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Thomas J Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • lignans in flowering aerial parts of Linum species chemodiversity in the light of systematics and phylogeny
    Phytochemistry, 2010
    Co-Authors: Thomas J Schmidt, Elisabeth Fuss, Shiva Hemmati, M Klaes, Belma Konuklugil, Abdolali Mohagheghzadeh, Iliana Ionkova, Wilhelm A Alfermann
    Abstract:

    The aerial parts of 54 accessions representing 41 Linum species and four species of related genera were analysed for lignans by means of HPLC-ESI/MS-MS-UV/DAD. In total, 64 different lignans of the aryltetralin-, arylnaphthalene-, aryldihydronaphthalene-, dibenzylbutyrolactone-, and furofuran type were identified. According to their lignan profile, the Linum species can be divided in two groups accumulating as major lignan types either cyclolignans of the aryltetralin-series on one hand, or aryldihydronaphthalenes/arylnaphthalenes, on the other. Five of the investigated Linum species did not contain any detectable amounts of these lignans under the chosen analytical conditions. Furthermore, none of the lignans identified in Linum species was detectable in representatives of three related genera, namely, Reinwardtia (Linaceae, Linoideae), Hugonia and Indorouchera (Linaceae, Hugonioideae). The two species groups differing in the types of the dominating cyclolignans comprise representatives of the major taxonomic sections. Representatives of sections SylLinum, CathartoLinum and Linopsis accumulate mainly aryltetralins while those of sections Linum and DasyLinum were found to contain mainly aryldihydronaphthalenes/-naphthalenes. These phytochemical data correlate very well with a recent study on the molecular phylogeny of Linum/Linaceae, where a subdivision of Linum into two major clades comprising representatives of the two mentioned groups was found. Thus, the distribution of lignans apparently reflecting phylogenetic interrelations at the infrageneric level, a plausible scenario for the evolution of lignan biosynthesis in the genus Linum can now be presented.

  • 6 methoxypodophyllotoxin 7 o n hexanoate a new aryltetralin lignan ester from seeds of Linum flavum
    Planta Medica, 2010
    Co-Authors: M Klaes, Therese Ellendorff, Thomas J Schmidt
    Abstract:

    A new aryltetralin-type lignan, 6-methoxypodophyllotoxin-7- O-n-hexanoate, was isolated from the seeds of Linum flavum L. var. compactum (Linaceae) by silica gel column chromatography of the dichloromethane extract. This lignan, previously detected by our group in the aerial parts of several Linum species by HPLC-MS, has now been isolated for the first time, and its structure is now confirmed and fully characterized by assignment of all NMR data as well as the CD spectrum. The occurrence of aryltetralin lignans, which are well known in the case of aerial parts and roots, in the seeds of a Linum species has not been reported before.

  • pinoresinol lariciresinol reductases with different stereospecificity from Linum album and Linum usitatissimum
    Phytochemistry, 2005
    Co-Authors: Cosima B I Von Heimendahl, Katrin M Schafer, Patrik Eklund, Rainer Sjoholm, Thomas J Schmidt, Elisabeth Fuss
    Abstract:

    Abstract Recently it was found that cell cultures and plants of Linum species contain lignans of various chemical structures. The stereochemistry of these compounds differ among species. Cell cultures of L. album accumulate (−)-podophyllotoxin together with pure (−)-secoisolariciresinol. The presence of both enantiomers of the precursor pinoresinol indicates that in L. album cell cultures the reactions from pinoresinol to secoisolariciresinol are the first steps determining enantiospecificity in biosynthesis of podophyllotoxin. Seeds of L. usitatissimum contain almost enantiomerically pure (+)-secoisolariciresinoldiglucosid derived from (+)-secoisolariciresinol. A cell culture of this species contains a mixture of both enantiomers of pinoresinol and pure (+)-secoisolariciresinol. In order to get more insight into the mechanism of (−)- and (+)-secoisolariciresinol biosynthesis, respectively, we isolated a cDNA encoding pinoresinol–lariciresinol reductase (PLR) from L. album . The heterologously expressed PLR-La1 converts only (+)-pinoresinol into (−)-secoisolariciresinol. In contrast, the heterologously expressed PLR from L. usitatissimum converts only (−)-pinoresinol to (+)-secoisolariciresinol confirming the results from others. Comparison of all available PLR protein sequences resulted in a few amino acids which may be responsible for the action of the PLRs with respect to the different enantioselectivity. A mutagenesis approach could not confirm this hypothesis. Aspects about the evolution of PLRs are discussed.

