Ajugol

Phytochemistry, 2005, 66(3):355-62.

Anti-protozoal and plasmodial FabI enzyme inhibiting metabolites of Scrophularia lepidota roots.[Pubmed: 15680992 ]

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.
METHODS AND RESULTS:
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.

Cancer Lett . 2017 Sep 10;403:195-205.

Bruceine D inhibits hepatocellular carcinoma growth by targeting β-catenin/jagged1 pathways[Pubmed: 28645563]

Abstract Hepatocellular carcinoma (HCC) is known for high mortality and limited available treatments. Aberrant activation of the Wnt and Notch signaling pathways is critical to liver carcinogenesis and progression. Here, we identified a small molecule, bruceine D (BD), as a Notch inhibitor, using an RBP-Jκ-dependent luciferase-reporter system. BD significantly inhibited liver tumor growth and enhanced the therapeutic effects of sorafenib in various murine HCC models. Mechanistically, BD promotes proteasomal degradation of β-catenin and the depletion of its nuclear accumulation, which in turn disrupts the Wnt/β-catenin-dependent transcription of the Notch ligand Jagged1 in HCC. Our findings provide important information about a novel Wnt/Notch crosstalk inhibitor that is synergistic with sorafenib for treatment of HCC, and therefore have high clinical impact. Keywords: BD; Hepatocellular carcinoma; Jagged1; Sorafenib; Wnt/Notch crosstalk; β-catenin.

Volume 23, Issue 11, 1982, Pages 1215-1216

Structural revision of ajugol and myoporoside[Reference: WebLink]

METHODS AND RESULTS:
An analysis of existing 13C NMR data shows that the structures reported for the iridoid glucosides Ajugol and myoporoside should be interchanged.
CONCLUSIONS:
Consequently, the structures of ajugoside and laterioside, both acyl-derivatives of Ajugol, as well as that of 8-O-acetyl-myoporoside need revision.