A new iridoid glucoside, 8-O-acetylshanzhiside (1), was isolated from the aerial parts of Phlomis tuberosa, together with two known iridoid glucosides, shanzhiside methyl ester and lamalbide. The known phenylethanoid glycosides acteoside and forsythoside B were also obtained and characterized. The structure of 1 was determined by means of 1D - and 2DNMR spectroscopic evidence.
From the methanolic extract of the underground parts of Globularia cordifolia, a new iridoid glycoside, 5-hydroxydavisioside (1) and a new bisiridoid glycoside, globuloside C (2) were isolated along with six known iridoid glycosides, aucubin, melampyroside, monomelittoside, globularifolin, alpinoside and asperuloside. The structures of the isolates were established by 1D and 2D NMR spectroscopy in combination with IR, UV and MS analyses.
From the aerial parts of Ajuga salicifolia (L.) Schreber, a new ionone glycoside (3β-hydroxy- 7,8-dihydro-4-oxo-β-ionol-9-O-β-ᴅ-glucopyranoside) was isolated, along with the known compounds, corchoionoside C, 8-O-acetylmioporoside, ajugol, harpagide, 8-O-acetylharpagide, lavandulifolioside and leonosides A and B. This is the first report of the occurrence of ionone glycosides and 8-O-acetylmioporoside in Ajuga species. Ajugol, lavandulifolioside, leonoside A and B were isolated for the first time from Ajuga salicifolia. The structures were elucidated by means of 1D-, 2D-NMR spectroscopy, and HR-MALDI mass spectrometry.
Two new iridoids, 10-O-benzoylglobularigenin (1) and dumuloside (2) were isolated from the aerial parts of Globularia dumulosa together with seven known iridoid glucosides, davisioside (3), aucubin (4), melampyroside (5), catalpol (6), 10-O-benzoylcatalpol (7), alpinoside (8) and deacetylalpinoside (9). Three phenylethanoid glycosides, verbascoside, decaffeoylverbascoside, leucosceptoside A and three flavone glucosides, pectolinarigenin 7-O-β-ᴅ-glucopyranoside, nepetin 7-O-β-ᴅ-glucopyranoside, demethoxycentaureidin 7-O-β-ᴅ-glucopyranoside were also isolated and characterized. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, HR-MALDIMS, 1D- and 2D NMR) methods.
From the underground parts of Thalictrum orientale Boiss., a new phenolic compound 1 was isolated in addition to one known cyanoglycoside, lithospermoside (2). For the structure elucidation of all compounds, 1D- and 2D-NMR techniques (DEPT, COSY, HMBC, HSQC) and MS (HR-MALDI) were used. The structure of the new compound was established as 2-(4′-hydroxyphenyl)-nitroethane-4′-O-[β-xylopyranosyl-(1→6)-β-glucopyranoside] (1).
A new phenylethanoid tetraglycoside, physocalycoside (2), was isolated from the aerial parts of Phlomis physocalyx. Its structure was identified as 3-hydroxy-4-methoxy-β-phenyl-ethoxy-O-[α-ʟ-rhamnopyranosyl-(1→2)-α-ʟ-rhamnopyranosyl-(1→3)]-4-O-feruloyl-[β-ᴅ- glucopyranosyl-(1→6)]-|β-ᴅ-glucopyranoside, on the basis of spectroscopic evidence. In addition, one known iridoid glucoside, lamiide (1) and five known phenylethanoid glycosides, wiedemannioside C (3), verbascoside (= acteoside) (4). leucosceptoside A (5), martynoside (6), and forsythoside B (7) were also characterized. Compounds 2-7 demonstrated radical scavenging properties towards the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.