AvaliaÃÃo fungitÃxica e caracterizaÃÃo quÃmica dos Ãleos essenciais e extratos obtidos apÃs diferentes processos de extraÃÃo de Cipà Vick (Tanaecium Nocturnum) e JoÃo Brandim (Piper Piscatorum) / Evaluation of fungitoxic activity and chemical characterization of the essential oils obtained after different processes of extraction of cipà vick (Tanaecium nocturnum) and joÃo-brandim (Piper piscatorum).

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The chemical characterization by IR, GC-MS and GC-FID of essential oils and extracts obtained from Piper piscatorum and Tanaecium nocturnum, plant species native to the state of Acre, by different extraction processes and the evaluation of the toxicity to Aspergillus flavus were performed. The study involved four experiments. In the first, the efficiency of the extraction of the fresh and dried roots of Piper piscatorum was evaluated employing steam distillation and extraction with hot and cold solvents of increasing polarity. The second experiment involved the evaluation of the efficiency of supercritical extraction of the fresh and dried leaves of the same species with CO2 and co-solvents (10 % ethanol and 10 % methanol) at 40 ÂC and 70 ÂC and a pressure of 400 bar. The essential oils obtained by steam distillation of the fresh and dried (30 ÂC and 40ÂC) leaves, stems and roots of Tanaecium nocturnum were characterized chemically in the third experiment. In the fourth experiment, the toxicity of the essential oil from the fresh leaves of Tanaecium nocturnum to Aspergillus flavus isolated from Brazil nuts was evaluated. The prinicipal components identified in the essential oil of Piper piscatorum were selin-11-en-4--ol (40.69%), tetradecanol (26.31%), piperovatine (22.46%) and hydrocarbons (36.43%). The highest yields of extracts were obtained with refluxing polar solvents. The highest concentrations of piperovatine, pipercallosidine and pipercallosine, which are potential anesthetics, were encountered in extracts of fresh roots obtained by hot and cold extractions with ethyl acetate. In the second experiment, the highest yields (% w/w) of extract, piperovatine and pipercallosidine were obtained from fresh leaves of Piper piscatorum extracted with CO2 + ethanol at 40 ÂC. Drying of the material lead to a reduction in the yields of the essential oil and the extracts, except for the assays with CO2, using ethanol as the co-solvent. The principal component identified in these extracts was piperovatine, followed by palmitic acid, pentadecane and pipercallosidine. The treatment caused modifications in the chemical composition of the raw material, especially in the concentrations of the amides. The main compounds encountered in the essential oil of Tanaecium nocturnum were benzaldehyde, benzyl alcohol and mandelonitrile. Drying of the plant material caused loss of the essential oil with modifications in the chemical composition, with emphasis on the elimination (leaves) or reduction (stems and roots) in the mandelonitrile content. Total inhibition of the micelliar growth of Aspergillus flavus during 10 days of incubation was observed at an essential oil concentration of 0.5 L/mL in the contact test and 1.0 L/mL in the fumigation test. This oil inhibited sporulation in both techniques using a concentration of 0.5 L/mL.

ASSUNTO(S)

extratos processes of extraction Ãleo essencial extracts outros essential oil extracts nenhuma abaixo processos de extraÃÃo essential oil

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