Chemical constituents of Digitalis viridiflora

• Published in: Planta Medica
• Main Authors: Kirmizibekmez, H, Kúsz, N, Hohmann, J
• Format: Conference Proceeding
• Language: English
• Published: 25.11.2015
• ISSN: 0032-0943; 1439-0221
• DOI: 10.1055/s-0035-1565439

The genus Digitalis (Plantaginaceae) contains biennial or perennial species. It is represented by nine species in the flora of Turkey including D. viridiflora Lindley [1]. Phenylethanoid glycosides, cardiac glycosides, steroidal saponins and pregnane glycosides constitute the main group of secondary metabolites of the genus Digitalis [2, 3]. In continuation of our systematic survey on the chemical composition of Digitalis species growing in Turkey, we recently reported five phenylethanoid glycosides from D. viridiflora as the preliminary phytochemical research [4]. Further detailed chromatographic studies on the chemical constituents of the leaves of D. viridiflora led to the isolation of a new phenylethanoid glycoside named as digiviridifloroside ( 1 ) along with a known phenylethanoid glycoside (calceolarioside A), two flavonoids (scutellarein 7- O -β-D-glucopyranoside and hispidulin 7- O -β-D-glucopyranoside), two cleroindicins (cleroindicins B and F), a nucleoside (adenosine), as well as a mixture of β-D-glucopyranosyl-(1→6)-4- O -caffeoyl-α/β-glucopyranose and 3,4-dihydroxyphenylethanol which could be an artefact formed during isolation procedure. The structure of the new compound was established as 3,4-dihydroxy-β-phenylethoxy-6- O -( E )-feruloyl-β-D-glucopyranosyl-(1→6)-4- O -( E )-caffeoyl-β-D-glucopyranoside ( 1 ) based on extensive 1D- and 2D-NMR spectroscopy as well as MS. Digiviridifloroside ( 1 ) is the third example of rare phenylethanoid glycosides obtained from the genus Digitalis bearing two aromatic acyl units; the first two ones were reported from D. lanata [5]. References: [1] Davis PH. 1978. Digitalis L. in “Flora of Turkey and the East Aegean Islands”, Vol. 6, Davis PH (ed). University Press: Edinburgh; 680 – 697. [2] Kirmizibekmez H, et al., Phytother. Res. 2014; 28: 534 – 538. [3] Calis I et al., Pharmazie 1999; 54: 926 – 930. [4] Kirmizibekmez H Rec. Nat. Prod. 2015; 9: 369 – 373. [5] Kirmizibekmez H, et al., Helv. Chim. Acta 2009; 92: 1845 – 1852.