Rosilene Aparecida de Oliveira

Determinação do tempo de hidrodestilação e do horário de colheita no óleo essencial de menta

The extraction time and harvest moment are important information in the study of herbs. They can maximize the efficiency of the extraction process and the amount of essential oil produced. The objective of this study was to determine the time of hydrodistillation and evaluate the effect of the harvest moment on the content, yield and chemical composition of essential oil of Mentha x piperita var citrata. The treatments consisted of four extraction times (30, 60, 90 and 120 min) and five harvest moments (9:00, 11:00, 13:00, 15:00 and 17:00 hours) with four replications arranged in a randomized design. After 60 minutes of hydrodistillation in Clevenger apparatus the volume extracted stabilized. In relation to the harvest moment, a significant variation was observed in the essential oil content throughout the day, the highest value (1.33%) being found in samples taken at 13:00h. Variation in the chemical composition of essential oil was also noticed and higher contents of α-fenchol and cis-myrtanol were verified in the morning and in the afternoon, respectively.

Light intensity on growth, leaf micromorphology and essential oil production of Ocimum gratissimum

Light conditions can promote the growth and development of plants and contribute to increase the essential oil production of commercially cultivated medicinal and aromatic species. In view of the great importance of Ocimum gratissimum L., Lamiaceae, as an aromatic plant, the objective of this work was to determine the effect of light intensities (approximately 4, 7, 11 and 20 mol m-2 d-1) on growth, foliar micromorphology, essential oil content, yield and chemical composition of O. gratissimum. Biomass production of different organs, root:shoot ratio and leaf mass per area were found to linearly increase with increased light availability, whereas stem dry matter fraction, number of leaves, leaf area and plant height have increased up to 10 mol m-2 d-1 and decreased from this value. The tector trichomes density increased with increased light availability, but there was no effect of light treatments on the glandular trichomes density and essential oil content. Regardless of the light level, the major component of the essential oil was eugenol. The essential oil yield per plant increased linearly with light intensity as a direct effect of increased leaf biomass under similar conditions.

Essential oils composition of four Piper species from Brazil

The Piper L. genus has a great variety of commercially, pharmacologically and biologically interesting species. The present study focused on essential oils extracted by means of the hydrodistillation from dry leaves of Piper cernuum, Piper glabratum, Piper hispidum and Piper madeiranum. The species supplied essential oil contents of between 0.5% and 0.8%. Gas chromatography–mass spectrometry analyses revealed that the majority of components were -elemene (11.6%) and epi-cubebol (13.1%) for P. cernuum; -caryophyllene (14.6%) and longiborneol (12.0%) for P. glabratum; -pinene (12.0%), khusimene (12.1%) and -cadinene (13.2%) for P. hispidum; -caryophyllene (11.2%) and germacrene D-4-ol (11.1%) for P. madeiranum. The test carried out on the essential oils concerning the Artemia salina L. produced the following values for LC50 200.03 μg/mL (P. cernuum), 45.21 μg/mL (P. glabratum), 404.80 μg/mL (P. hispidum) and 49.64 μg/mL (P. madeiranum).

Influência da idade da planta na produção de óleo essencial de alevante

O teor de oleo essencial e a sua composicao quimica sao caracteristicas geneticas e podem ser influenciados pelo ambiente e pelo estadio de desenvolvimento ou idade da planta. Dessa forma, objetivou-se, com este trabalho, avaliar a influencia da idade da planta sobre a producao e a qualidade do oleo essencial de alevante. O experimento foi conduzido em Ilheus, BA, no periodo de maio a dezembro de 2009. Os tratamentos foram constituidos da colheita, em seis idades da planta (60, 90, 120, 150, 180 e 210 dias apos o transplante), utilizando-se o delineamento inteiramente casualizado, com quatro repeticoes. O oleo essencial foi obtido por hidrodestilacao, em aparelho de Clevenger modificado. A identificacao dos constituintes quimicos foi realizada por cromatografia gasosa acoplada ao espectrometro de massas (CG-EM). O maior teor do oleo essencial (1%) ocorreu aos 120 dias e o maior teor dos compostos majoritarios α-fenchol (49,92%) e cis-mirtanol (30,03%), aos 120 e 150 dias apos o transplante, respectivamente.

