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Soren Rosendal Jensen - One of the best experts on this subject based on the ideXlab platform.

  • chemotaxonomic markers in digitalideae plantaginaceae
    Phytochemistry, 2005
    Co-Authors: Rilka Mladenova Taskova, Charlotte Held Gotfredsen, Soren Rosendal Jensen
    Abstract:

    Abstract In a chemosystematic investigation of Digitalideae (Plantaginaceae), the water-soluble part of extracts of two species of Digitalis , two species of Isoplexis , as well as Erinus alpinus and Lafuentea rotundifolia were studied with regard to their content of main carbohydrates, Iridoids and caffeoyl phenylethanoid glycosides (CPGs). Digitalis and Isoplexis contained sorbitol, cornoside and a number of other phenylethanoid glycosides including the new tyrosol β- d -mannopyranoside, sceptroside but were found to lack Iridoid glucosides. Erinus contained mainly glucose, the new 8,9-double bond Iridoid, erinoside, and a number of known Iridoid glucosides including two esters of 6-rhamnopyranosylcatalpol, as well as the CPG poliumoside. Finally, Lafuentea was characterized by the presence of glucose, aucubin and cryptamygin B but apparently lacked CPGs. The chemosystematic significance of the isolated compounds is discussed.

  • Veronica: Iridoids and cornoside as chemosystematic markers
    Biochemical Systematics and Ecology, 2005
    Co-Authors: Soren Rosendal Jensen, Dirk C. Albach, Takao Ohno, Renée J. Grayer
    Abstract:

    The Iridoid glucoside, ajugol, and the phenylethanoid glucoside, cornoside, have been isolated from species of Veronica (Plantaginaceae) for the first time. The presence of these compounds has been screened in 18 plant accessions belonging to 15 species of Veronica (Plantaginaceae), by isolation or NMR spectroscopy of crude extracts. In addition, the distribution of Iridoids in the genus has been reviewed, using mainly the published data of isolated compounds. Using the recent expansion and reclassification of the genus based on DNA-sequence results as the model, we find that the genus is rather homogeneous with regard to the distribution of Iridoid glucosides, aucubin and/or catalpol as well as 6-O-esters of catalpol being universally present in 10 of the 12 subgenera for which data exist. Only the two subgenera Pocilla and Chamaedrys deviate from this pattern. Pocilla is heterogeneous; in this subgenus, species in subsect. Agrestes contain the standard Iridoid garniture, while species in subsect. Biloba do not contain the 6-O-esters of catalpol, but ajugol instead. Veronica intercedens (subsect. Subracemosae) differs from the remainder of the subgenus in only containing 5-hydroxylated Iridoids (melittoside and globularifolin) and is so far the only species within the genus in which such compounds have been detected. These chemical differences are clearly reflected in the DNA-based phylogram of the subgenus. Subg. Chamaedrys appears homogeneous in lacking Iridoids or only containing these in small amounts, but instead half of the investigated species contained the phenylethanoid glucoside cornoside. The distribution of this compound in angiosperms is reviewed; cornoside often substitutes Iridoid glucosides in plants where these are expected to be present. The chemical results of Veronica fit in very well with the phylogenetic implications of the DNA-sequence results.

  • Acid Rearrangement of SecoIridoids Related to Oleuropein and Secologanin
    European Journal of Organic Chemistry, 2003
    Co-Authors: Armandodoriano Bianco, Soren Rosendal Jensen, Jens K. Olesen, Pietro Passacantilli, Alessia Ramunno
    Abstract:

    Acid treatment of an Iridoid glycoside results in the cleavage of the acetal bond between the sugar unit and the monoterpenoid aglycon. Iridoids possessing non-conjugated enol ether systems, however, undergo the hydration of the Iridoid enol ether functionality in acid medium, as well as the hydrolysis of the bond. We examined the acid rearrangement of secoIridoids such as oleuropein (1) and secologanin (2) and their reduction products oleuropeinol (3) and secologaninol (4), to examine whether similar behaviour also occurs in this case. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

  • Chemotaxonomy of the Oleaceae: Iridoids as taxonomic markers
    Phytochemistry, 2002
    Co-Authors: Soren Rosendal Jensen, Henrik Franzyk, Eva Wallander
    Abstract:

