Aline Machado Lucas

Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE) to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa), whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa). The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves.

Determination of antibacterial activity of vacuum distillation fractions of lemongrass essential oil

Essential oils are natural substances composed of terpenoids and phenylpropanoid molecules that have many biological activities. Because of their activity, essential oils are widely used in foods, cosmetics, and pharmaceutical products, but new applications of such mixtures are still dependent on separation processes that are able to produce compounds with specific standardized and reproducible compositions. This work studies the fractionation of lemongrass essential oil by vacuum distillation with the goal of obtaining an antimicrobial fraction that acts against Salmonella choleraesuis, Pseudomonas aeruginosa and Staphylococcus aureus. The samples were analyzed by gas chromatography–mass spectrometry and evaluated for antimicrobial activity using the indirect bioautography method and minimum inhibitory concentrations. Vacuum distillation was found to be an efficient method for obtaining distinct fractions with increased antimicrobial activity. The fractions that showed the best response against the three microorganisms tested were F3b, F3a1, F2, F3a2 and F1, with the most effective being F3a2, which also presented the highest yield.

Influence of essential oil fractionation by vacuum distillation on acaricidal activity against the cattle tick

The aim of this work was to study the influence of essential oil fractionation on acaricidal activity against the cattle tick Rhipicephalus (Boophilus) microplus. The citronella (Cymbopogon winterianus J.) and pepper tree (Schinus molle L.) essential oils were fractionated by vacuum distillation yielding fractions that were analyzed by the GC/MS. Laboratory tests were carried out to determine the effect of the total essential oil and fractions on larvae of the cattle tick R. (B.) microplus. The fractions 04 and 05 of the C. winterianus essential oil were the most active showing LC50 values of 1.20 and 1.34 μL/mL, respectively. The LC50 of the total oil was 3.30 μL/mL while the effect of the fractions 01, 02 and 03 was less pronounced, with LC50 values of 4.37, 4.24 and 3.49 μL/mL, respectively. The fraction 03 of the S. molle essential oil was the most active showing LC50 value of 8.80 μL/mL while the fractions 01 and 02 did not show toxic effects on the larvae.

Recent Findings in the Chemistry of Odorants from Four Baccharis Species and Their Impact as Chemical Markers

Baccharis is a widespread genus belonging to the Asteraceae family that includes almost 400 species exclusively from the Americas. Even when studied in detail, the taxonomic classification among species from this genus is not yet fully defined. Within the framework of our study of the volatile composition of the Baccharis genus, four species (B. trimera, B. milleflora, B. tridentata, and B. uncinella) were collected from the ‘Campos de Cima da Serra’ highlands of the Brazilian state of Rio Grande do Sul. The aerial parts were dried and extracted by the simultaneous distillation extraction (SDE) procedure. This is the first time that SDE has been applied to obtain and compare the volatile‐extract composition in the Baccharis genus. Characterization of the volatile extracts allowed the identification of 180 peaks with many coeluting components; these latter being detailed for the first time for this genus. The multivariate statistical analyses allowed separating the volatile extracts of the four populations of Baccharis into two separate groups. The first one included the B. milleflora, B. trimera, and B. uncinella volatile extracts. The three species showed a high degree of similarity in their volatile composition, which was characterized by the presence of high contents of sesquiterpene compounds, in particular of spathulenol. The second group comprised the extract of B. tridentata, which contained α‐pinene, β‐pinene, limonene, and (E)‐β‐ocimene in high amounts.

Mathematical Modeling of Essential Oil Extraction by Steam Distillation for Native Plants from Southern Brazil

Abstract In this study, a desorption model to predict the essential oil extraction curves and global yield versus time was performed for extraction by steam distillation of three native plants of southern Brazil (Schinus molle L., Drimys angustifolia Miers., and Calyptranthes grandifolia O. Berg). The model assumed that the extractable materials were initially available uniformly in the vegetal matrix and adsorbed on the internal microstructures. The volatile extracts were obtained by steam distillation and the chemical composition was determined. The essential oil yields (w/w) were 0.4 %, 0.3 %, and 0.2 %, respectively, for S. molle, D. angustifolia, and C. grandifolia, and the major compounds identified by CG-MS were α-pinene, sabinene, bicyclogermacrene and spathulenol for all the plants here investigated. The desorption model fitted very well the overall extraction curves.

