Atividade antibacteriana e análise fitoquímica de Lippia sidoides Cham.

Detalhes bibliográficos
Ano de defesa: 2009
Autor(a) principal: Garcia, Viviane de Oliveira
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Santa Maria
BR
Farmacologia
UFSM
Programa de Pós-Graduação em Ciências Farmacêuticas
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://repositorio.ufsm.br/handle/1/5919
Resumo: Lippia sidoides Cham. is a plant indicated to integrate the Brazilian phytotherapy program of SUS; this species is characterized by its antimicrobial activity due to its amounts of thymol and carvacrol. Other constituents that contribute for this activity are flavonoids and naphtochinones. Aiming to optimize the use of simple galenic preparations obtained from this plant as antimicrobial agent, as well as to find a extraction procedure with environmental friendly characteristics and with good yields, we evaluated seven different extracts. Maceration, extraction by soxhlet, ultrasound-assisted extraction, microwave-assisted extraction and supercritical fluid extraction were compared in relation to the yield of dry extract, time and solvent consumption and antibacterial activity. The extract obtained by soxhlet was more profitable (26.3%), whereas the extract obtained by maceration spent more solvent and also time (30240 min and 2300 ml, respectively). The ultrassonic extraction by bath and horn, one of 130W and another of 750W, furnish extracts with intermediate values in time and solvent consumption (60 min e 125-250 ml), and not presented any advantages in extraction considering the evaluated parameters. The extract obtained by supercritical fluid extraction used CO2 and showed lower values of minimal inhibitory concentration for all bacterial strains tested and in generally it was superior to the other methods against both Gram-negative as Gram-positives. The characterization of the extract with the lowest MIC values was performed by gas chromatography-mass spectrometry (GC-MS), allowing the identification of thymol, carvacrol as major components. Additionally, thymol acetate, Z-cariophyllene, Ecariophyllene, germacrene D and cariophyllene oxide, as well as trace constituents were identified. The supercritical fluid extraction (SFE) performed at 50° C and 150 bar also proved be superior in selectivity for the extraction of the active substances.