Essential oils extracted from Schinus molle L. and Schinus terebinthifolius Raddi, Anacardiaceae, leaves and fruit hydrodistillation, as well as, their chemical composition and extraction kinetic were evaluated. For this proposal, 6h extraction and aliquots collected at sequencing different times (0.5, 1, 2, 4 and 6h) were carried out allowing calculating accumulated content (% w/w) and verifying essential oil chemical profile. β-caryophyllene (35.2%), α-pinene (28.1%) and germacrene D (15.5%) represent S. terebinthifolius dried leaves essential oil major components, as well as, α-pinene (44.9%), germacrene D (17.6%) and β-pinene (15.1%) in the fruit. Cubenol (27.1%), caryophyllene oxide (15.3%) and spathulenol (12.4%) represent S. molle dried leaves essential oil major components, and β-pinene (36.3%) α-pinene (20.3%), germacrene D (12.1%) and spathulenol in the fruit. Essential oil extraction kinetics showed a hyperbolic distribution; monoterpene content presented exponential decay in time function and sesquiterpene showed exponential growth. Faster monoterpene extraction than the sesquiterpene extraction was observed, however, both presented increasing exponential distribution

SUMMARY: Extracts and essential oils from plants are important natural sources of pesticides. These compounds are considered an alternative to control ectoparasites of veterinary importance. Schinus molle, an endemic species of Brazil, produces a high level of essential oil and several other compounds. The aim of this work was to determinate the chemical composition of extracts and essential oils of S. molle and further to evaluate the activity against eggs and adults of Ctenocephalides felis felis, a predominant flea that infests dogs and cats in Brazil. In an in vitro assay, the non-polar (n-hexane) extract showed 100% efficacy (800 µg cm⁻²; LD₅₀ = 524·80 µg cm⁻²) at 24 and 48 h. Its major compound was lupenone (50·25%). Essential oils from fruits and leaves were evaluated, and had 100% efficacy against adult fleas at 800 µg cm⁻² (LD₅₀ = 353·95 µg cm⁻²) and at 50 µg cm⁻² (LD₅₀ = 12·02 µg cm⁻²), respectively. On the other hand, the essential oil from fruits and leaves was not active against flea eggs. This is the first study that reports the insecticidal effects of essential oils and extracts obtained from Schinus molle against Ctenocephalides felis felis.

The effects of 25, 50, 75 and 100% of light intensity (137, 254, 406 and 543 μmol photons m⁻² second⁻¹, respectively) on aspects related to volatile synthesis in menthol mint were investigated. Fresh weight production, glandular trichome density and essential oil content showed a significant linear positive correlation with light intensity. Plants under low light intensity (25%) produced an essential oil with high levels of neomenthol, menthol and menthyl acetate. With 50 and 75% of light intensity plants showed an increase in expression of limonene synthase, limonene hydroxylase, (-)-isopiperitenol dehydrogenase, (+)-pulegone reductase and menthol dehydrogenase genes and an anticipation in oil maturity. With 25% of light intensity plants produced an essential oil with the best commercial profile. However, plants under 100% of light intensity produced more essential oil but with lower levels of menthol and higher levels of pulegone, that can be toxic for humans.

Essential oils (EOs) are considered a new class of ecological products aimed at the control of insects for industrial and domestic use; however, there still is a lack of studies involving the control of fleas. Ctenocephalides felis felis, the most observed parasite in dogs and cats, is associated with several diseases. The aim of this study was to evaluate the in vitro activity, the establishment of LC₅₀ and toxicity of EOs from Alpinia zerumbet (Pers.) B. L. Burtt & R. M. Sm, Cinnamomum spp., Laurus nobilis L., Mentha spicata L., Ocimum gratissimum L. and Cymbopogon nardus (L.) Rendle against immature stages and adults of C. felis felis. Bioassay results suggest that the method of evaluation was able to perform a pre-screening of the activity of several EOs, including the discriminatory evaluation of flea stages by their LC₅₀. Ocimum gratissimum EO was the most effective in the in vitro assays against all flea stages, presenting adulticide (LC₅₀ = 5.85 μg cm⁻²), ovicidal (LC₅₀ = 1.79 μg cm⁻²) and larvicidal (LC₅₀ = 1.21 μg cm⁻²) mortality at low doses. It also presented an excellent profile in a toxicological eukaryotic model. These findings may support studies involving the development of non-toxic products for the control of fleas in dogs and cats.