Pinar Akbay

Iridoid and bisiridoid glycosides from Globularia cordifolia

Abstract 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.

Novel Antileukemic Sterol Glycosides from Ajuga salicifolia

Two novel and three new sterol glycosides were isolated from the MeOH ext. of the aerial parts of Ajuga salicifolia (L.) Schreber. The structures of the compds. were elucidated as (3R,16S,17S,20R,22S,23S,24S,25S)-16,23:16,27:22,25-triepoxy-3-(beta -D-glucopyranosyloxy)coprostigmast-7-en-17-ol (I), (3R,16S,17S,20R,22S,23S,24S,25S)-16,23:16,27:22,25-triepoxy-3-{[beta -D-glucopyranosyl-(1->2)-beta -D-glucopyranosyl]oxy}coprostigmast-7-en-17-ol (II), (3R,16S,17R,20S,22R,24S,25S)-22,25-epoxy-3,27-bis(beta -D-glucopyranosyloxy)coprostigmast-7-en-16-ol (III), (3R,16S,17R,20S,22R,24S,25S)-22,25-epoxy-3-{[beta -D-glucopyranosyl-(1->2)-beta -D- glucopyranosyl]oxy}-27-(beta -D-glucopyranosyloxy)coprostigmast-7-en-16-ol (IV), and (3R,16R,17S,20R,22S,23S,24S,25S)-22,25-epoxy-3-(beta -D-glucopyranosyloxy)coprostigmast-7-ene-16,17,23,27-tetrol 27-acetate (V) by means of 1D and 2D NMR spectroscopy and HR-MALDI mass spectrometry. The novel compds. which consist of three addnl. ring systems at the coprostigmastane skeleton, were named ajugasalicioside A (I) and B (II), and the new compds. C (III), D (IV) and E (V). In cytotoxicity assays (HeLa cells, Jurkat T cells, and peripheral mononuclear blood cells), ajugasaliciosides A-D specifically inhibited the viability and growth of Jurkat T-leukemia cells at concns. below 10 micro M. Ajugasalicioside A (I; IC50 = 6 micro m) and C (III: IC50 = 3 micro M) were the most active compds. I induced cell-cell contact, inhibited Jurkat T cell proliferation. and up-regulated mRNA levels of the cell-cycle regulator cyclin D1, which might be an indication for cell differentiation. Furthermore, I down-regulated the mRNA levels of the NF-kB subunit p65 in a concn.-dependent manner. These effects were not found for ajugasalicioside B (II), which has an addnl. glucose unit, and the onset of cytotoxicity of II (IC50 = 10 micro M) was delayed by 24 h.

Ionone, iridoid and phenylethanoid glycosides from Ajuga salicifolia.

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.

Iridoids from Globularia dumulosa.

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.

Physocalycoside, a new phenylethanoid glycoside from Phlomis physocalyx Hub.-Mor.

Abstract 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.

Iridoid and Phenylethanoid Glycosides from Phlomis tuberosa L.

Abstract 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.

Thalictricoside, a new phenolic compound from Thalictrum orientale.

Abstract 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).