Secondary metabolites from Eremostachys laciniata

Abstract

From the aerial parts of Eremostachys laciniata (Lamiaceae), a new acidic iridoid glucoside, 5-desoxysesamosidic acid (1) was isolated in addition to thirteen known iridoid glucosides, 5-desoxysesamoside (2), sesamoside (3), 6β-hydroxy-7-epi-loganin (4), chlorotuberoside (5), 5-deoxypulchelloside I (6), lamalbide (7), lamalbidic acid (8), phloyosides I (7-epi-phlomiol) (9), and II (10), phlomiol (11), shanzhiside (12), shanzhiside methyl ester (13), and barlerin (8-O-acetylshanzhiside methyl ester) (14), four phenylethanoid glycosides, verbascoside (15), leucosceptoside A (16), martynoside (17), and forsythoside B (18), and five flavone derivatives, luteolin (19), luteolin 7-O-β-D-glucopyranoside (20), luteolin 7-O-(6″-O-β-D- apiofuranosyl)-β-D-glucopyranoside (21), apigenin 7-O-β-D- glucopyranoside (22), and apigenin 7-O-(6″-O-p-coumaroyl)-β-D- glucopyranoside (23). The structures of the metabolites were elucidated from spectroscopic (UV, IR, 1D- and 2D-NMR) and ESI-MS evidence, as well as from their specific optical rotations. The presence of these metabolites of three different classes strongly supports the close relationship of the genera Eremostachys and Phlomis.