Acylated flavonoids and phenol glycosides from Veronica thymoides subsp. pseudocinerea

A new acylated flavone glucoside, 3 ′-hydroxyscutellarein 7- O-(6″- O-protocatechuoyl)-β-glucopyranoside ( 1) and a new phenol glucoside, 3,5-dihydroxyphenethyl alcohol 3- O-β-glucopyranoside ( 6) were isolated from the aerial parts of Veronica thymoides subsp. pseudocinerea together with seven known flavone, phenol and lignan glycosides. The structures of the isolated compounds were determined on the basis of spectral analysis. Five known glycosides were reported for the first time in the genus Veronica. Isolated compounds exhibited potent radical scavenging activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. A new acylated flavone glucoside, 3 ′-hydroxyscutellarein 7- O-(6″- O-protocatechuoyl)-β-glucopyranoside ( 1), and a new phenol glucoside, 3,5-dihydroxyphenethyl alcohol 3- O-β-glucopyranoside ( 6) were isolated from Veronica thymoides subsp. pseudocinerea together with seven known flavone, phenol and lignan glycosides; 3 ′-hydroxyscutellarein 7- O-(6″- O-trans-feruloyl)-β-glucopyranoside ( 2), 3 ′-hydroxy, 6- O-methylscutellarein 7- O-β-glucopyranoside ( 3), luteolin 7- O-β-glucopyranoside ( 4), isoscutellarein 7- O-(6‴- O-acetyl)-β-allopyranosyl (1‴→2″)-β-glucopyranoside ( 5), 3,4-dihydroxyphenethyl alcohol 8- O-β-glucopyranoside ( 7), benzyl alcohol 7- O-β-xylopyranosyl (1″→ 2 ′)-β-glucopyranoside ( 8), and (+)-syringaresinol 4 ′- O-β-glucopyranoside ( 9). Compounds 2, 3 and 7– 9 were reported for the first time in the genus Veronica. The structures of the isolates were determined by means of spectroscopic (UV, IR, 1D and 2D NMR, HR ESI-MS) methods. Isolated compounds ( 1– 7) exhibited potent radical scavenging activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.