Síntese e avaliação da atividade herbicida de derivados da lumissantonina

• Ano de defesa: 2013
• Autor(a) principal: Moraes, Fernanda da Conceição
• Orientador(a): Alvarenga, Elson Santiago de
• Banca de defesa: Fernandes, Sergio Antônio , Muñoz, Gaspar Diaz , Flores, Milton Edgar Pereira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Agroquímica
• Departamento: Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica
• País: BR
• Palavras-chave em Português: Herbicidas; Lactonas; Amidas; Síntese orgânica
• Palavras-chave em Inglês: Herbicides; Lactones; Amides, Organic Synthesis
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2163

The sesquiterpene lactones are substances with wide occurrence in nature which show several biological activities. Considering to the necessary to develop herbicides with different modes of action due to weed resistance to known herbicides, sesquiterpene lactones can be the starting point for the search of new bioactive compounds. Thus, the aims of the present work is the synthesis of lumisantonin (2) derivatives and the evaluation of the herbicidal activity of the synthesized compounds. From lumisantonin (2), obtained by photochemical rearranging of α- santonin (1), were synthesized 15 compounds. For the achievement of lumisantonin derivatives the synthetic route included catalytic hydrogenation, epoxidation, halogenation, esterification and aminolysis reactions. The prepared substances were characterized by infrared spectroscopy, 1H NMR and 13 C NMR (1D), two-dimensional techniques HETCOR/ COSY and mass spectrometry. The phytotoxic effect of the synthesized compounds was evaluated in vitro on the growth of roots and shoots of seedlings of cucumber (Cucumis sativus) and sorghum (Sorghum bicolor). The highest phytotoxicity for sorghum was observed for compounds (2) and (9) which inhibited the growth of shoots and radicles of the seedlings. However, there was no significant effect of inhibiting for cucumber seedlings (dicot). This result suggests that the substances tested are selective for monocot plants (sorghum), and this is an important finding in the search for new compounds with herbicidal activity. However, for a more detailed conclusion about the herbicidal potential of the synthetized compounds, bioassays with other species of plants (including weeds) are required.