Extração de compostos bioativos de folhas de Vernonia amygdalina Delile utilizando dióxido de carbono em condições supercríticas

• Ano de defesa: 2015
• Autor(a) principal: Costa, Fabíola Medeiros da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; BR; Programa de Pós-graduação em Engenharia Química; Engenharias; UFU
• Palavras-chave em Português: Vernonia Amygdalina Delile; Extração supercrítica; Atividade antioxidante; Boldo; Extração (Química); Compostos bioativos; Antioxidantes; Supercritical extraction; Antioxidant activity; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: https://repositorio.ufu.br/handle/123456789/15262; https://doi.org/10.14393/ufu.di.2015.362

The species Vernonia amygdalina Delile is known in the Brazilian regions as boldo, boldo-bahiano, boldo-goiano, alumã, figatil, heparém e árvore-do-pinguço. It is used in folk medicine for the treatment and control of over twenty diseases. Besides being used in human medicine, it is also associated with veterinary and zoofarmacognosy medicine. Considering the diseases that are routinely treated with the plant, it can be verified the use of the leaves against diseases of the gastrointestinal system such as diarrhea, constipation, stomach pain, intestinal worms and bacterial infections. The application of supercritical fluid technology for the extraction of bioactive compounds of this type may be attractive due to the low operating temperature and extracts of high purity. In this context, the aim of this study was to evaluate the overall efficiency of extraction, antioxidant activity and identify the phytochemical constituents of the extracts obtained with pressurized CO2 from Vernonia amygdalina Delile under variation of the parameters pressure, temperature and pre-extraction time and compare them with the extracts obtained by the conventional method Soxhlet using hexane, dichloromethane and ethanol. The supercritical extraction occurred at temperatures of 40, 50 and 60 °C and at pressures of 100, 150, 200, 250 bar. Tests of antioxidant activity were performed. The supercritical extracts of the plant showed the overall yield of 0.78% to 1.48% for 30 min of pre-extraction time, and 0.71% to 1.39% for 60 min. The extraction condition which favors the highest yield for the dry leaves was 60 °C and 250.0 bar. It was possible to identify some major components in species such as palmitic acid, phytol, 9,12-octadecadienoic acid, α-linolenic acid and octadecanoic acid. However, it was not possible to identify various components with high concentration in relation to percentage of area, so many components that are present in the leaves of the species still are in research phase. Furthermore, the material tested showed low antioxidant exhibiting EC50 values ranging from 622.62 to 937.88 μg/mL. Thus, the supercritical extraction tends to be a better method than the extraction to obtain bioactive compounds from Vernonia amygdalina Delile used to develop drugs based on natural products, because of several advantages, such as non-polluting, odorless and leaving no residue in the extract, among others.