Biocidal Activity of a Nanoemulsion Containing Essential Oil from Protium heptaphyllum Resin against Aedes aegypti (Diptera: Culicidae)

This work aimed to prepare a nanoemulsion containing the essential oil of the Protium heptaphyllum resin and evaluate its biocidal activities against the different stages of development of the Aedes aegypti mosquito. Ovicide, pupicide, adulticide and repellency assays were performed. The main constituents were p-cymene (27.70%) and α-pinene (22.31%). The developed nanoemulsion showed kinetic stability and monomodal distribution at a hydrophilic–lipophilic balance of 14 with a droplet size of 115.56 ± 1.68 nn and a zeta potential of −29.63 ± 3.46 mV. The nanoemulsion showed insecticidal action with LC₅₀ 0.404 µg·mL⁻¹ for the ovicidal effect. In the pupicidal test, at the concentration of 160 µg·mL⁻¹, 100% mortality was reached after 24 h. For adulticidal activity, a diagnostic concentration of 200 µg·mL⁻¹ (120 min) was determined. In the repellency test, a concentration of 200 µg·mL⁻¹ during the 180 min of the test showed a protection index of 77.67%. In conclusion, the nanobiotechnological product derived from the essential oil of P. heptaphyllum resin can be considered as a promising colloid that can be used to control infectious disease vectors through a wide range of possible modes of applications, probably as this bioactive delivery system may allow the optimal effect of the P. heptaphyllum terpenes in aqueous media and may also induce satisfactory delivery to air interfaces.     

Bioassay-Guided Fractionation of Siparuna glycycarpa n-Butanol Extract with Inhibitory Activity against Influenza A(H1N1)pdm09 Virus by Centrifugal Partition Chromatography (CPC)

Siparuna glycycarpa occurs in the Amazon region, and some species of this genus are used in Brazilian folk medicine. A recent study showed the inhibitory effect of this species against influenza A(H1N1)pdm09 virus, and in order to acquire active fractions, a polar solvent system n-butanol-methanol-water (9:1:10, v/v) was selected and used for bioassay-guided fractionation of n-butanol extract by centrifugal partition chromatography (CPC). The upper phase was used as stationary phase and the lower phase as mobile (descending mode). Among the collected fractions, the ones coded SGA, SGC, SGD, and SGO showed the highest antiviral inhibition levels (above 74%) at 100 µg·mL⁻¹ after 24 h of infection. The bioactive fractions chemical profiles were investigated by LC-HRMS/MS data in positive and negative ionization modes exploring the Global Natural Products Social Molecular Networking (GNPS) platform to build a molecular network. Benzylisoquinoline alkaloids were annotated in the fractions coded SGA, SGC, and SGD collected during elution step. Aporphine alkaloids, O-glycosylated flavonoids, and dihydrochalcones in SGO were acquired with the change of mobile phase from lower aqueous to upper organic. Benzylisoquinolinic and aporphine alkaloids as well as glycosylated flavonoids were annotated in the most bioactive fractions suggesting this group of compounds as responsible for antiviral activity.     

First Measurement of a Thermochemical Property of a Seaborgium Compound

With only a few atoms of seaborgium (Sg, element 106), in the form of volatile SgO₂Cl₂, it was possible to determine the sublimation enthalpy of this compound using gas chromatography. Furthermore, it was demonstrated that in Group 6 Sg is chemically more similar to W than to Mo.     

α‐Cyclodextrin and methylmercury chloride: a new strategy to recover organomercurials

Methylmercury (MeHg) is one of the most toxic forms of mercury in the environment. It can be accumulated in fish through the food chain; after, consumption the fish is then dangerous to fetuses and younger children, causing abnormal brain development and nervous system disorders. Cyclodextrins (CDs) are cyclic oligosaccharides consisting of six, seven or eight units of glucose. In accord with the dimensions and hydrophilic–lipophilic properties, one can obtain inclusion of hydrophobic guests in a CD cavity. In the present work we used this characteristic of CD to obtain an inclusion compound between MeHgCl and the α‐cyclodextrin, looking for a new method to reduce MeHgCl toxicity and pre‐concentration. The inclusion compound was characterized through IR, ¹H, ¹³C NMR and Raman spectroscopy. ­X‐ray diffraction and thermal analysis (TG, DTG and DSC) methods were also used. Finally, biological tests were carried out and the minimum inhibitory concentrations (MICs) for MeHgCl, α‐cyclodextrin, the MeHgCl–CD complex and a physical mixture were determined. This host–guest strategy using cyclodextrins offers an alternative and powerful method for mercury remediation. Copyright © 2000 John Wiley & Sons, Ltd.     

