Patrícia Fontes Pinheiro

Insecticidal activity of citronella grass essential oil on Frankliniella schultzei and Myzus persicae

The thrips, Frankliniella schultzei, and green peach aphid, Myzus persicae, cause direct damage to plants of economic importance and transmit phytoviruses, causing large economic losses. Chemical constituents of essential oils present a wide range of biological activities. The aim of this work was to evaluate insecticidal activity of essential oil from citronella grass, Cymbopogon winterianus, on F. schultzei and M. persicae. This essential oil was obtained by steam distillation and components were identified by GC/FID and GC/MS. A Potter spray tower was used to spray insects with the essential oil. The major constituents are geraniol (28.62%), citronellal (23.62%) and citronellol (17.10%). Essential oil of C. winterianus at 1% (w v-1) causes mortality in F. schultzei and M. persicae at 34.3% and 96.9%, respectively. The LC50 value for M. persicae was 0.36% and LC90 0.66%. Thus, citronella grass essential oil at 1% (w v-1) is more toxic to M. persicae than F. schultzei. This essential oil shows promise for developing pesticides to manage M. persicae.

Phytotoxicity and Cytotoxicity of Essential Oil from Leaves of Plectranthus amboinicus, Carvacrol, and Thymol in Plant Bioassays.

The essential oil of Plectranthus amboinicus and its chemotypes, carvacrol and thymol, were evaluated on the germination and root and aerial growth of Lactuca sativa and Sorghum bicolor and in acting on the cell cycle of meristematic root cells of L. sativa. The main component found in the oil by analysis in gas chromatography-mass spectrometry and gas chromatography flame ionization detection was carvacrol (88.61% in area). At a concentration of 0.120% (w v(-1)), the oil and its chemotypes retarded or inhibited the germination and decreased root and aerial growth in monocot and dicot species used in the bioassays. In addition, all substances caused changes in the cell cycle of the meristematic cells of L. sativa, with chromosomal alterations occurring from the 0.015% (w v(-1)) concentration. The essential oil of P. amboinicus, carvacrol, and thymol have potential for use as bioherbicides.

Chemical Composition of Essential Oil from Eucalyptus citriodora Leaves and Insecticidal Activity Against Myzus persicae and Frankliniella schultzei

Abstract Essential oils, volatile compounds obtained from plants, provide an alternative approach for controlling agricultural pests due to problems with conventional chemical products, such as insect resistance, environmental issues and human health concerns. This work aimed to extract essential oil from Eucalyptus citriodora to assess its chemical composition and insecticidal activity against the green peach aphid (Myzus persicae) and thrips (Frankliniella schultzei). The essential oil was obtained by hydrodistillation using the Clevenger apparatus and analyzed by gas chromatography with a flame ionization detector and mass spectrometry (GC-FID and GC-MS). A Potter tower was used to spray the insects with the essential oil solutions. The major components found in E. citriodora essential oil were citronellal (29.31 %), geraniol (27.63 %), β-citronellol (14.88 %) and δ-cadinene (6.32 %). Mortality of M. persicae and F. schultzei nymphs were 85.5 % and 34.8 %, respectively, using essential oil at 1 % (w v−1). Estimated values of LC50 (0.40 % w v−1) and LC90 (1.15% w v−1) for M. persicae evidences the potential use of E. citriodora essential oil in controlling this pest.

Biodiesel production from cotton oil using heterogeneous CaO catalysts from eggshells prepared at different calcination temperatures

Abstract Biodiesel is a fuel from vegetable oil or animal fat, and is a promising substitute for petroleum-derived diesel. Transesterification is the most widely used method in biodiesel production. Eggshell is rich in calcium carbonate (CaCO3), and when it is subjected to heat treatment it results in calcium oxide (CaO). CaO from eggshells was prepared at different calcination temperatures, and characterized by X-ray diffraction, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The obtained CaO was used as a catalyst. All catalysts showed good stability and excellent morphology for biodiesel synthesis. Catalytic activity was evaluated by the methyl transesterification reaction of cotton oil for 3 h, 9:1 methanol:oil molar ratio, 3 wt% (catalyst/oil weight ratio) catalyst and 60°C. Biodiesels showed an ester content of 97.83%, 97.23% and 98.08%, obtained from calcined eggshell at 800°C, 900°C and 1000°C, respectively. Biodiesel quality was affected by the acidity of the cation exchange resin. The kinematic viscosity of biodiesel was in accordance with specification, except for the biodiesel obtained from the calcined catalyst at 1000°C. The CaO from eggshells obtained at different calcination temperatures is promising for biodiesel synthesis.

