The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance (‘1’) identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance (‘1’) tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower IC50 values. In cytotoxic tests, the 2 extracts and substance ‘1’ showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.

Cerrado biome represents an area with great biodiversity. Some of its plants have significant ethnopharmacological uses, with specific purposes. Croton urucurana Baill., for instance, was previously acknowledged for its anti-hemorrhagic, anti-inflammatory, antiseptic, healing, and potentially antifungal and entomopathogenic actions. Nevertheless, the compounds supporting these empirical applications are still unknown. Accordingly, this work was designed to achieve a complete characterization of the phenolic profile of different botanical tissues obtained from C. urucurana, and also to verify how different operational conditions (different drying temperatures and extraction conditions) affect that profile. All samples were further characterized by HPLC–DAD–ESI/MSn, and results were compared by advanced chemometric tools. In general, the drying temperatures that maximize the extraction yield of specific individual phenolic compounds were established. Likewise, it was possible to verify that samples extracted with the hydroethanolic solution allowed higher phenolic yields, either in individual compounds (except (epi)catechin-di-O-gallate) or total phenolics. The identification of the best operational conditions and phenolic profiles associated with each C. urucurana botanical part contributes to enabling their use in food or pharmaceutical-related applications.

a b s t r a c tCarbon-supported catalysts containing platinum and molybdenum oxide are prepared by thermal decomposition of polymeric precursors. The Pt y Mo z O x /C materials are characterized by energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray diffraction. The catalysts present a well-controlled stoichiometry and nanometric particles. Molybdenum is present mainly as the MoO 3 orthorhombic structure, and no Pt alloys are detected. The voltammetric behavior of the electrodes is investigated; a correlation with literature results for PtMo/C catalysts prepared by other methods is established. The formation of soluble species and the aging effect are discussed.

O estudo da atividade alelopática vem sendo utilizado no combate e controle de doenças, insetos e plantas daninhas. Este trabalho teve por objetivo avaliar o efeito alelopático de extratos das folhas de caju-de-árvore-do-cerrado (Anacardium othonianum Rizz.) na germinação e no crescimento inicial de plântulas de alface (Lactuca sativa L.) e rabanete (Raphanus sativus L.). Inicialmente, foram obtidos extratos aquosos das folhas da planta in natura por dois métodos de extração aquosa: infusão e decocção. Os bioensaios de germinação e crescimento de alface e rabanete foram realizados em triplicata, com tratamentos compostos por seis diferentes diluições dos extratos, sendo feita a análise da porcentagem de germinação, comprimento de radículas e da parte aérea das plântulas após 7 dias de incubação, sob condições de temperatura e luz artificiais. Verificou-se a existência do potencial alelopático em ambos os extratos das folhas de caju-de-árvore-do-cerrado, pela sensibilidade observada nas sementes de alface e rabanete. Além disso, constatou-se que os efeitos dos aleloquímicos são dependentes da dosagem utilizada, já que foram observadas variações nos efeitos alelopáticos (inibitório e/ou estimulante) apenas alterando a concentração aplicada dos extratos.

The study was designed to evaluate the ethanolic extract acaricide action from Pouteria gardneriana Radlk specie adsorbed in chitosan nanoparticles for controlled release against Riphicephalus (Boophilus) microplus. Leaves of P. gardneriana Radlk were collected, air-dried, ground and extracted with ethanol. Chitosan nanospheres were obtained by the phase inversion method. Conductometric titration, UV-Vis and FTIR analysis were conducted with the materials to evaluate the chitosan anchoring ability. In vitro test was performed using engorged females for each treatment, which consisted of the control, raw extract and three treatments diluted, with increasing concentrations of 0.2, 0.4 and 1%. The most effectiveness extract was for 0.4% concentration by observing reduction in the eggs mass compared to control group. The nanomaterial proved to be able to anchor and release the insecticide gradually in pH between 5 and 6 regions, which makes it feasible for use in cattle, prolonging the exposure time between the tick and acaricide.