Multiscale Entropy Analysis of Short Signals: The Robustness of Fuzzy Entropy-Based Variants Compared to Full-Length Long Signals

Multiscale entropy (MSE) analysis is a fundamental approach to access the complexity of a time series by estimating its information creation over a range of temporal scales. However, MSE may not be accurate or valid for short time series. This is why previous studies applied different kinds of algorithm derivations to short-term time series. However, no study has systematically analyzed and compared their reliabilities. This study compares the MSE algorithm variations adapted to short time series on both human and rat heart rate variability (HRV) time series using long-term MSE as reference. The most used variations of MSE are studied: composite MSE (CMSE), refined composite MSE (RCMSE), modified MSE (MMSE), and their fuzzy versions. We also analyze the errors in MSE estimations for a range of incorporated fuzzy exponents. The results show that fuzzy MSE versions—as a function of time series length—present minimal errors compared to the non-fuzzy algorithms. The traditional multiscale entropy algorithm with fuzzy counting (MFE) has similar accuracy to alternative algorithms with better computing performance. For the best accuracy, the findings suggest different fuzzy exponents according to the time series length.     

Phytochemical Composition and Protective Effect of Vernonanthura polyanthes Leaf against In Vivo Doxorubicin-Mediated Toxicity

Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (syn.: Vernonia polyanthes Less) is popularly known as “assa-peixe” and its leaves are used in folk medicine mainly to treat respiratory diseases. In this study, we evaluated the cytogenotoxic and anticytogenotoxic potential of the V. polyanthes leaf aqueous extract (VpLAE) and its n-butanol fraction (n-BF) in the presence or absence of doxorubicin (DXR) (pre-, co-, and post-treatments) on a murine model for 24 h or 120 h. The micronucleus test (MN) and the comet assay were used to assess the cytogenotoxic and anticytogenotoxic potential of VpLAE and n-BF (250, 500, and 1000 mg/kg) administered via gavage to Swiss Webster mice. The chemical profiles of VpLAE and n-BF were assessed by liquid chromatography coupled to mass spectrometry, and their metabolites were putatively identified. Lastly, the possible biological activities related to the (anti) cytogenotoxicity of the compounds were predicted using the PASS online webserver. The in vivo results showed that different doses of VpLAE and n-BF did not present cytotoxic activity; however, the MN test revealed a slight mutagenic activity for the 24 h treatments. Moderate genotoxic effects were demonstrated for all treatments in the comet assay. Regarding anticytotoxicity and antimutagenicity, VpLAE and n-BF presented a high cytoprotective potential against DXR toxic effects. In the co-treatment, VpLAE reduced the DXR genotoxicity by ~27%, and n-BF did not demonstrate antigenotoxic potential. In contrast, an antigenotoxic effect was observed for both VpLAE and n-BF in the pre- and post-treatments, reducing DXR genotoxicity by ~41% and ~47%, respectively. Chemical analysis of VpLAE and n-BF showed the presence of eight phenolic compounds, including seven chlorogenic acids and a flavonoid. The PASS online tool predicted antimutagenic, anticancer, antineoplastic, chemoprotective, antioxidant, and radical scavenging activities for all constituents identified in VpLAE and n-BF. V. polyanthes leaves presented a protective effect against DXR cytogenotoxicity. In general, VpLAE and n-BF showed a greater antigenotoxic potential in the pre- and post-treatments. The metabolites putatively identified in VpLAE and n-BF exhibited antioxidant and chemoprotective potential according to computational prediction analysis. Altogether, our results highlight the potential application of V. polyanthes to protect against toxic manifestations induced by DXR.     

The Use of Seaweed and Sugarcane Bagasse for the Biological Treatment of Metal-contaminated Waters Under Sulfate-reducing Conditions

When wetlands reach maximum treatment capacity to remove heavy metals, removal can still take place through precipitation as sulfide because of the biological reduction of sulfate. To achieve this goal, anaerobic conditions must be attained, a sulfate source must exist, and an adequate substrate for sulfate-reducing bacteria (SRB) is also required. In the present work, two ligneous-cellulosic materials, a brown seaweed and sugarcane bagasse, have been selected as substrates for SRB growth. Experiments were simultaneously conducted in continuous operation in two columns (0.57 L each), one containing the ligneous-cellulosic material plus inoculum and another containing only the ligneous-cellulosic material. In this work, the removal of cadmium and zinc was studied because of their presence in effluents from mining/metallurgy operations. Results obtained indicated that the inoculated reactor was able to treat the effluent more efficiently than the noninoculated reactor considering the time course of the tests.