25 research outputs found
A new phenylethanoid triglycoside in Veronica beccabunga L
Jensen SR, Opitz S, Gotfredsen CH. A new phenylethanoid triglycoside in Veronica beccabunga L. Biochemical Systematics and Ecology. 2011;39(3):193-197.Besides the expected iridoid glucosides aucubin and catalpol as well as three known esters of the latter, Veronica beccabunga (brooklime) was shown to contain five carboxylated iridoid glucosides, namely gardoside, mussaenosidic acid, 8-epiloganic acid, arborescosidic acid and alpinoside. In addition to these compounds, the plant contained salidroside and a previously unknown caffeoyl phenylethanoid glycoside (CPG) which we have named chionoside J. The structure was elucidated mainly by 1D and 2D NMR spectroscopy to be 2 ''-(beta-glucopyranosyl)-plantamajoside. The distribution of plantamajoside and its derivatives as well as that of carbocyclic iridoids with an 8,9-double bond is briefly discussed, and it is noted that such compounds are mainly confined to the tribe Veroniceae of the Plantaginaceae. (C) 2011 Elsevier Ltd. All rights reserved
Iridoids and Anthraquinones from the Malaysian Medicinal Plant, Saprosma scortechinii (Rubiaceae)
A further investigation of the leaves and stems of Saprosma scortechinii afforded 13 compounds, of which 10 are new compounds. These were elucidated as the bis-iridoid glucosides, saprosmosides G (1) and H (2), the iridoid glucoside, 6-O-epi-acetylscandoside (3), and the anthraquinones, 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone (4), 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-β-primeveroside (5), 1,3-dihydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-β-primeveroside (6), 1,3,6-trihydroxy-2-methoxymethyl-9,10-anthraquinone (7), 1-methoxy-3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (8), 1,3,6-trihydroxy-2-hydroxymethyl-9,10-anthraquinone 3-O-β-primeveroside (9), and 3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (10). Structure assignments for all compounds were established by means of mass and NMR spectroscopies, chemical methods, and comparison with published data. The new anthraquinones were derivatives of munjistin and lucidin
Iridoid Glucosides from Veronica Hederifolia
A new iridoid glucoside, urphoside A, and six known iridoid glucosides, pikuroside, aucubin, veronicoside, catalposide, amphicoside, and verminoside, were isolated from Veronica hederifolia together with a known megastigmane glucoside, 3-hydroxy-5,6-epoxy-beta-D-ionol-9-O-beta-D-glucopyranoside, and a hexitol, dulcitol. The structures of the isolated compounds were established by the extensive 1D- and 2D-NMR spectroscopy.WoSScopu
Iridoids: The Total Synthesis of the Aglucones of (±)-8-Epiloganin and (±)-Mussaenoside Via Bicyclo |3.3.0| Octenes
The nitrone-olefin cycloaddition reaction has been used to construct cis-fused bicyclo|3.3.0| octanes or diquinanes as potential intermediates for C-11 functionalized iridoids. The isoxazolidine 7 was obtained in four steps from the commercially available 2-cyclopentene-1-acetic acid 4. Different functionalized diquinanes 8 to 19 and 22 to 24 have been prepared. As illustrative examples of iridoid synthesis, compounds 21 and 26, the O-methyl protected aglucones of (±)-8-epiloganin (2) and (±)-mussaenoside (3) have been synthesized starting from the common key-intermediate 11
Phenylethanoid and Iridoid Glycosides from Veronica Persica
A new phenylethanoid glycoside, persicoside (1) and three known phenylethanoid glycosides, acteoside (2), isoacteoside (3) and lavandulifolioside (4) were isolated from the aerial parts of Veronica persica. On the basis of spectral analyses, the structure of the new compound was elucidated to be 3,4-dihydroxy-beta-phenylethoxy-O-[beta-D- lucopyranosyl-(1-->2)]-[beta-D-glucopyranosyl-(1-->3)]-4-O-caffeoyl-beta-D-glucopyranoside. Persicoside (1) and acteoside (2) exhibited radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Beside phenylethanoid glycosides, a hexitol, dulcitol (5) and seven known iridoid glucosides, aucubin (6), veronicoside (7), amphicoside (8), 6-O-veratroyl-catalpol (9), catalposide (10), verproside (11) and verminoside (12) were isolated.WoSScopu