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On-line version ISSN 1806-9681
HERNANDEZ-TERRONES, M.G. et al. Phytochemistry and allelophatic study of Pterodon emarginatus stem extract. Planta daninha [online]. 2007, vol.25, n.4, pp. 755-762. ISSN 1806-9681. http://dx.doi.org/10.1590/S0100-83582007000400012.
Allelopathy is one of the natural phenomena little studied in the cerrado. It is the result of the release of substances capable of stimulating or inhibiting the growth of other plants. The objective of this work was to evaluate the allelophatic action of the white sucupira (Pterodon emarginatus) stem extract on the germination and development of colonião grass (Panicum maximum) under germination, root and aerial part development of colonião grass (Panicum maximum) root and aerial part. Germination assays carried out in Petri dishes confirmed that the methanolic (200 ppm) extract inhibited the growth of hypocotyl (75%), root (83%), and germination (30%) of colonião grass. The greenhouse results obtained were: hypocotyl 83%, root 80% and germination 63%, but at a concentration of 400 ppm. Methanolic extract fractions did not reproduce the results cited above. The most active fraction (dichloromethane/chloroform) was analyzed by GC/MS. It contains mainly long-chain aliphatic compounds such as phytol (13.5%), oleic acid (12.8%), methyl linolelaidate (10.9%) and palmitic acid (6.9%); 1,2,4-trimethyl- and isopropenylbenzene (12.2%); two isomeric ketones (isopropenyl methyl and 3-penten-2-one) (7.3%) were also detected. Three unknown compounds were also important: one with a low molecular weight (98 Da, 13.5%) and two of high molecular weight (13.6%).
Keywords : allelopathic activity; volatile extractives; methanolic extract.