Alpha-pyrone glycosides from Scutellaria salviifolia Benth

摘要

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-$lpha $-pyrone glucosides, 3,4-dihydroxy-6-methylpyran-2-one 3-$O$-$eta $-glucopyranoside (=scusalvioside A, 1 ), and 3,4-dihydroxy-6-methylpyran-2-one 3-$O$-$eta $-(6$'$-$O$-$E$-caffeoyl) glucopyranoside (=scusalvioside B, 2 ) with new skeletal structures. Along with them, 3 phloroglucinol glucosides [phlorin (3 ), tadehaginoside (4 ), and 6$^{prime prime} $-$O$-$Z$-$p$-coumaroyl phloroglucinol-1-$O$-$eta $-glucopyranoside (5 )], 6 flavonoids [apigenin (6 ), apigenin 5-$O$-$eta $-glucopyranoside (7 ), isoschaftoside (8 ), luteolin 7-$O$-$eta $-glucuronide (9 ), luteolin 4$'$-$O$-$eta $-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, $^{1}$H NMR, $^{13}$C 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$^{prime prime} $-$O$-$Z$-$p$-coumaroyl phloroglucinol-1-$O$-$eta $-glucopyranoside, and luteolin 4$'$-$O$-$eta $-glucopyranoside were reported for the first time from a Scutellaria species with this study.