Phytogrowth-inhibitory lactones derivatives of glaucolide B.
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 microM, 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 microM, 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 microM 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.
Barbosa
Luiz Claúdio de A
LC
Departamento de Química, Universidade Federal de Vicosa, 36571-000 Vicosa, MG, Brazil. lcab@ufv.br
Costa
Adilson V
AV
Piló-Veloso
Dorila
D
Lopes
Joao Luiz C
JL
Hernandez-Terrones
Manuel G
MG
King-Diaz
Beatriz
B
Lotina-Hennsen
Blas
B
D027721:Amaranthus / Q000187:drug effects; D018525:Germination / Q000187:drug effects; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008129:Lolium / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development; D012639:Seeds / Q000187:drug effects / Q000502:physiology; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D029921:Trifolium / Q000187:drug effects; D035741:Vernonia / Q000737:chemistry*
D007783:Lactones; D010936:Plant Extracts; D012717:Sesquiterpenes; C065496:glaucolide B