Alpha-Pyrone Glycosides From Scutellaria Salviifolia Benth

Abstract

Scutellaria salviifolia Benth. is an endemic species growing in Turkey that belongs to the family Lamiaceae. As a result of a phytochemical study on the aerial parts of S. salviifolia Benth., two new and 10 known compounds were isolated from the aqueous fraction of methanolic extract. The new compounds are methyl-ff-pyrone glucosides, 3,4-dihydroxy-6-methylpyran-2-one 3-O-beta-glucopyranoside (=scusalvioside A, 1), and 3,4-dihydroxy-6-methylpyran2- one 3-O-beta-(6 `-O-E-caffeoyl) glucopyranoside (=scusalvioside B, 2) with new skeletal structures. Along with them, 3 phloroglucinol glucosides [phlorin (3), tadehaginoside (4), and 6 `'-O-Z-p-coumaroyl phloroglucinol-1-O-beta-glucopyranoside (5)], 6 flavonoids [apigenin (6), apigenin 5-O-beta-glucopyranoside (7), isoschaftoside (8), luteolin 7O -beta-glucuronide (9), luteolin 4'-O-beta-glucopyranoside (10), and hispidulin (11)], and one phenylethanoid glycoside [martynoside (12)] were also isolated as known compounds. Compounds 2 and 8 were isolated as a mixture. Structure elucidations of the isolated compounds were carried out using UV, H-1 NMR, C-13 NMR, 2D NMR, and HR-ESI-MS analyses. Moreover, the phenylethanoid glycosides acteoside (13) and leucosceptoside A (14) were also detected in the plant by HPLC-DAD study. Tadehaginoside, 6 `'-O-Z-p-coumaroyl phloroglucinol-1-O-beta-glucopyranoside, and luteolin 4 `-O-fi-glucopyranoside were reported for the first time from a Scutellaria species with this study.