Publicação
Plant extracts: isolation, characterization, encapsulation in lipid nanosystems and cytotoxicity in AGS cells
| Resumo: | Plants contain essential products for the maintenance of the cell (lipids, proteins, carbohydrates and nucleic acids) and by-products that come from several biosynthetic pathways. These by-products are named phytochemicals and include phenols, glycosides, alkaloids and terpenoids. Phytochemicals possess interesting potential biological activities, however, some are extremely unstable, which could be a handicap in potential application of these plant extracts. In this work, Phytolacca americana L., Tagete patula L., Cotoneaster horizontalis Decne, Rosmarinus officinalis L. and Aloe barbadensis Miller were chosen for extraction and characterisation of their phytochemicals and also to evaluate their anticancer potential using non-encapsulated and lipid encapsulated extracts. Various spectroscopic and chromatographic techniques have been used for extract composition analysis, namely 1H- and 13C-NMR, HPLC-DAD, HRMS, IR, UV-Vis. Saponins, terpenes, phenolics, carotenoids and anthraquinone type compounds are amongst the phytochemicals present in the extracts. In the case of rosemary, it was possible to isolate and fully identify a single compound, verbenone. All the extracts/fractions from these species have shown toxicity against human adenocarcinoma stomach cells and only the toxicity of extract (after hydrolysis) from pokeweed and verbenone are related to processes leading to cell necrosis. The encapsulation of extract obtained before hydrolysis from pokeweed and of one fraction collected from French marigold have shown high efficiencies up to 98%; however the encapsulation of extract obtained from pokeweed after hydrolysis, has shown a lower efficiency. Overall, the results obtained are interesting and encouraging for further studies. |
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| Autores principais: | Monteiro, Mariana Isabel Cunha Nogueira Almeida |
| Assunto: | Phytochemicals Extraction techniques Biological activity Nanoencapsulation in lipid systems Fitoquímicos Técnicas de extração Atividade biológica Nanoencapsulamento em sistemas lipídicos |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Plants contain essential products for the maintenance of the cell (lipids, proteins, carbohydrates and nucleic acids) and by-products that come from several biosynthetic pathways. These by-products are named phytochemicals and include phenols, glycosides, alkaloids and terpenoids. Phytochemicals possess interesting potential biological activities, however, some are extremely unstable, which could be a handicap in potential application of these plant extracts. In this work, Phytolacca americana L., Tagete patula L., Cotoneaster horizontalis Decne, Rosmarinus officinalis L. and Aloe barbadensis Miller were chosen for extraction and characterisation of their phytochemicals and also to evaluate their anticancer potential using non-encapsulated and lipid encapsulated extracts. Various spectroscopic and chromatographic techniques have been used for extract composition analysis, namely 1H- and 13C-NMR, HPLC-DAD, HRMS, IR, UV-Vis. Saponins, terpenes, phenolics, carotenoids and anthraquinone type compounds are amongst the phytochemicals present in the extracts. In the case of rosemary, it was possible to isolate and fully identify a single compound, verbenone. All the extracts/fractions from these species have shown toxicity against human adenocarcinoma stomach cells and only the toxicity of extract (after hydrolysis) from pokeweed and verbenone are related to processes leading to cell necrosis. The encapsulation of extract obtained before hydrolysis from pokeweed and of one fraction collected from French marigold have shown high efficiencies up to 98%; however the encapsulation of extract obtained from pokeweed after hydrolysis, has shown a lower efficiency. Overall, the results obtained are interesting and encouraging for further studies. |
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