Phytogrowth-Inhibitory Lactones Derivatives of Glaucolide B

• Published in: Zeitschrift für Naturforschung C. A journal of biosciences Vol. 59; no. 11; pp. 803 - 810
• Main Authors: Barbosa, Luiz Claúdio de A., Costa, Adilson V., Piló-Veloso, Dorila, Lopes, Joao Luiz C., Hernandez-Terrones, Manuel G., King-Diaz, Beatriz, Lotina-Hennsen, Blas
• Format: Journal Article
• Language: English
• Published: Germany Verlag der Zeitschrift für Naturforschung 01.11.2004
• Subjects: Amaranthus - drug effects; Germination - drug effects; Germination and Growth Inhibition; Herbicidal Activity; Lactones - chemistry; Lactones - isolation & purification; Lactones - pharmacology; Lolium - drug effects; Magnetic Resonance Spectroscopy; Molecular Structure; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Roots - drug effects; Plant Roots - growth & development; Plant Shoots - drug effects; Plant Shoots - growth & development; Seeds - drug effects; Seeds - physiology; Sesquiterpene Lactones; Sesquiterpenes - chemistry; Sesquiterpenes - isolation & purification; Sesquiterpenes - pharmacology; Trifolium - drug effects; Vernonia - chemistry
• ISSN: 0939-5075; 1865-7125
• DOI: 10.1515/znc-2004-11-1207

The sesquiterpene lactone glaucolide B (1), isolated from Vernonia fruticulosa (Asteraceae), was transformed into six lactones (2-7). The structures of the products were elucidated by spectroscopic analysis. A series of solutions of compounds 1-7, at 200 μᴍ, were tested on the germination and on the root and shoot growth of the dicotyledons Physalis ixocarpa and Trifolium alexandrinum and of the monocotyledons Lolium multiflorum and Amaranthus hypochondriacus. Lactone 5 exhibited clear selectivity towards dicotyledonous species at 200 μᴍ, with an average inhibition of 90% on the germination of P. ixocarpa. Lactones 1, 3 and 4 had a greater effect on root length of monocotyledonous species, inhibiting around 70% at 200 μᴍ in L. multiflorum. It seems that the diol function is required in lactones 4-6 to increase the activity, the polarity in the molecule might be required to reach its target.