Lippia alba morphotypes cidreira and melissa exhibit signifi cant differences in leaf characteristics and essential oil profi le

Lippia alba (Mill.) N.E. Br. ex Britton & P. Wilson, Verbenaceae, is widely used in traditional Brazilian medicine for the treatment of abdominal distress. The species exhibits considerable chemical and morphological diversity, and various chemotypes have been characterized. A comparative study of L. alba, has been carried out of the morphoanatomical characteristics of the leaves and the profiles of the essential oils of the morphotypes cidreira and melissa grown in the Medicinal Plant Garden of the Universidade Estadual de Santa Cruz, Ilheus, Bahia, Brazil. The mean plant height of cidreira was 1.80 m and the stems and branches were fairly erect, while melissa plants were smaller (1.60 m) and presented prostrate stems and branches. Although the leaf of the morphotypes look were similar, the mean values of length, width and area of the leaves of cidreira (respectively, 7.42 cm, 3.32 cm and 17.31 cm2) differed significantly from those of melissa (4.68 cm, 2.35 cm and 7.32 cm2). The morphotypes presented amphistomatic leaves with uniseriate epidermis on both surfaces. The mesophyll was dorsiventral, but in cidreira the palisade parenchyma was biseriate while in melissa it was uniseriate. Simple tector and capitate glandular trichomes were present on the adaxial and abaxial surfaces of the leaf blades of both morphotypes. Six distinct types of glandular trichomes could be distinguished: types I and II were present in both morphotypes, while type III was detected only in cidreira, and types IV to VI were present only in melissa. The two morphotypes also differed with respect to the composition of the essential oil, cidreira produced oil composed mainly of citral, while the oil from melissa was rich in citral, limonene and carvone.

Harvest time and plant age on the content and chemical composition of the essential oil of Alpinia zerumbet

Alpinia zerumbet is an aromatic and medicinal plant rich in essential oil, known as colonia. Essential oils are derived from secondary metabolism and may be a source of raw materials for cosmetic, pharmaceutical, food and perfumery industry. The plant secondary metabolism and biosynthetic activity can vary according to endogenous and exogenous factors to which it is exposed. In this context, in this study we evaluated the influence of harvest time and plant age of Alpinia zerumbet on biomass and essential oil production. For the harvest time experiment the plants of A. zerumbet were harvested at different times (8, 10, 12, 14, 16 and 18 h), using a completely randomized design with four replications. In the plant age experiment the seedlings were propagated by division of rhizomes and grown in a completely randomized design with treatments consisting of four ages (3, 6, 9 and 12 months after transplanting), with seven replications. The extractions of the essential oil were performed by oil hydrodistillation in Clevenger apparatus and chemical analysis by gas chromatography coupled with mass spectrometry (CG-MS). There was an effect of harvest time on the essential oil content with the highest value (0.48%) found at 14:33 h with no change in the chemical composition. In relation to plant age, there was a significant increase in aboveground biomass of plants, accompanied by increases in height, number of shoots, and essential oil content and yield. The major compound terpinen-4-ol was present in higher concentrations in plants harvested between six and nine months old.

Histochemical characterization of secretory ducts and essential oil analysis of Protium species (Burseraceae)

Abstract One feature of the Protium genus is the presence of secretory ducts associated with the phloem. These ducts are characterized by the production of essential oils with different classes of secondary metabolites. In light of this observation, the purpose of this study was to determine which secondary metabolites are present in the secretory ducts of P. aracouchini, P. heptaphyllum, P. icicariba and P. warmingianum using histochemical tests and essential oil chemical analysis. The essential oils are present at different levels and compositions in the four studied species; other metabolites also varied from species to species. Variation was observed among the essential oil classes with oxygenated sesquiterpenes being the most representative class found in the species studied. The major component of all species was caryophyllene oxide; thus, it may be regarded as a genus characteristic. Through the results obtained, characteristics common to all species were defined, enabling the segregation of the species and the use of these commonalities in taxonomic studies of the genus.

