Biosurfactants produced by Pseudomonas syringae pv tabaci: A versatile mixture with interesting emulsifying properties

In recent years, worldwide awareness about environmental concerns has led to an extensive searching for products of natural origin. Biosurfactants (BS), are an attractive alternative to the chemical counterparts. In these sense, this works evaluate for the first time the emulsifying and surface activity of biosurfactants produced by P. syringae pv. tabaci. Chemical characterization revealed that the produced BS extract mostly consisted in a mixture of syringopeptins and arthrofactins. Besides, this sample was able to reduce water surface tension up to 36.89 mN/m. This activity was improved by modifying conditions of pH, temperature and salinity. For instance, the surface tension was reduced up to 29 mN/m when using NaCl 5 % w/w. The BS also exhibited a high emulsifying activity, this being comparable or even superior to that of commercial bioemulsifiers such xanthan, tara and guar gums. A notorious emulsification index, close to 90 %, was exhibited by BS in coconut oil/water mixtures. Moreover, emulsifying activity resulted to be little affected by different operational conditions, thus retaining about 80 % of its emulsificant index in presence of 20 % w/w of NaCl at 80 °C. These findings are indicative of the BS promising properties and its potential as additive in a variety of industrial applications.Fil: Haidar, Carla Nahir. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Procesos Biotecnológicos y Químicos Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Procesos Biotecnológicos y Químicos Rosario; ArgentinaFil: Pereira, Matheus M.. Universidade Tiradentes; BrasilFil: Lima, Álvaro S.. Universidade Tiradentes; BrasilFil: Nerli, Bibiana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Procesos Biotecnológicos y Químicos Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Procesos Biotecnológicos y Químicos Rosario; ArgentinaFil: Pellegrini Malpiedi, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Procesos Biotecnológicos y Químicos Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Procesos Biotecnológicos y Químicos Rosario; Argentin

Enzyme kinetics, structural analysis and molecular modeling studies on a series of Schistosoma mansoni PNP inhibitors

The enzyme purine nucleoside phosphorylase from Schistosoma mansoni (SmPNP) is an attractive molecular target for the development of novel drugs against schistosomiasis, a neglected tropical disease that affects about 200 million people worldwide. In the present work, enzyme kinetic studies were carried out in order to determine the potency and mechanism of inhibition of a series of SmPNP inhibitors. In addition to the biochemical investigations, crystallographic and molecular modeling studies revealed important molecular features for binding affinity towards the target enzyme, leading to the development of structure-activity relationships (SAR).A enzima purina nucleosídeo fosforilase do parasita Schistosoma mansoni (SmPNP) é um alvo molecular atrativo para o desenvolvimento de candidatos a novos fármacos para o tratamento da esquistossomose, doença tropical negligenciada que afeta mais de 200 milhões de pessoas em todo mundo. No presente trabalho, estudos de cinética enzimática foram conduzidos para a determinação da potência e do mecanismo de inibição de uma série de inibidores da enzima SmPNP. Além das investigações bioquímicas, estudos cristalográficos e de modelagem molecular revelaram importantes bases moleculares para a afinidade de ligação frente à enzima alvo, levando ao desenvolvimento de relações entre a estrutura e atividade (SAR).(FAPESP) São Paulo Research FoundationFundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)(CNPq) National Council for Scientific and Technological Developmen

Influence of Alloying Elements and Solution Heat Treatment on Microstructure and Microhardness of the Ni-Nb-M System (M = Al, Ti, Cr, Fe)

