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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 arvens...

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.

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 spe...

The objective of the present work was to determine the effects of colored shading on the density of glandular and tectorial trichomes, and on the yield, productivity and composition of the essential oil of Ocimum selloi Benth. Plants were cultivated for 90 days under full sunlight or under ChromatiNet 50% red or blue netting. The highest density of glandular trichomes was observed in plants that had received full sunlight. None of the light treatments altered the yield of oil, although productivity was higher in plants grown under full sunlight by virtue of the greater leaf biomass that accumulated under such conditions. The compositions of the oils varied according to the quality of light. Although the qualitative profiles of the oils of plants grown under full sunlight or red shading were similar, that obtained from plants grown under blue shading presented a larger number of constituents. The highest level of methyl chavicol (93.2%), the major component of the oil, was observed in plants grown under full sunlight.