Improvement in menthol extraction of fresh leaves of Mentha arvensis by the application of multi-enzymatic extract of Aspergillus niger

Abstract The objective of this study was to optimize the enzymatic pretreatment process of extracting menthol, a major component of the essential oil stored in the trichomes of fresh leaves of Mentha arvensis, by the action of the crude enzymatic extract previously produced by the Aspergillus niger fungus cultivated in cactus pear. Under the experimental conditions of 42 °C, 141 min and 58 mL of enzyme in 442 mL of water, there was an increase of 186.63% in the hydrodistillation yield, which represents an acceptable positive deviation of 12.54% compared to the predicted value of the model obtained by experimental design. Trichome rupture can be confirmed by scanning electron microscopy (SEM) and the chemical structure of the obtained menthol was not modified according to gas chromatography and infrared spectroscopy. The enzymatic pretreatment applied before the hydrodistillation step was successful and proves the potential of the association of biotechnological techniques with a physicochemical process.

Influência da solubilidade de extratos etanólicos em testes com Artemia salina

Tests with the microcrustacean Artemia salina are widely used by researchers of natural products as a quick and easy method applied to biological activity screening of natural products, including crude extracts. Median lethal concentration (LC50) values, obtained by means of the correlation among extract concentration and the quantity of A. salina dead, ≤ . μg mL, were considered as an indicative of biological activity. In this method, plant extracts should be dissolved in saltwater. However, the complete dissolution of samples to be tested is difficult to be reached. Thus, the solubility factor represents a strong interference parameter in determining the LC50 value, affecting the real biological potential evaluation of the nature product. In this context, when complete solubilization of extract is not observed, is herein suggested a methodological adaptation based on the use of DMSO or Tween 80, followed by filtration of the solution, before the in vitro assays. Additionally, the Probit model is recommended to obtain statistically significant values of LC50. Thus, the proposed methodological adaptation enhances the precision of the LC50 results.O teste com o microcrustaceo Artemia salina e amplamente usado por pesquisadores em Produtos Naturais como um metodo facil e rapido de triagem biologica de material vegetal. Valores de Concentracao Letal (CL 50 ), obtidos a partir da correlacao entre concentracao de extrato e quantidades de A. salina mortas, abaixo de 1.000 µg mL -1 e considerada como indicativo de possivel atividade biologica. Nesse processo, extratos vegetais devem ser solubilizados em agua salina, no entanto, dificilmente e observado sua completa solubilizacao. Acreditamos que o fator solubilidade seja um forte interferente para determinar o valor de CL 50 , podendo afetar a indicacao da potencialidade biologica do material vegetal. Neste trabalho propomos uma adaptacao metodologica para conferir maior precisao aos valores de CL 50 . Indicamos o uso de tensoativos DMSO ou Tween 80, seguido de filtracao, quando nao for observado a solubilizacao completa do extrato. Como metodo para determinar o valor de CL 50 sugerimos o modelo estatistico Probit.

Storage conditions of Ocimum gratissimum L. leaves influence the quality of essential oil

Abstract The quality and content of essential oils extracted from medicinal plants can be affected by storage conditions. The present work evaluated the influence of different storage conditions of Ocimum gratissimum leaves on essential oils. The study was conducted in two environments (controlled and natural), in two types of packaging (plastic and paper) during five storage times (0, 3, 6, 9, and 12 months). Also evaluated was the damage caused to the glandular trichomes and the fungal contamination of the stored leaves. For this data set, the study was done using multivariate exploratory analysis PCA, HCA and K-means. Among the environments, the use of paper storage in a natural environment presented a reduction of up to 74.3% in essential oil content and greater damage to the trichomes. The plastic packaging prevented the proliferation of fungi. The best storage condition proved to be a controlled environment from 6 months to 9 months in plastic packaging.