Larissa Corrêa do Bomfim Costa

Histochemistry, content and chemical composition of essential oil in different organs of Alpinia zerumbet

Alpinia zerumbet is a medicinal plant from Asian origin used in folk medicine for the treatment of hypertension, which effect is attributed to terpinen-4-ol, the major component of the essential oil. The objective of this work was to identify the essential oil secretory structures in the leaf, flower, root and rhizome of this plant, and analyze the content and the chemical composition of the oil in the different organs of the plant. Sections were subjected to histochemical test with Nadi reagent for in situ localization of secretion. The essential oil extraction was performed by hydrodistillation in a Clevenger apparatus and the compounds were identified in CG-EM/FID. The histochemical test was positive for terpenoids, confirming the presence of essential oil stored in secretory structures named oils cells present in all analyzed organs. The higher essential oil content was found on the leaf (0.30%), while the petal and the rhizome presented content of 0.10% and 0.06%, respectively. It was not possible to determine essential oil content of the root due to the low amount of biomass produced. There were qualitative and quantitative differences in the chemical composition of the essential oil in the different plant organs, but the major constituent in all of them was the terpinen-4-ol, followed by 1,8 cineol in the leaf and by the α-terpineol in the flower and rhizome.

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.

Anatomia e ultraestrutura foliar de Ocimum gratissimum sob diferentes níveis de radiação luminosa

Plant species are able to adjust their physiological, anatomical and ultrastructural characteristics to changes in environmental factors, such as the availability of incident light. The objective of this study was to evaluate the influence of different light radiation levels on leaf anatomy and ultrastructure in plants of Ocimum gratissimum L. (Lamiaceae). Plants were grown for 93 days in four levels photosynthetic active radiation (FAR): 20, 11, 7 and 4mol m-2 d-1. The increase of light intensity resulted in increase of palisade and spongy parenchyma thickness and leaf blade. However, epidermal thickness was not changed. Regarding the ultrastructural aspects, there was an increase in the size of the chloroplasts and starch granules. However, there was an increase of the stacking of the thylakoids with reducing light intensity. Anatomical and ultrastructural changes confirm the phenotypic plasticity of this species as a function of changes in light intensity.

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.

In vitro antifungal activity of Ocimum selloi essential oil and methylchavicol against phytopathogenic fungi

The ef ficacy of Ocimum selloi essential oil was evaluated for controlling the growth of mycelia and spores germination Moniliophthora perniciosa. Six compounds (99.89%) of the total oil were identified by GC-MS, of which methyl chavicol, methyl eugenol, �� -caryophyllene, germacrene-D, bicyclogermacrene and spathulenol. Essential oil was tested for anti- fungal activity, which was determined by disc diffusion and minimum inhibitory concentration (MIC) determination methods. Application of the oil reduced mycelial growth in a dose dependent manner, with maximum inhibition being observed at concentration of 1,000 ppm. Such antifungal activity could be attributed to methyl chavicol since the pure compound was shown to be similarly effective against Moniliophthora perniciosa at 1,000 ppm. The oil when applied at a concentration of 1,000 ppm, reduced the spore germination of Colletotrichum gloeosporioides and M. perniciosa by 93 and 87%, respectively, but had no effect on the Alternaria alternata. It is concluded that the oil from O. selloi and its major constituent, methyl chavicol, are efficient in inhibiting M. perniciosa, but less effective against C. gloeosporioides and A. alternata. The results obtained from this work may contribute to the development of alternative anti-fungal agents to protect the cacao crop from fungal disease.

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.

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.