Demethoxyencecalin

[Demethoxyencecalin and Thymol derivatives from Arnica sachalinensis1.].[Pubmed:17345336]

Planta Med. 1986 Oct;(5):349-51.

From the flowers of ARNICA SACHALINENSIS the chromene desmethoxyencecalin, 10-acetoxy-8,9-epoxy-3- O-isobutyrylthymol, and 10-acetoxy-8-hydroxy-9-isobutyryloxythymol were isolated and their structures established by mass spectrometry (13)C-, and (1)H-NMR spectroscopy.

Antifungal activity of a new phenolic compound from capitulum of a head rot-resistant sunflower genotype.[Pubmed:18034282]

J Chem Ecol. 2007 Dec;33(12):2245-53.

In a previous study, we observed that bract and corolla extracts from a Sclerotinia sclerotiorum-resistant sunflower contained high amounts of the known coumarins scopoletin, scopolin, and ayapin. There was a correlation between coumarin concentration and disease resistance. Thin layer chromatography showed higher concentrations of three other compounds in the resistant genotype when compared to the susceptible. A bioassay-directed purification that used column chromatography and HPLC allowed the isolation of a new compound, 3-acetyl-4-acetoxyacetophenone, and known compounds, Demethoxyencecalin and 3-acetyl-4-hydroxyacetophenone. Structures were assigned from spectral data, and bioactivities were characterized by in vitro bioassays against S. sclerotiorum. The new compound, 3-acetyl-4-acetoxyacetophenone, had an antifungal activity similar to the coumarin ayapin, previously described as a potent Sclerotinia inhibitor. The speed and simplicity by which these compounds can be detected make them suitable for use in screening procedures that may identify genotypes with valuable levels of resistance. A screening of seven sunflower genotypes in a field experiment showed a correlation between these compounds and resistance to Sclerotinia.

Accumulation and Biotransformation of Chromenes and Benzofurans in a Cell Suspension Culture of Ageratina adenophora.[Pubmed:17269074]

Planta Med. 1987 Oct;53(5):488-92.

A cell suspension culture of AGERATINA ADENOPHORA was shown to yield several novel chromene and benzofuran derivatives in minute amounts that were different to the compounds found in seedlings of the same species. The structure elucidation of the new compounds is described. When two of the seedling chromenes (Demethoxyencecalin and demethylencecalin) were fed to the cell suspension culture, one biotransformation product each was obtained in high yields (80%) that originated from a hydroxylation at one of the geminal methyl groups of the chromene heterocycle. These products accumulated largely in the growth media even though the presence of cells was necessary for the biotransformations to occur. When the third seedling chromene (encecalin) was fed to the cell auspension culture, no significant biotransformation was noted but several of the benzofurans present as cell culture metabolites showed a significantly increased accumulation in the growth media of the treated cultures. This increased accumulation of benzofurans was found to be inducible also by adding yeast extract to the cell culture. The metabolism of chromenes and bezofurans in the cell suspension culture is discussed.