Ni-based superalloys are widely used in critical components of aircraft engines and turbines and also in the petrochemical industry, for applications in highly corrosive environments. These alloys have as main characteristics their superior mechanical, corrosion and oxidation resistance at high temperatures, as well as creep resistance. The chemical composition associated with carrying out heat treatments directly influences the phases formed (such as the ordered cubic phase γ’-Ni3(Al,Ti) in the fcc γ-Ni matrix), and depending on the alloying elements and fraction, there is the possibility of an increase in mechanical strength. There is a certain gap in the literature regarding the study of ternary superalloys based on Ni-Nb, and the influence of the third alloying element on the microstructure and microhardness. In this context, the objective of the study is to characterize pseudo-eutectic alloys of the Ni-15Nb-xM and Ni-20Nb-xM systems (xM = 2Al, 4Ti, 15Fe and 15Cr, wt.%) and investigate the influence of alloy elements and solution heat treating on their microstructure and properties through X-Ray Diffraction, Optical Microscopy, Scanning Electron Microscopy and Vickers Microhardness. Microhardness and microstructures were significantly influenced by the addition of alloying elements. The addition of Cr had a significant effect on the hardness of the cast samples. All alloys showed microhardness and microstructural changes after solution heat treatment

OVOS CAIPIRAS: manejo baseado no bem estar animal agrega valor à produção de pequeno porte produtor

Nas últimas décadas temos observado uma mudança no paradigma da produção, a busca por alimentos produzidos em grande escala sustentada por pacotes tecnológicos que agridem o ambiente e aos consumidores, vem dando lugar à produção de alimentos socialmente e ambientalmente referenciados

β-cyclodextrin/isopentyl caffeate inclusion complex: synthesis, characterization and antileishmanial activity

Isopentyl caffeate (ICaf) is a bioactive ester widely distributed in nature. Our patented work has shown promising results of this molecule against Leishmania. However, ICaf shows poor solubility, which limits its usage in clinical settings. In this work, we have proposed the development of an inclusion complex of ICaf in -cyclodextrin (-CD), with the aim to improve the drug solubility, and thus, its bioavailability. The inclusion complex (ICaf:-CD) was developed applying three distinct methods, i.e., physical mixture (PM), kneading (KN) or co-evaporation (CO) in different molar proportions (0.25:1, 1:1 and 2:1). Characterization of the complexes was carried out by thermal analysis, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and molecular docking. The ICaf:-CD complex in a molar ratio of 1:1 obtained by CO showed the best complexation and, therefore, was selected for further analysis. Solubility assay showed a marked improvement in the ICaf:-CD (CO, 1:1) solubility profile when compared to the pure ICaf compound. Cell proliferation assay using ICaf:-CD complex showed an IC50 of 3.8 and 2.7 µg/mL against L. amazonesis and L. chagasi promastigotes, respectively. These results demonstrate the great potential of the inclusion complex to improve the treatment options for visceral and cutaneous leishmaniases.This research was funded by Banco do Nordeste (grant FUNDECI/2016.0015), Coordenação Aperfeiçoamento de Pessoal de Nivel Superior (CAPES) and Fundação de Ámparo à Pesquisa do Estado de Sergipe (FAPITEC) (PROCESSO: 88887.159533/2017-00 extração, encapsulação e caracterização de bioativos para o interesse biotecnologico). Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 301964/2019-0 Chamada 06/2019, and Chamada CNPq nº 01/2019) and from the Portuguese Science and Technology Foundation (FCT) project UIDB/04469/2020 (strategic fund).info:eu-repo/semantics/publishedVersio

Anti-tumor efficiency of Perillylalcohol/β-Cyclodextrin inclusion complexes in a sarcoma S180-induced mice model

The low solubility and high volatility of perillyl alcohol (POH) compromise its bioavailability and potential use as chemotherapeutic drug. In this work, we have evaluated the anticancer activity of POH complexed with -cyclodextrin (-CD) using three complexation approaches. Molecular docking suggests the hydrogen-bond between POH and -cyclodextrin in molar proportion was 1:1. Thermal analysis and Fourier-transform infrared spectroscopy (FTIR) confirmed that the POH was enclosed in the -CD cavity. Also, there was a significant reduction of particle size thereof, indicating a modification of the -cyclodextrin crystals. The complexes were tested against human L929 fibroblasts after 24 h of incubation showing no signs of cytotoxicity. Concerning the histopathological results, the treatment with POH/-CD at a dose of 50 mg/kg promoted approximately 60% inhibition of tumor growth in a sarcoma S180-induced mice model and the reduction of nuclear immunoexpression of the Ki67 antigen compared to the control group. Obtained data suggest a significant reduction of cycling cells and tumor proliferation. Our results confirm that complexation of POH/-CD not only solves the problem related to the volatility of the monoterpene but also increases its efficiency as an antitumor agent.This work was supported by the Banco do Nordeste (grant FUNDECI/2016.0015), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Apoio à Pesquisa e à Inovação Tecnológica do Estado de Sergipe (Fapitec) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Eliana B. Souto would like to acknowledge the Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) for the project UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

