Comparative studies of the phenolic constituents of two Verbascum Species

Abstract EN

comparative studies of the phenolic constituents of Verbascum letourne and Verbascum sinuatum revealed that the two species contained the flavonoids, luteolin-7-glucoside--methoxide, luteolin-7-diglucosides and apigenin-7-o-neohesperidoside, beside the phenolic acid derivatives, methyl gallate and 4,5-dimethoxy-3-hydroxybenzoic acid.

Meanwhile Verbascum letourneuxii contained the flavonoids, naringenin, tamarixetin-7-rutinoside and tamarixetin-7-glucoside, beside the phenolic acid caffeic, while Verbascum sinuatum contained the flavonoids, patuletin-3,7-dirhamnoside, patuletin-3-neohesperidoside and 5,7 dihydroxy--dimethoxy flavone, beside the phenolic acid chlorogenic.

On other hand, V.

letourneuxii contained the coumarins, umckalin and asculetin, while V.

sinuatum contained scopoletin-7-glucoside and asculetin.

Isolation of phenolic compounds were achieved through silica gel column and preparative paper chromatography , for flavonoid while isolation of coumarins were achieved using preparative thin layer chromatography and silica gel column for phenolic acids.

The isolated compounds were purified on sephadex LH-20 column and identified through Rf- values, colour reactions, UV, 1H-NMR, 13CNMR spectral data, mass spectra and acid hydrolysis.