RESUMO
Candida species are the main fungal agents causing infectious conditions in hospital patients. The development of new drugs with antifungal potential, increased efficacy, and reduced toxicity is essential to face the challenge of fungal resistance to standard treatments. The aim of this study is to evaluate the in vitro antifungal effects of two crude extracts of Crinum americanum L., a rich alkaloid fraction and lycorine alkaloid, on the Candida species. As such, we used a disk diffusion susceptibility test, determined the minimum inhibitory concentration (MIC), and characterized the components of the extracts using Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI FT-ICR MS). The extracts were found to have antifungal activity against various Candida species. The chemical characterization of the extracts indicated the presence of alkaloids such as lycorine and crinine. The Amaryllidaceae family has a promising antifungal potential. Furthermore, it was found that the alkaloid lycorine directly contributes to the effects that were observed for the extracts and fraction of C. americanum.
Assuntos
Alcaloides , Alcaloides de Amaryllidaceae , Amaryllidaceae , Crinum , Alcaloides/química , Alcaloides/farmacologia , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Candida , Crinum/química , Humanos , Fenantridinas , Extratos Vegetais/química , Extratos Vegetais/farmacologiaRESUMO
O uso prolongado torna os herbicidas tradicionais cada vez menos eficientes no combate às plantas daninhas. O uso de substâncias naturais extraídas das plantas é uma alternativa eficiente e menos agressiva ao meio ambiente. Os aleloquímicos de muitas espécies são possíveis matérias primas para o desenvolvimento de herbicidas orgânicos. Um dos principais problemas encontrados para a produção desses herbicidas é a obtenção de material botânico em quantidade comercial. Melhorar as técnicas de extração é um passo importante, uma vez que reduz a quantidade de matéria prima necessária. Nesse trabalho foram testados diversos tipos de extrações aquosas de folhas secas de Crinum americanumL., uma Amaryllidaceae com forte potencial alelopático. O tempo de extração é pouco importante para o potencial alelopático do extrato. Por outro lado, temperaturas de extração de 40 e 60oC levaram à produção de extratos que inibiram mais eficientemente a germinação. É possível aumentar o potencial alelopático dos extratos utilizando o material vegetal em pó mais de uma vez.
The long-term use reduces the efficiency of the traditional herbicides. The use of plant-extracted natural substances is an alternative more efficient and less aggressive to the environment. The allelochemicals of several species are considered to be possible plants for developing an organic herbicide. One of the major problems in this sense is obtaining botanical material in commercial quantities. Improving the extraction techniques is an important step, once it reduces the amount of botanical material needed. In this survey was tested several methods of aqueous extractions of dried leaves of Crinum americanum L., an Amaryllidaceae with strong allelopathic properties. The time of extraction is not important for the allelopathic potential of the extracts. On the other hand, when the temperature during extraction was 40 e 60oC, leaded to extracts with stronger allelopathic potential. It is possible to improve the allelopathic potential using the filtered matter more than once.
Assuntos
Feromônios , Crinum , Alelopatia , HerbicidasRESUMO
The alkaloids lycorine, 1-O-acetyllycorine and ismine were isolated from the basic dichloromethane-soluble fraction of Crinum x powellii "Albu m" bulbs. The alkaloid structures were established by physical and spectroscopic analyses, including 1D NMR techniques and GC-MS analysis. The three alkaloids are reported for the first time for this hybrid. Additionally, the three alkaloids isolated were tested against a mechanism-based bioassay utilizing genetically engineered mutants of the yeast Saccharomyces cerevisiae strains RAD+, RAD52Y and RS321 where lycorine was the only alkaloid that displayed moderate topoisomerase I inhibitory activity.