Externally accumulated flavonoid aglycones have been found for the first time in Nonea species. They exhibit only flavones, one of them being the rare tricetin-4'-methyl ether. Within the subfamily Boraginoideae, exudate flavonoids appear to be a rare character.

Flavonoids obtained from Sideritis species (Lamiaceae), S. raeseri and S. scardica, grown in Macedonia were studied. Qualitative and quantitative analyses of the flavonoid aglycones were performed using high-performance liquid chromatography (HPLC) with a UV diode array detector. Extracts were prepared by acid hydrolysis in acetone, re-extraction in ethyl acetate and evaporation to dryness; the...

The methanolic extract of the aerial parts of Salvia leriaefolia (labiatae) afforded 5-hydroxy-4´, 6, 7-trimethoxy flavone (Salvigenin) and (5,4´-dihydroxy-7-methoxy flavone (Genkwanin). The structures of the isolated compounds were elucidated using 1 and 2 D-NMR, IR, UV and MS.

The structural specificity of the monocarboxylic acid transporter (MCT) for the transport of phenolic acids was investigated by measuring the inhibitory effect on the fluorescein transport in Caco-2 cell monolayers. Although most of the monohydroxylated derivatives had an inhibitory effect, the di- and tri-hydroxylated ones did not. The methoxylated derivatives were more inhibitory than the hyd...