Gabriel Fernandes Pauletti

Physico-chemical evaluation of Rosmarinus officinalis L. essential oils

Dezenove amostras de Rosmarinus officinalis foram extraidas por destilacao por arraste a vapor em uma planta piloto e os oleos essenciais foram avaliados quanto a composicao quimica e caracteristicas fisico-quimicas. Os rendimentos de oleo essencial variaram de 0,37% (media de 1999) a 0,49% (media de 1998). Vinte componentes foram identificados nos oleos essenciais. Os componentes majoritarios foram a-pineno (40,55 a 45,10%), 1,8-cineol (17,40 a 19,35%), canfeno (4,73 a 6,06%) e verbenona (2,32 a 3,86%). A media por safra dos parâmetros fisico-quimicos avaliados resultaram em 0,8887g/cm3 para densidade especifica, 1,4689 para indice de refracao e +11,82o para rotacao optica, sendo que as variacoes encontradas para os parâmetros quimicos e fisico-quimicos dos oleos essenciais nao variaram significativamente em funcao do ano de producao.

Chemical characterization and antimicrobial activity of essential oils of salvia L. species

In this work, the essential oils of S. officinalis, S. sclarea, S. lavandulifolia and S. triloba were chemically analyzed by gas chromatography coupled to a mass spectrometry detector (GC/MSD), and their antimicrobial activity was tested against 10 microorganisms using the disk diffusion method and the Minimum Inhibitory Concentration (MIC) technique. The following major compounds were identified in the essential oils: α - and β-thujone, camphor and 1,8-cineole, except in S. sclarea, where linalool, linalyl acetate and α-terpineol were the major constituents. The antimicrobial activity showed significant differences (p < 0.05) only when obtained by the MIC method. Gram-positive microorganisms presented larger sensitivity for the essential oils. The lowest MIC was observed when Staphylococcus aureus was exposed to 2.31 mg.mL-1 of S. lavandulifolia essential oil, while the highest MIC value was obtained when Shigella flexneri was exposed to 9.25 mg.mL-1 of the same essential oil, thus demonstrating that this essential oil may be effective as a bacteriostatic agent against Gram-positive microorganisms.

Genetic variation among South Brazilian accessions of Lippia alba Mill. (Verbenaceae) detected by ISSR and RAPD markers

Twenty-seven accessions of Lippia alba Mill. collected in Rio Grande do Sul state, Brazil, were analysed by ISSR and RAPD markers to evaluate their genetic variability and relationships. Six ISSR primers and four RAPD primers generated 120 amplified fragments, most of which were polymorphics. The overall genetic variability among accessions was very high when compared with other plant species. The hierarchical analysis of molecular data (UPGMA) showed low relationship between accessions, and no grouping between accessions of the same chemotype. Canonical functions allowed identifying some variables related with the chemical characteristics of the essential oils. Both ISSR and RAPD markers were efficient to address the genetic diversity of L. alba, and may contribute to the conservation and breeding of this increasingly important aromatic and medicinal species.

Análise de taninos totais em plantas aromáticas e medicinais cultivadas no Nordeste do Rio Grande do Sul

Tannins are polyphenolic compounds present in plants which are also found in foods and beverages. They are specially used by pharmaceutical, food, leather and rubber industries, and also for water treatment. Considering the significance of this group of compounds, several of aromatic and medicinal plants cultivated in Northern Rio Grande do Sul State, Brazil, were tested for their total tannin content. Angelica archangelica , Cinnamomun camphora var. linaloolifera fugita , Cymbopogon citratus, Lavandula dentata , Lippia alba, Rosmarinus officinalis and Thymus vulgaris were analysed and compared with Acacia mearnsii (black wattle) which is industrially used for tannin extraction. The extraction procedure was made by macerating the plants in methanol, and the quantification was done using Folin Denis reagent and spectrophotometry. By using a calibration curve (% tannic acid equivalent) the total tannin contents range from 0.01% ( Cymbopogom citratus ) to 18.9% ( Lippia alba ).

Antioxidant properties of essential oils from Mentha species evidenced by electrochemical methods

The antioxidant capacity of essential oils of Mentha spicata L., Mentha x gentilis L., Mentha crispa L., Mentha piperita L. and Mentha x piperita L. was determined by using differential pulse voltammetry. This assay was based on the reduction in the limiting current value of the oxygen electroreduction, which was used to calculate the antioxidant capacity (K) of these species. The species M. x gentilis L. had the highest K value. Cyclic voltammetry experiments confirmed the interaction between the electrode surface and the active compounds present in the essential oils. A simple electrochemical method for determining the ability of active compounds to chelate Fe (II) is proposed.