Hugh D. Wilson - One of the best experts on this subject based on the ideXlab platform.

Wilhelm A Alfermann - One of the best experts on this subject based on the ideXlab platform.

  • lignans in flowering aerial parts of Linum species chemodiversity in the light of systematics and phylogeny
    Phytochemistry, 2010
    Co-Authors: Thomas J Schmidt, Elisabeth Fuss, Shiva Hemmati, M Klaes, Belma Konuklugil, Abdolali Mohagheghzadeh, Iliana Ionkova, Wilhelm A Alfermann
    Abstract:

    The aerial parts of 54 accessions representing 41 Linum species and four species of related genera were analysed for lignans by means of HPLC-ESI/MS-MS-UV/DAD. In total, 64 different lignans of the aryltetralin-, arylnaphthalene-, aryldihydronaphthalene-, dibenzylbutyrolactone-, and furofuran type were identified. According to their lignan profile, the Linum species can be divided in two groups accumulating as major lignan types either cyclolignans of the aryltetralin-series on one hand, or aryldihydronaphthalenes/arylnaphthalenes, on the other. Five of the investigated Linum species did not contain any detectable amounts of these lignans under the chosen analytical conditions. Furthermore, none of the lignans identified in Linum species was detectable in representatives of three related genera, namely, Reinwardtia (Linaceae, Linoideae), Hugonia and Indorouchera (Linaceae, Hugonioideae). The two species groups differing in the types of the dominating cyclolignans comprise representatives of the major taxonomic sections. Representatives of sections SylLinum, CathartoLinum and Linopsis accumulate mainly aryltetralins while those of sections Linum and DasyLinum were found to contain mainly aryldihydronaphthalenes/-naphthalenes. These phytochemical data correlate very well with a recent study on the molecular phylogeny of Linum/Linaceae, where a subdivision of Linum into two major clades comprising representatives of the two mentioned groups was found. Thus, the distribution of lignans apparently reflecting phylogenetic interrelations at the infrageneric level, a plausible scenario for the evolution of lignan biosynthesis in the genus Linum can now be presented.

  • Linum persicum lignans and placement in linaceae
    Phytochemistry Reviews, 2003
    Co-Authors: Abdolali Mohagheghzadeh, Shiva Hemmati, Iraj Mehregan, Wilhelm A Alfermann
    Abstract:

    Aryltetralin lignans (podophyllotoxin type) are the main lignan constituents of species belonging to Linum section SylLinum (Linaceae). Linum persicum, a perennial plant native to Iran closely related to L. album, has not yet been studied. To evaluate the lignan profile, fresh plants of L. persicumwere collected and divided into different parts and analyzed by HPLC. The main aryltetralin lignans found inL. persicumplant parts, callus and cell cultures were podophyllotoxin (PTOX), 6-methoxypodophyllotoxin (MPTOX) and α- and β-peltatin. Furthermore, the systematic relationship between L. persicum and other Linum species are discussed in the light of morphological and phytochemical aspects.

James R. Manhart - One of the best experts on this subject based on the ideXlab platform.

Michel Solignac - One of the best experts on this subject based on the ideXlab platform.

  • polymorphic microsatellite loci in Linum usitatissimum
    Molecular Ecology Notes, 2006
    Co-Authors: C Rooseamsaleg, E Carioupham, Dominique Vautrin, R Tavernier, Michel Solignac
    Abstract:

    We report the characterization of 28 polymorphic microsatellite markers in Linum usitatissimum that allow distinguishing almost all cultivars of both flax and linseed. Polymorphism was low, ranging from two to 10 alleles per locus in the 93 cultivars screened. Linkage disequilibrium was found at about a third of the pairs of loci likely due to self-fertilization and strong selection by breeders. We tested these loci for cross-amplification in nine additional species of Linum and found that three species amplified a majority of loci.

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