Planta Med 2014; 80 - P2O11
DOI: 10.1055/s-0034-1395005

New unexpected iridoid glucosides from Manulea sp.

C Gousiadou 1, SR Jensen 1, CH Gotfredsen 1, T Kokubun 2
  • 1Department of Chemistry, Technical University of Denmark, DK-2800, Lyngby, Denmark
  • 2Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, United Kingdom

Secoiridoids most likely formed by biosynthesis from loganic acid were found in two plants of the family Scrophulariaceae s.s., Manulea corymbosa L. f. and M. altissima L. f. From an extract of M. corymbosa were isolated four known secoiridoid glucosides (1 – 4), 10 new monoterpenoidesters of secologanol, namely, manuleosides A-I (5 – 11, 13, 14) and dimethyl rhodanthoside A (12), and four new phenylpropanoid esters of carbocyclic iridoid glucosides, manucorymbosides I-IV (15 – 18) [1]. From an extract of M. altissima were isolated four known iridoid glucosides eustomoside, eustoside, secoxyloganin and secologanoside and 1 new ester of adoxoside [2], namely altissimoside. The structures were elucidated using 1D and 2D NMR spectroscopy. The presence of secoiridoids apparently derived from loganic acid in the family Scrophulariaceae is unprecedented and greatly unexpected [1].

Acknowledgements: The research project is implemented within the framework of the Action “Supporting Postdoctoral Researchers” of the Operational Program “Education and Lifelong Learning” and is co-financed by the European Social Fund (ESF) and the Greek State.

Keywords: Manulea, Scrophulariaceae, Secoiridoid glucosides, Iridoid glucosides, Chemotaxonomy

References:

[1]Gousiadou, C., Kokubun, T., Gotfredsen, C. H., Jensen, S. R., 2014. Unexpected Secoiridoid Glucosides from Manulea corymbosa. J. Nat. Prod. 77 (3), pp 589 – 595.

[2] Damtoft, S., Jensen, S. R., Nielsen, B. J., 1981. Carbon-13 and proton NMR spectroscopy as a tool in the configurational analysis of iridoid glucosides. Phytochemistry 20, 2717 – 2732.