Rutin-functionalized multi-walled carbon nanotubes: molecular docking, physicochemistry and cytotoxicity in fibroblasts

Multi-Walled Carbon Nanotubes (MWCNT) have been functionalized with rutin through three steps (i. reaction step; ii. purification step; iii. drying step) and their physicochemical properties investigated with respect to morphological structure, thermal analysis, Fourier Transform Infrared Spectroscopy (FTIR), and cytotoxicity. The molecular docking suggested the rutin-functionalized MWCNT occurred by hydrogen bonds, which was confirmed by FTIR assays, corroborating the results obtained by thermal analyses. A tubular shape, arranged in a three-dimensional structure, could be observed. Mild cytotoxicity observed in 3T3 fibroblasts suggested a doseeffect relationship after exposure. These findings suggest the formation of aggregates of filamentous structures on the cells favoring the cell penetration.The authors acknowledge Classius Ferreira da Silva, from the Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, for the scanning electron microscopy analyses.info:eu-repo/semantics/publishedVersio

Efeitos não-alvo de inseticidas utilizados para controle de Bemisia tabaci (Gennadius, 1889) biótipo B (Hemiptera: Aleyrodidae) sobre a mortalidade e biologia de Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) em soja [Glycine max (l.) Merrill]

Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is a polyphagous pest that has gained importance in soybean cultivation in recent years, due to the damage it causes to leaves and pods. The objective of this work was to evaluate the non-target effect of insecticides recommended and used to control Bemisia tabaci (Genn.) biotype B on S. frugiperda. The experimental design was entirely randomized with five treatments and fifty replications. The treatments were: 1. negative control (distilled water), 2. positive control (lufenuron), 3. buprofezin, 4. pyriproxyfen, and 5. diafenthiuron. In each replicate, one caterpillar was placed in a plastic cup, where sprayed soybean leaves with the maximum dosage of insecticides recommended for B. tabaci were placed.The treatments were evaluated daily during all stages: larval, pupal, and adult emergence and fecundity. The results obtained for larval mortality showed that diafenthiuron aimed 100% control, followed by pyriproxyfen with 28% and buprofezin with 12%. The duration of the larval period of the insects exposed to pyriproxyfen and buprofezin were longer compared to the control. While the biological parameters of pupae were found that pyriproxyfen caused lower pupal formation rate and higher pupal mortality, followed by buprofezin. In adult emergence, pyriproxyfen showed the lowest rate with 13.8% and the highest percentage of deformed adults with 60%. Thus, it was possible to conclude that the insecticides under study cause S. frugiperda mortality or effects on its biological patterns

An investigation into the stability of an oregano essential oil emulsion for the preparation of microparticles using spray drying.

The objective of this study was to evaluate the viscosity, zeta potential and soluble and total solids of the emulsion and microparticles of oregano essential oil (Origanum vulgare) using gum arabic as a coating agent and to analyze the morphology of the microparticles produced by the spray drying method. The rheological analysis showed a viscosity for emulsion of 36.23 ± 0.59 mPas and for microparticles of 20.13 ± 0.15 mPa.s. The zeta potential of the emulsion was - 6.67 ± 0.32 mV and of the oregano oil microparticles -16.47 ± 0.70 mV. Soluble solids showed Brix° of 8.44 ± 0.13 and 0.98 ± 0.36 and total solids 8.95 ± 0.42 and 1.03 ± 0.02 % for emulsion and microparticles, respectively. The morphology of the microparticles presented irregular spherical shapes and agglomeration