RESUMEN
Twelve novel longifolene-derived primary amine carboxylates were synthesized and evaluated for herbicidal activity. The structures of title compounds were confirmed by Fourier-transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR), 13C NMR, and high-resolution mass spectrometry. The results showed that all the synthesized compounds exhibited higher herbicidal activity than the corresponding carboxylic acids involved in the reaction and the commercial herbicide glyphosate; some of them even possessed inhibition rates of 100% against Lolium multiflorum Lam. and Brassica campestris at low concentrations (0.039-0.313 mmol/L). Moreover, structural factors, including types of carboxylates and carbon chain length, had a great influence on the herbicidal performance. The herbicidal activity of dicarboxylates was similar to or much higher than that of corresponding monocarboxylates and glyphosate. Furthermore, compound 5l was found to be the most active candidate against the root and shoot growth of L. multiflorum Lam. and B. campestris with half maximal inhibitory concentrations (IC50) of around 0.010 and 0.023 mmol/L. The present work indicated that those prepared compounds have great potential to serve as high-performance botanical herbicides used at low doses.
Asunto(s)
Aminas , Brassica , Ácidos Carboxílicos , Herbicidas , Lolium , Herbicidas/farmacología , Herbicidas/química , Herbicidas/síntesis química , Brassica/efectos de los fármacos , Brassica/crecimiento & desarrollo , Brassica/química , Lolium/efectos de los fármacos , Lolium/crecimiento & desarrollo , Aminas/química , Aminas/farmacología , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacología , Control de Malezas , Relación Estructura-Actividad , Malezas/efectos de los fármacos , Malezas/crecimiento & desarrollo , Estructura MolecularRESUMEN
Twelve novel carane-3,4-diol derivatives were designed, synthesized, and evaluated for their herbicidal activities against Lolium multiflorum Lam. and Brassica campestris for the first time. The relationships between the chemical structural factors, including types, the number or the carbon chain length of functional groups, associated with the lipophilicity and the herbicidal activity of the tested compounds were also discussed. The results showed that most of newly synthesized compounds had a dose-dependent, herbicidal activity against the root and shoot growths of Lolium multiflorum Lam. and Brassica campestris. Compared to carane-3,4-diol, most of the target derivatives possessed improved lipophilicity and certain solubilities in representative solvents with different polarities. Particularly, ester derivatives 3a-3b and 3e can be dissolved or dispersed in water, but also displayed higher herbicidal activity against Lolium multiflorum Lam. and Brassica campestris than other ester derivatives. The 50 % inhibitory concentration (IC50) value of compound 3e against shoot growth of Brassica campestris (0.485â mmol/L) was superior to that of commercial herbicide glyphosate (1.14â mmol/L), indicating that the potential application as a water-based herbicide for Brassica campestris control.