Morphological characterisation and agronomical parameters of different species of Salvia sp. (Lamiaceae)

The aim of this work is to assess the morphological characteristics and parameters of biomass production, such as fresh and dry matter weight (FMW and DMW, g/plant), yield of dry matter (YDM) in terms of ton/ha, essential oil content (EOC, mL/100 g) and yield of essential oils (YEO) expressed as L/ha of the following plants Salvia verbenaca, Salvia argentea, Salvia lavandulifolia, Salvia pratensis, Salvia sclarea, Salvia triloba and Salvia officinalis. Except for Salvia argentea (S2) all other species have adapted to the south Brazilian climate conditions, with morphological differences among the species evaluated. In terms of DMW and YDM, S. officinalis was found to be the most productive species with 445.83 g/plant and 11.14 ton/ha. The higher essential oil content and yield was observed for S. officinalis, affording 1.99 mL/100 g and 221.74 L/ha, respectively. Chemical characterisation of the essential oils obtained from hydrodistillation was performed through GC and GC/MSD analyses, which revealed for most of the species studied, α e β-thujone, camphor and 1,8-cineole as major compounds, apart from S. sclarea, for which linalool, linalyl acetate and α-terpineol were the major components.

Use of palmae wax hydrocarbon fractions as chemotaxonomical markers in Butia and Syagrus

The wax hydrocarbon fractions of native Butia and Syagrus species collected from Palms in different regions of the of Rio Grande do Sul state (Brazil) and in Rocha (Uruguay) were analyzed to evaluate their potential as chemotaxonomic markers. The wax was extracted with chloroform and the resulting wax was fractionated by preparative TLC. The hydrocarbon fractions were analyzed by GC-MS. Statistical analyses were completed with the Statistica 5.0 program. The total crude wax yields averaged 0.31% w.w-1 dried leaves for Butia samples and 0.28% for Syagrus samples. The linear hydrocarbons represented on average 15% of the total waxes in the case of Butia samples and 13.7% in Syagrus samples. Hentriacontane and triacontane were the main components of all samples. The comparison of the means showed significant differences among Butia and Syagrus samples, and amongst Butia samples collected in different localities. In the case of the Syagrus collections no consistent groupings could be made. In the case of Butia samples the formation of three groupings could be observed, which were consistent with the species described for their geographical distribution. These results are discussed in the paper.

In vitro antifungal activity of four chemotypes of Lippia alba (Verbenaceae) essential oils against Alternaria solani (Pleosporeaceae) isolates

Several volatile natural compounds produced by plant secondary metabolism have been proven to present antimicrobial action, enabling their use in phytopathogen control. They also present low environmental impact when compared to conventional pesticides. Essential oils contain these compounds and can be found in several plant species, such as Lippia alba (Mill.) N.E. Brown (Verbenaceae). Essential oils of four chemotypes of L. alba, characterized by their major compounds, namely camphor, citral, linalool and camphor/1,8-cineole, were tested against the phytopathogen Alternaria solani Sorauer (Pleosporaceae), which causes early blight on tomatoes and is responsible for great economic losses regarding production. Essential oils antifungal action was tested in vitro using potato dextrose agar medium with essential oil concentrations at 0.1, 0.5, 1.0, 1.5 and 2.0 µL mL-1. The chemotype that had the best performance was citral, showing significant inhibition compared to the others, starting at the 0.5 µL mL-1 concentration. The essential oil belonging to the linalool chemotype was efficient starting at the 1.5 µL mL-1 concentration. Conversely, the camphor chemotype did not show any action against the phytopathogen. Moreover, the essential oils had no remarkable effect on tomato germination and growth. In conclusion, these essential oils presented fungicidal action against A. solani.

Effect of different liming levels on the biomass production and essential oil extraction yield of Cunila galioides Benth

Poejo is an aromatic and medicinal plant native to highland areas of south Brazil, in acid soils with high Al3+ concentration. The main objective of the present work was to evaluate the effect of liming on the extraction yield of essential oil of three chemotypes of poejo (Cunila galioides Benth). For this purpose, the experiments were performed in a greenhouse, using 8-litre pots. The treatments were four dosages of limestone (0, 3.15, 12.5, and 25 g.L(-1)) and a completely random experimental design was used, with four replications and three chemotypes, set up in a 3 × 4 factorial arrangement. The parameters evaluated were dry weight of aerial parts, essential oil content and chemical composition of essential oil. Results showed that liming affects the biomass production, essential oil yield and chemical composition, with cross interaction verified between chemotype and limestone dosage. For the higher dosage lower biomass production, lower yield of essential oil as well as the lowest content of citral (citral chemotype) and limonene (menthene chemotype) was observed. In the ocimene chemotype, no liming influence was observed on the essential oil yield and on the content of major compounds. The dosage of 3.15 g.L(-1) can be considered the best limestone dosage for the production of poejo for the experimental conditions evaluated.

Fractioning of orange (Citrus sinensis L.) essential oil using vacuum fractional distillation

ABSTRACT Citrus essential oil has many uses in food, cosmetics, and pharmaceuticals industries, especially the minor compounds present in the oil. This work aimed to evaluate the distillation patterns of the components of the peel essential oil of Citrus sinensis using vacuum fractional distillation. The performed tests show that the separation of the compounds occurs with the leaving of the lighter terpenes, followed by the heavier terpenes and part of the oxygenated functions. Most of the oxygenated functions remained in the bottom of the column, being concentrated in this fraction. Many trace compounds were found in the bottom products. The limonene mass percentage reduced from 96.68% to 52.81% in the bottom products. Linalool had its mass percentage increased from 0.37% in the raw oil to 4.22% in the bottom. It was also observed in the operation conditions of the column (10 kPa and 70°C), there was no evidence of thermal degradation of the raw oil, neither of the obtained fractions during the process.