Phenylethyl glycosides from Globularia alypum growing in Turkey

From the leaves of Globularia alypum, three new phenylethyl glycosides, namely galypumosides A (=2-(3,4-dihydroxyphenyl)ethyl O-α-rhamnopyranosyl- (1 → 3)-4-O-[(E)-caffeoyl]-6-O-[(E)-p-coumaroyl]-β-glucopyranoside; 1), B (=2-(3,4-dihydroxyphenyl)ethyl O-α-rhamnopyranosyl-(1 → 3)-4-O-[(E)-caffeoyl]-6-O-[(E)-feruloyl]-β-glucopyranoside; 2), and C (=2-(3,4-dihydroxyphenyl)ethyl O-α-rhamnopyranosyl-(1 → 3)-4-O-[(E)-caffeoyl]-6-O-menthiafoloyl-β-glucopyranoside; 3), were isolated, together with two known phenylethyl glycosides, calceolarioside A and verbascoside. Eight iridoid glucosides, catalpol, globularicisin, globularin, globularidin, globularinin, globularimin, lytanthosalin, and alpinoside, a flavon glycoside, 6-hydroxyluteolin 7-O-sophoroside, a lignan glycoside, syringaresinol 4′-O-β-glucopyranoside, and a phenylpropanoid glycoside, syringin, were also obtained and characterized. The structures of the isolates were elucidated on the basis of 1D- and 2D-NMR experiments as well as HR-MALDI-MS.