Estudo fitoquímico biomonitorado em Picramnia bahiensis e Thyrsodium schomburgkianum inseticidas, fungicidas e microencapsulação

• Ano de defesa: 2013
• Autor(a) principal: Kitamura, Rodrigo Ossamu Saga
• Orientador(a): Fernandes, João Batista
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Carlos
• Programa de Pós-Graduação: Programa de Pós-Graduação em Química - PPGQ
• País: BR
• Palavras-chave em Português: Produtos naturais; Formigas cortadeiras; Nanopartículas; Validação do método; Picramnia bahiensis; Thyrsodium schomburgkianum; Nanoencapsulamento
• Palavras-chave em Inglês: Leaf-cutting ants; Nanoencapsulation; Method validation
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://repositorio.ufscar.br/handle/20.500.14289/6269

The leaf-cutting ants of the genera Atta and Acromyrmex are considered between the most important plagues in agriculture, grassland and reforestation program, due the great amount of leaves cut which the plants are submitted. The factors such as natural resources abundance as food source, scantiness of natural enemies and competitions among others species, promote the attack and, consequently, damages to the plantation, generating serious economic damages, since the density of the nests of leaf-cutting ants can increase 5 to 10 times in relation to a nest in natural environment. The Sapindales order is composed by the families Staphyceaceae, Melianthaceae, Bretschneideraceae, Akaniceae, Sapindaceae, Hippocastanaceae, Aceraceae, Burseraceae, Anacardiaceae, Julianiceae, e Zygophyllaceae. Several compounds with insecticide and antifungal activities have been gotten from these families. In this context, the present work aimed as main objectives the bio-monitored phytochemistry study of Picramnia bahiensis and Thyrsodium schomburgkianum to obtain natural insecticides against Atta sexdens rubropilosa and/or fungicides against the symbiotic fungus Leucoagaricus gongylophorus and, specially, the study of methodologies to apply them to their control. The phytochemistry study of these plants allowed the isolation and identification of 24 compounds, acids and esters that have long chain, anthraquinones, steroids and terpenoids, many of them were identified using the Mass Spectrometry technique (HPLC/ESI-MS/MS), being that the substances 11 and 12 are previously unpublished in literature. Among these substances, chrysophanol, isolated from the roots of P. bahiensis, stand out to have potential insecticide and fungicide activities against the leaf-cutting ants. Furthermore, the study was extended with similar commercial compounds, leading to the compound menadione, also with both potential activities. This fact led to development of formulations through the nanoencapsulation process in order to, besides to obtain highly active compounds, develop an application methodology of them, thus providing an insecticide and fungicide that is viable to use in the leaf-cutting ants control. Therefore, these insecticides have been nanoformulated first time in the literature by the nanoencapsulation technique, evaluating properties such as, for example, the delay activity compared to the free compounds, increasing their effectiveness. Additionally, the analytical method was validated via HPLC, following the ANVISA rules, aiming, mainly, reliability of the quantification results for comparison with traditional standards of baits in the market.