Renate Spitaler

Structure of Tyrolobibenzyl D and Biological Activity of Tyrolobibenzyls from Scorzonera humilis

A novel tyrolobibenzyl derivative, 1→6-β-ᴅ-apiosyl-β-ᴅ-glucopyranosyl 4-[2-(4-hydroxyphenyl) ethyl]benzofuran-2-carboxylate 3 (tyrolobibenzyl D) was isolated from Scorzonera humilis L. and its structure established by mass spectrometry and 1D- and 2D-NMR spectroscopy. The biological activities of the new compound and related tyrolobibenzyls A-C (1-2, 4) and the semi-synthetic peracetyl derivatives of tyrolobibenzyls B (2a) and C (4a) were assessed. The results revealed no cytotoxic activity against P388 cells and neither anti-bacterial activity against Bacillus subtilis nor antifungal activity against Candida albicans and Trichophyton mentagrophytes for any of the investigated compounds. An evaluation of potential chemopreventive activity of 2, 2a, 4, and 4a also revealed no pronounced activity in any of the employed assaying systems.

A New Eudesmane Derivative from Leontodon tuberosus

Abstract 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.

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.