Polyprenylated benzophenone-enriched extracts obtained using SC–CO2 from the dry ethanolic extract of Brazilian red propolis

ABSTRACT Red propolis is a well-known potent antimicrobial source because of its various bioactive compounds. This work aims to submit a sample of Brazilian red propolis to supercritical CO2 extraction, with subsequent chemical characterisation by HPLC and UHPLC–MS, and to evaluate the antifungal activity against three strains of Candida glabrata. The method proved to be selective for the extraction of benzophenones. The results demonstrated a correlation between the presence of benzophenones and antifungal activity. The supercritical extract that seems to be the richest in benzophenones was the one obtained with a pressure of 300 bar and was the most active against the C. glabrata strains. Abbreviations: SFE, Supercritical Fluid Extraction; MIC, Minimal Inhibitory Concentration; SC, Supercritical; BZP, benzophenones

Comparison of genetically engineered (GE) and non-GE Eucalyptus trees using secondary metabolites obtained by steam distillation

Abstract The genus Eucalyptus is composed of hundreds of species with multiple important uses, making it one of the most valuable forest trees around the world. The genetic improvement of Eucalytpus has been studied especially to improve timber production, wood quality and disease resistance. One of the current approaches to improve Eucalyptus tree species is genetic engineering, and it is a common sense that transgenic plants must be submitted to detailed environmental and health risk assessments in order to guarantee their biosafety for future commercial release. This work aimed to characterize and compare the essential oil composition of leaves from genetically engineered (GE) and non-GE Eucalyptus trees of the hybrid E. grandis x E. urophylla employed in cellulose pulp and paper production. Our results allowed us to conclude that no significant differences in the content or chemical composition of leaf essential oils exist between GE and non-GE Eucalyptus trees.

Chromenes from Ageratum conyzoides: Steam distillation, supercritical extraction, and mathematical modeling

ABSTRACT The chromenes extraction processes from Ageratum conyzoides by steam distillation and supercritical fluid extraction (SFE) were studied. Essential oil was extracted by saturated steam at 1.0 to 2.0 bar and the SFE was performed at 40ºC and 90 to 200 bar to obtain non-volatile extracts. The essential oil presented two major compounds—precocene I (28.24%) and precocene II (28.55%). At 90 bar, the SFE resulted in higher yield and selectivity for precocene I and II (65.06%). The yield of chromenes varied according to pressure of SFE; however, this behavior was not observed in extracts obtained by steam distillation.

Environmental and health risk assessments of genetically modified eucalypts in Brazil

Motivated by the Brazilian Ministry of Agriculture, Farming and Supply (MAPA), we created in 2009 the “Collaborating Center in Agriculture Defense Relative to the Biosafety of Genetically Modified Eucalypts” (Project “CDA Eucalyptus”) in order to collect information and conduct research to assess the biosafety of GM eucalypts in the Brazilian context. The Normative Resolution Nr. 5 of the National Biosafety Technical Commission (CTNBio) is the official document presenting all information needed to propose the commercial release of GMOs in Brazil. Based on this document and along with the personnel of the Suzano Paper & Cellulose Co., we conducted a series of experiments with GM and non-GM eucalypts planted in a test field in the state of Sao Paulo to start collecting the necessary information. Two independent groups of transgenic plants, harboring two different transgene constructions along with non-GM control plants are being assayed. The genetic traits, the identity or names of the transgenes as well as the identity of each tree individual will not be revealed due to intellectual property request still pending. Each group of plants was represented by four independent events in triplicates (2 groups x 4 events x 3 clonal trees + 3 non-GM clonal trees), therefore totaling 27 individuals under analysis. Samples were identified by random numbers and all assays were conducted in a simple-blind or a double-blind fashion. Tests concluded until now included (i) the detection of transgene regulatory sequences in purified DNA samples by conventional PCR and RT-qPCR, confirming the expected sampling conducted; (ii) extraction, chemical characterization and analysis of the antifungal effects of essential (volatile) oils extracted from leaves; (iii) pollen germination in vitro; (iv) flower morphology; (v) seed production; (vi) initial seedling development; (vii) leaf allelopathy; (viii) measurements of total phenolic compounds in leaves and roots; and (ix) effects of leaf extracts on the viability of human colon cells. All results obtained from experiments (ii) to (ix) revealed no statistical differences between GM- and non-GM-derived samples. A second round of experiments will be conducted to confirm these results. Proteomic and transcriptomic profiling of GM and non-GM trees are under analysis, as well as a series of experiments that include the chemical, nutritional and biological analysis of honey samples derived from bee hives located in fields of GM versus non-GM plants; and bee (Apis mellifera) population dynamics.