    The distribution and biosynthesis of Iridoid glucosides in the Oleaceae is reviewed and five distinct biosynthetic pathways to Iridoids have been identified in the family, deoxyloganic acid apparently being a common intermediate. Likewise, the distributions of caffeoyl phenylethanoid glycosides (CPGs), i.e. verbascoside and its analogues, as well as cornoside are listed. Iridoid glucoside data exist for 17 genera of Oleaceae and the occurrence of Iridoids from the different biosynthetic pathways correlate extremely well with the phylogenetic classification inferred from recent chloroplast DNA sequence data. Thus the tribe Fontanesieae (Fontanesia) contains "normal" secoIridoids, Forsythieae (Abeliophyllum, Forsythia) contains cornoside and/or Iridoids from the forsythide pathway, Myxopyreae (Myxopyrum, Nyctanthes) have Iridoids from the myxopyroside pathway, and finally, the two tribes Jasmineae and Oleeae (the remaining genera) both contain Iridoids from the oleoside pathway. Within Jasmineae, one group of Jasminum sp. is characterized by the presence of jasminin or similar compounds, while another group of Jasminum species and Menodora display derivatives of 10-hydroxyoleoside, compounds not present in the other group. CPGs are reported from about half of the species investigated. With regard to taxonomy at the order level, the chemical data might support a position within or close to Lamiales due to the common presence of CPGs, the Iridoids being of less significance since they are of a type that are barely found elsewhere.

  • chemotaxonomy of plantago Iridoid glucosides and caffeoyl phenylethanoid glycosides
    Phytochemistry, 2000
    Co-Authors: Nina Ronsted, Soren Rosendal Jensen, Henrik Franzyk, Edith Gobel, Carl Erik Olsen
    Abstract:

    Abstract Data for 34 species of Plantago (Plantaginaceae), including subgen. Littorella (=Littorella uniflora), have been collected with regard to their content of Iridoid glucosides and caffeoyl phenylethanoid glycosides (CPGs). In the present work, 21 species were investigated for the first time and many known compounds were found together with three new Iridoid glucosides. Of these, arborescoside and arborescosidic acid, both of the uncommon type with an 8,9-double bond, were present in several species, while 6-deoxymelittoside was found only in P. subulata. The known compounds deoxyloganic acid, caryoptoside and rehmannioside D were isolated from the genus for the first time. The earlier reported occurrence of sorbitol in the family was confirmed, and this compound was shown by NMR spectroscopy to be the main sugar in the three species investigated for this. The combined data show that CPGs are present in all species investigated. With regard to the Iridoids, the distribution patterns showed a good correlation with the classification of Rahn. Thus, aucubin is typical for the whole genus, while bartsioside and catalpol as well as 5-substituted Iridoids are each characteristic for a subgenus in the family. Finally, the close relationship between Plantago and Veronica suggested by chloroplast DNA sequence analysis, could be corroborated by the common occurrence of the rare 8,9-unsaturated Iridoids in these two genera.

Young Ho Kim - One of the best experts on this subject based on the ideXlab platform.

Xinmiao Liang - One of the best experts on this subject based on the ideXlab platform.

  • Iridoid glucosides from strychnos nux vomica
    Phytochemistry, 2003
    Co-Authors: Xiaozhe Zhang, Qing Xu, Hongbin Xiao, Xinmiao Liang
    Abstract:

    From seeds of Strychnos nux-vomica three Iridoids, 6 0 -O-acetylloganic acid, 4 0 -O-acetylloganic acid and 3 0 -O-acetylloganic acid were isolated together with two known Iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods. # 2003 Elsevier Ltd. All rights reserved.

  • Iridoid glucosides from Strychnos nux-vomica
    Phytochemistry, 2003
    Co-Authors: Xiaozhe Zhang, Hongbin Xiao, Xinmiao Liang
    Abstract:

    From seeds of Strychnos nux-vomica three Iridoids, 6'-O-acetylloganic acid, 4'-O-acetylloganic acid and 3'-O-acetylloganic acid were isolated together with two known Iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods.

Bui Huu Tai - One of the best experts on this subject based on the ideXlab platform.

Xiaozhe Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Iridoid glucosides from strychnos nux vomica
    Phytochemistry, 2003
    Co-Authors: Xiaozhe Zhang, Qing Xu, Hongbin Xiao, Xinmiao Liang
    Abstract:

    From seeds of Strychnos nux-vomica three Iridoids, 6 0 -O-acetylloganic acid, 4 0 -O-acetylloganic acid and 3 0 -O-acetylloganic acid were isolated together with two known Iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods. # 2003 Elsevier Ltd. All rights reserved.

  • Iridoid glucosides from Strychnos nux-vomica
    Phytochemistry, 2003
    Co-Authors: Xiaozhe Zhang, Hongbin Xiao, Xinmiao Liang
    Abstract:

    From seeds of Strychnos nux-vomica three Iridoids, 6'-O-acetylloganic acid, 4'-O-acetylloganic acid and 3'-O-acetylloganic acid were isolated together with two known Iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods.