Pectis brevipedunculata is native species and widely available in dry and semi-arid ecosystems showing high biotechnological potential. The objective of this study was to evaluate the circadian and seasonal chemical variation of the essential oil (EO) of P. brevipedunculata, as well as its acaricide effect on Rhipicephalus microplus larvae. Aerial parts were collected and submitted to the hydrodistillation process, and the chemical composition was determined by gas chromatography mass spectrometry (GC-MS). For the assays with R. microplus, the larval immersion test was performed. The main constituents were citral (75% of the EO), followed by α-pinene and limonene. In the seasonality analysis, the highest yields were in the months of April (2.08%) and August (2.05%), while in the study of circadian rhythm, the percentage was 2.0% at 6 p.m. in the rainy season, and 1.2%, dry season at 6 p.m. Concerning acaricidal activity (50% lethal concentration (LC50)), the April (1.17 mg mL-1), March (1.28 mg mL-1), June (1.37 mg mL-1), and October (1.27 mg mL-1) oils obtained were the most active and assays performed with circadian rhythm revealed in the rain season (April) at 6 p.m. and dry season (September) at 12 a.m. LC50 values of 1.75 and 1.75 mg mL-1, respectively. Additionally, this EO is selective to non-target organisms, i.e., ladybeetles and lacewing.

Brazil has the greatest plant diversity on the planet, distributed in different types of biomes. These plants are important sources of biologically active natural products, which are derived from various drugs marketed worldwide. This paper presents an electrochemical study of three unusual dimeric flavonoids, pharmacologically active, isolated and identified for the first time by our research group, in a Brazilian plant (Fridericia platyphylla). The results showed that oxidation processes are favored at higher pH, and mass transport was controlled by diffusion. Brachydins derivatives, Bra-A was oxidized at the lowest potential value (0.48 V vs. Ag/AgCl, KCl(sat)) and Bra-B and Bra-C, presented the highest oxidation potentials (ca. 0.71 and ca. 0.57 V vs. Ag/AgCl, KCl(sat), respectively). This study shows that electrochemistry is one more tool that would help us focus on future bio-pharmacological investigations of these unusual compounds.

AbstractArrabidaea brachypoda Bureau, Bignoniaceae, known as "cipó-una", is widely used in traditional medicine in Southeastern and Northeastern Brazil for kidney stones and painful joints. This study was aimed at evaluating the anti-inflammatory proprieties of the oleanane-type triterpenoid 3β-estearioxy-olean-12-ene isolated from the roots of A. brachypoda. Carrageenan-induced paw oedema, formalin test and hot plate test were used to investigate the antiinflammatory activity of 3β-estearioxy-olean-12-ene in animals. We observed that 3β-estearioxy-olean-12-ene at doses of 5, 10 and 15 mg/kg p.o. demonstrated anti-inflammatory effects, by reduced (p < 0.05) paw oedema induced by carrageenan and by decreased (p < 0.05) licking time caused by a subplantar injection of formalin. In conclusion, 3β-estearioxy-olean-12-ene, a triterpene isolated from the roots of A. brachypoda, demonstrate anti-inflammatory effect in different tests. Thus, it may be useful in the treatment of inflammatory disorders, which supports previous claims of its traditional use.