1. Academic Validation
  2. Anti-protozoal and plasmodial FabI enzyme inhibiting metabolites of Scrophularia lepidota roots

Anti-protozoal and plasmodial FabI enzyme inhibiting metabolites of Scrophularia lepidota roots

  • Phytochemistry. 2005 Feb;66(3):355-62. doi: 10.1016/j.phytochem.2004.11.013.
Deniz Tasdemir 1 Nadide Deniz Güner Remo Perozzo Reto Brun Ali A Dönmez Ihsan Calis Peter Rüedi
Affiliations

Affiliation

  • 1 Institute of Organic Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. deniz@oci.unizh.ch
Abstract

The ethanolic root extract of Scrophularia lepidota, an endemic plant of the Turkish flora, has been investigated for its anti-protozoal and inhibitory effect towards plasmodial enoyl-ACP reductase (FabI), a key Enzyme of fatty acid biosynthesis in Plasmodium falciparum. Chromatographic separation of the extract yielded 10 Iridoids (1-10), two of which are new, and a known phenylethanoid glycoside (11). The structures of the new compounds were determined as 3,4-dihydro-methylcatalpol (8) and 6-O-[4''-O-trans-(3,4-dimethoxycinnamoyl)-alpha-L-rhamnopyranosyl]aucubin (scrolepidoside, 9) by spectroscopic means. The remaining metabolites were characterized as catalpol (1), 6-O-methylcatalpol (2), aucubin (3), 6-O-alpha-L-rhamnopyranosyl-aucubin (sinuatol, 4), 6-O-beta-D-xylopyranosylaucubin (5), ajugol (6), ajugoside (7), an iridoid-related aglycone (10) and angoroside C (11). Nine isolates were active against Leishmania donovani, with the new compound 9 being most potent (IC50 6.1 microg/ml). Except for 4, all pure compounds revealed some trypanocidal potential against Trypanosoma brucei rhodesiense (IC50 values 29.3-73.0 microg/ml). Only compound 10 showed moderate anti-plasmodial (IC50 40.6 microg/ml) and FabI Enzyme inhibitory activity (IC50 100 microg/ml). 10 is the second natural product inhibiting the fatty acid biosynthesis of Plasmodium falciparum.

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