Apple scab control with grapefruit seed extract: no alternative to chemical fungicides

The growth inhibiting effect of four commercially available grapefruit seed extracts on the causal organism of apple scab Venturia inaequalis was tested. Germination of the conidia of Venturia inaequalis was pronouncedly inhibited by all tested extracts. The commercial products were analyzed by high pressure liquid chromatography and thin layer chromatography. All samples contained at least one preserving agent. These substances were identified as either benzethonium chloride, benzalkonium chloride, methyl parabene or propyl parabene. Freshly prepared extracts from seeds of grapefruits (Citrus paradisi) did not inhibit the germination of Venturia inaequalis. It was therefore concluded that the antifungal effect of grapefruit seed extracts is caused by the added preservatives

Phenolics from Rhagadiolus stellatus (Asteraceae, Cichorieae)

Rhagadiolus stellatus Gaertn., a Mediterranean member of the Cichorieae tribe of the Asteraceae family used as a food plant, was analyzed for its spectrum of phenolic compounds. Kaempferol 3-O-β-glucoside 1, kaempferol 3-O-β-rutinoside (nicotiflorin) 2, quercetin 3-O-β-glucoside 3, and luteolin 4 were isolated from the n-butanol layer of a methanolic extract of whole plants of Rh. stellatus of Spanish origin by repeated Sephadex LH-20 column chromatography. Structures were determined based on NMR and MS data as well as by comparison with literature data. Additionally, chlorogenic acid 5 and 3,5-dicaffeoylquinic acid 6 were detected by HPLC/DAD and HPLC/MS. Chemosystematic implications of the presented findings are discussed in comparison with other members of the Cichorieae tribe

A new eudesmane derivative from Leontodon tuberosus

Besides the known compounds 2,4,6-trihydroxyacetophenone 4-O-β -D-glucopyranoside and syringaresinol 4'-O-β -D-glucopyranoside, the novel sesquiterpenoid 1,2-dehydro-3-oxocostic acid β -D-glucopyranoside ester was isolated from Leontodon tuberosus L. and its structure established by mass spectrometry and 1D-and 2D-NMR spectroscopy. Additionally, a number of fatty and phenolic acids was identified in the crude methanolic extract by HPLC-DAD and HPLC-MS. The chemosystematic impact of the new sesquiterpenoid is discussed briefly

Phenylpropanoids and Polyacetylenes from Ligusticum mutellina (Apiaceae) of Tyrolean Origin

Roots of Ligusticum mutellina (L.) CRANTZ afforded five major compounds, the phenylpropanoids trans-isoelemicin (1), sarisan (2), and trans-isomyristicin (3), and the polyacetylenes falcarindiol (4) and falcarindiol-3-O-acetate (5). Structures were assigned by 1D- and 2D-NMR spectroscopy. Close inspection of the NMR spectra of falcarindiol-3-O-acetate (5) and comparison with the literature revealed that published NMR data for this compound are most probably attributable to cis or trans Δ2-isofalcarindiol-1-O-acetate (6a/6b). 1H and 13C NMR data for falcarindiol-3-O-acetate are given and trans-isoelemicin (1), sarisan (2), and trans-isomyristicin (3), falcarindiol (4), and falcarindiol-3-O-acetate (5) are reported for the first time from Ligusticum mutellina. Chemosystematic and ethnopharmacological implications of the findings are discussed briefly