Anxiolytic-like activity and GC-MS analysis of (R)-(+)-limonene fragrance, a natural compound found in foods and plants.

The traditional use of essential oils in aromatherapy has offered numerous health benefits. However, few scientific studies have been conducted with these oils to confirm their therapeutic efficacy. (+)-Limonene is a chemical constituent of various bioactive essential oils. The present study reports on the anxiolytic-like effects of (+)-limonene in an elevated maze model of anxiety in mice. At concentrations of 0.5% and 1.0%, (+)-limonene, administered to mice by inhalation, significantly modified all the parameters evaluated in the elevated plus maze test. The pharmacological effect of inhaled (+)-limonene (1%) was not blocked by flumazenil. Analysis of (+)-limonene using gas chromatography-mass spectrometry (GC-MS) showed its volatility to be high. These data suggest possible connections between the volatility of (+)-limonene and its anxiolytic-like effect on the parameters evaluated in the elevated plus maze test. The data indicate that (+)-limonene could be used in aromatherapy as an antianxiety agent.

Usefulness of pyrolysis coupled to gas chromatography/mass spectrometry for evaluating the reproducibility of commercial samples of Cymbopogon citratus Stapf., Poaceae / Utilidade da técnica de pirólise acoplada a cromatografia gasosa/espectrometria de massas na avaliação da uniformidade de conteúdo de amostras comerciais de Cymbopogon citratus Stapf

The usefulness of pyrolysis coupled to gas chromatography/mass spectrometry (Py-GC/MS) to evaluate the identity and reproducibility of different brands and batches of commercially available samples of Cymbopogon citratus Stapf (sold as tea) was investigated. Samples of the vegetable material were extracted using hexane and the extract was pyrolysed at 450 ºC using a vertical microfurnace pyrolyser interfaced directly with a gas chromatograph/mass spectrometer operated using electron impact ionization at 70 eV. The relative peak areas of the different compounds identified on the pyrograms were used for multivariate data analysis using principal component analysis (PCA) and hierarchical cluster analysis (HCA) techniques. Principal component analysis of pyrolysis data from samples of different brands was able to represent 84.7 percent of the total variability within the first two principal components, and led to the correct classification of the samples tested. The method was also able to reveal important differences between samples when different batches of the same brand were compared.

A utilidade da técnica de pirólise acoplada à cromatografia à gás/espectrometria de massas (Py-GC/MS) na avaliação da identidade e reprodutibilidade de diferentes marcas e lotes de amostras comerciais de Cymbopogon citratus Stapf. (comercializado como chá) foi investigada. Amostras do material vegetal foram extraídas com hexano e o extrato foi diretamente pirolisado a 450 ºC utilizando um pirolisador de microforno vertical, interfaciado diretamente com um cromatógrafo à gás/espectrômetro de massas, operado utilizando ionização por impacto eletrônico a 70 eV. As áreas relatives dos picos de interesse identificados nos pirogramas foram utilizadas para análise estatística multivariada, com análise de componentes principais e análise hierárquica de agrupamentos. A análise de components principais dos dados de pirólise foi capaz de representar 84.7 por cento da variabilidade total nos dois primeiros componentes calculados e levou a correta classificação das amostras testadas. O método foi capaz de revelar diferenças importantes entre amostras, quando diferentes lotes da mesma marca foram comparados.