142808-76-2Relevant academic research and scientific papers
Developing new herbicide models from allelochemicals
Macias, Francisco A.,Galindo, Juan C. G.,Molinillo, Jose M. G.,Castellano, Diego,Velasco, Paul F.,Chinchilla, David
, p. 662 - 665 (1999)
Plants contain allelochemicals which are their own defence systems and can act as herbicides. Selected examples of guaianolides and heliannuols, which are sesquiterpenes, are discussed in the context of their potential use as natural herbicide templates.
Sesquiterpene lactones with potential use as natural herbicide models. 2. Guaianolides
Macias, Francisco A.,Galindo, Juan C. G.,Castellano, Diego,Velasco, Raul F.
, p. 5288 - 5296 (2007/10/03)
A structure-activity study to evaluate the effect of 17 guaianolide sesquiterpene lactones (in a range of 100-0.001 μM) on the growth and germination of several mono- and dicotyledon target species is accomplished. Results are compared with those obtained in the same bioassay with an internal standard, the commercial herbicide Logran, to validate the results with a known active formulation and to compare the results with a commercial product to test their potential use as natural herbicide models. Specific conditions for the selective mono- or polyhydroxylation of guaianolides using the SeO2/tert-butyl hydroperoxide system are presented and discussed. The high regio- and stereo-selectivities of the reaction are explained through the specific structural requirements of the bulky first adduct formed during the ene reaction. These compounds appear to have deeper effects on the growth of either monocots or dicots than the previously tested germacranolides. Otherwise, the lactone group seems to be necessary for the activity, though it does not necessarily need to be unsaturated. However, the presence of a second and easily accessible unsaturated carbonyl system greatly enhances the inhibitory activity. Lipophilicity and the stereochemistry of the possible anchoring sites are also crucial factors for the activity. Finally, the levels of growth inhibition obtained with some compounds on dicots or monocots are totally comparable to those of Logran and allow proposing them as lead compounds.
POTENTIAL ALLELOPATHIC ACTIVITY OF SEVERAL SESQUITERPENE LACTONE MODELS
Macias, Francisco A.,Galindo, Juan Carlos G.,Massanet, Guillermo M.
, p. 1969 - 1978 (2007/10/02)
A collection of 12 natural and synthetic sesquiterpene lactones with eudesmanolide, melampolide, cis,cis-germacranolide, and guaianolide skeletons have been prepared and tested as allelochemicals.The effect of a series of aqueous solutions at 10-4-10-9 M of this collection is evaluated.The specific structural requirements related to their activity is discussed.The natural sesquiterpene lactones soulangianolide A, melampomagnolide A and B, zaluzanin C and isozaluzanin C have been synthesized from costunolide, parthenolide and dehydrocostuslactone using SeO2 and tert-butylhydroperoxide.The structures of the synthetic compounds were established by NMR spectroscopy. Key Word Index - Sesquiterpene lactones; melampolides; cis,cis-germacranolides; guaianolides; eudesmanolides; allelopathy; Lactuca sativa.