ÓLEOS ESSENCIAIS DE MANJERICÃO E GENGIBRE NA AROMATIZAÇÃO DE AZEITE DE OLIVA

O presente trabalho teve como objetivo aromatizar azeite de oliva com oleos essenciais de manjericao e gengibre e determinar a composicao quimica dos compostos presentes nos respectivos oleos. Os oleos essenciais de manjericao e gengibre foram obtidos por hidrodestilacao e analisados por cromatografia gasosa (CG) e por cromatografia gasosa acoplada a espectrometria de massas (CG-EM). Os azeites de oliva aromatizados foram submetidos a analise sensorial. Os componentes majoritarios determinados para o oleo essencial de manjericao foram o 1,8-cineol (33,63%) e linalol (35,29%). Os seis principais componentes volateis encontrados no oleo essencial de gengibre foram o citral, a mistura de geranial (18,79%) e neral (9,90%), -Amorfeno (10,38%), canfeno (9,98%), -felandreno (9,32%) e E,E-- farneseno (8,83%). Os resultados da analise sensorial revelaram boa aceitacao para os dois azeites formulados, indicando a existencia de um mercado a ser explorado.

Characterization of the Essential Oil of Mastic Tree from Different Biomes and its Phytotoxic Potential on Cobbler’s Pegs

Abstract Schinus terebinthifolius Raddi, popularly known as mastic tree, presents a known healing, anti-inflammatory and antiseptic activities. The study of others biological activities of mastic tree may help to develop natural products less harmful to humans and nature. Thus, the present study aimed to characterize and investigate the activity of the essential oil from fresh leaves of this species, collected in biomes of cerrado and Atlantic Forest of Minas Gerais (Brazil), over the germination of cobbler’s pegs (Bidens pilosa L.). The chemical composition of essential oil varied depending on the biome where the leaves were collected. The major compounds found in the essential oil of mastic tree from Cerrado were trans-caryophyllene (21.9%) and δ-3-carene (18.0%). While the α-pinene (62.9%) and limonene (19.1%) were the major components found in the essential oil of mastic tree collected in the Atlantic Forest. The essential oils showed phytotoxic activity on the development of cobbler’s pegs, there was inhibition of germination, root growth, hypocotyl growth and biomass production, and its effects was higher as the concentration of the oils increased (0.05 w v-1).

CARACTERIZAÇÃO DA MISTURA ÓLEO DE SOJA E GORDURA SUÍNA 1:1 (m m-1) E SEU POTENCIAL NA PRODUÇÃO DE BIODIESEL

O biodiesel no Brasil e obtido, predominantemente, pela reacao de transesterificacao de oleo de soja por via metilica. Buscando encontrar uma maneira em minimizar a quantidade de oleo de soja usado na producao de biodiesel, o objetivo deste trabalho foi averiguar o potencial da mistura de oleo de soja e gordura suina 1:1 (m m-1) para esse fim, para isso foram determinadas suas propriedades fisico-quimicas e sua composicao por cromatografia gasosa acoplada a detector de chamas (CG-DIC). A referida mistura apresentou umidade, indice de acidez, indice de iodo, massa especifica, ponto de fusao, indice de saponificacao e composicao de acidos graxos dentro do desejado para materia-prima na producao de biodiesel, sendo encontrados 20,84% de palmitico, 8,32% de estearico, 30,55% de oleico, 33,53% de linoleico e 2,39% de linolenico.