Chalconoids and a Pterocarpene from the Roots of Tephrosia aequilata

Molecules. 2017 Feb 20;22(2):318. doi: 10.3390/molecules22020318.


In our search for new antiplasmodial agents, the CH₂Cl₂/CH₃OH (1:1) extract of the roots of Tephrosia aequilata was investigated, and observed to cause 100% mortality of the chloroquine-sensitive (3D7) strain of Plasmodium falciparum at a 10 mg/mL concentration. From this extract three new chalconoids, E-2',6'-dimethoxy-3',4'-(2'',2''-dimethyl)pyranoretrochalcone (1, aequichalcone A), Z-2',6'-dimethoxy-3',4'-(2'',2''-dimethyl)pyranoretrochalcone (2, aequichalcone B), 4''-ethoxy-3''-hydroxypraecansone B (3, aequichalcone C) and a new pterocarpene, 3,4:8,9-dimethylenedioxy-6a,11a-pterocarpene (4), along with seven known compounds were isolated. The purified compounds were characterized by NMR spectroscopic and mass spectrometric analyses. Compound 1 slowly converts into 2 in solution, and thus the latter may have been enriched, or formed, during the extraction and separation process. The isomeric compounds 1 and 2 were both observed in the crude extract. Some of the isolated constituents showed good to moderate antiplasmodial activity against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum.

Keywords: Tephrosia aequilata; aequichalcone A; aequichalcone B; aequichalcone C; antiplasmodial; chalcone; pterocarpene; retrochalcone.

MeSH terms

  • Antimalarials / chemistry
  • Chalcones / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Plant Extracts / chemistry*
  • Plant Roots / chemistry*
  • Pterocarpans / chemistry*
  • Tephrosia / chemistry*


  • Antimalarials
  • Chalcones
  • Plant Extracts
  • Pterocarpans