Synthesis and virucide activity on zika virus of 1,2,3-triazole-containing vanillin derivatives.

The Zika virus (ZIKV) is an arbovirus and belongs to the Flaviviridae family and Flavivirus genus, with dissemination in the Americas. In Brazil, the predominant strain is the Asian, promoting outbreaks that started in 2015 and are directly related to microcephaly in newborns and Guillain-Barré syndrome in adults. Recently, researchers identified a new African strain circulating in Brazil at the mid-end of 2018 and the beginning of 2019, with the potential to originate a new epidemic. To date, there is no approved vaccine or drug for the treatment of Zika syndrome, and the development of therapeutic alternatives to treat it is of relevance. A critical approach is to use natural products when searching for new chemical agents to treat Zika syndrome. The present investigation describes the preparation of a series of 1,2,3-triazoles derived from the natural product vanillin and the evaluation of their virucide activity. A series of fourteen derivatives were prepared via alkylation of vanillin followed by CuAAC (the copper(I)-catalyzed azide-alkyne cycloaddition) reaction. The compounds were fully characterized by infrared (I.R.), nuclear magnetic resonance (NMR), and high-resolution mass spectrometry (HRMS) techniques. The cytotoxicity of Vero cells and the effect on the Zika Virus of the vanillin derivatives were evaluated. It was found that the most effective compound corresponded to 4-((1-(4-isopropylbenzyl)-1H-1,2,3-triazol-4-yl)methoxy)-3-methoxybenzaldehyde (8) (EC50 = 27.14 µM, IC50 = 334.9 µM). Subsequent assessments, namely pre and post-treatment assays, internalization and adsorption inhibition assays, kinetic, electronic microscopy analyses, and zeta potential determination, revealed that compound 8 blocks the Zika virus infection in vitro by acting on the viral particle. A molecular docking study was performed, and the results are also discussed.

A highly specific Serratia-infecting T7-like phage inhibits biofilm formation in two different genera of the Enterobacteriaceae family.

Due to the emergence of multidrug-resistant bacteria, bacteriophages have become a viable alternative in controlling bacterial growth or biofilm formation. Biofilm is formed by extracellular polymeric substances (EPS) and is one of the factors responsible for increasing bacterial resistance. Bacteriophages have been studied as a bacterial control agent by use of phage enzymes or due to their bactericidal activities. A specific phage against Serratia marcescens was isolated in this work and was evaluated its biological and genomic aspects. The object of this study was UFV01, a bacteriophage belonging to the Podoviridae family, genus Teseptimavirus (group of lytic viruses), specific to the species S. marcescens, which may be related to several amino acid substitutions in the virus tail fibers. Despite this high specificity, the phage reduced the biofilm formation of several Escherichia coli strains without infecting them. UFV01 presents a relationship with phages of the genus Teseptimavirus, although it does not infect any of the E. coli strains evaluated, as these others do. All the characteristics make the phage an interesting alternative in biofilm control in hospital environments since small breaks in the biofilm matrix can lead to a complete collapse.

Xanthenedione (and intermediates involved in their synthesis) inhibit Zika virus migration to the central nervous system in murine neonatal models.

Zika Virus (ZIKV), an arbovirus that belongs to the Flaviviridae family, has become a global concern since its outbreak in the Americas in 2015. With symptoms similar to other Flavivirus as Dengue and Yellow Fever viruses, infections by ZIKV have also been related to several neurological complications such as microcephaly in newborns and Guillain-Barre syndrome. Considering the high prevalence of ZIKV infection in certain areas, the risks that the virus poses to fetal brain development, and the fact that there is no vaccine or specific prophylaxis available, an effective treatment capable of preventing the infection is of potential interest. Therefore, in the present investigation, the antiviral activity on ZIKV of a group of xanthenodiones and intermediate ketones involved in their synthesis was evaluated for the first time. It was found that the compound 2-(2,6-dichlorobenzylidene)cyclohexane-1,3-dione 27 was able to completely inhibit the viral infection of Vero cells as well as to significantly reduce viral load in the brains of newborn Swiss mice. These effects are related to a direct interaction of the compound with the viral particle, blocking the viral adsorption.

Heterotrophic nitrifying/aerobic denitrifying bacteria: Ammonium removal under different physical-chemical conditions and molecular characterization.

Biological ammonium removal via heterotrophic nitrification/aerobic denitrification (HN/AD) was characterized for two isolates from a wastewater treatment station (WWTS). They were identified as Pseudomonas balearica UFV3 and Gordonia amicalis UFV4. Their ability to remove ammonium via NH/DA was validated by chromatography, and the influence of different physical-chemical factors on removal was evaluated. The presence of genes involved in conventional nitrification and denitrification processes was investigated via PCR and comparative genomics. Both isolates removed 100% of the ammonium in a medium containing citrate as its carbon source with a C/N ratio of 8, 3% salt, pH 7 and 30 °C. Nitrogen balance showed that approximately 55% of the ammonium removed was lost as N2(g), and 45% was assimilated. Molecular characterization revealed the absence of genes involved in autotrophic nitrification in the genome of the two isolates and the presence of genes involved in anaerobic denitrification only in P. balearica UFV3, suggesting the involvement of other genes in the HN/AD process. This was the first report of G. amicalis and P. balearica with the capability for HN/AD.

The use of the carbon/nitrogen ratio and specific organic loading rate as tools for improving biohydrogen production in fixed-bed reactors.

This study assessed the effect of the carbon/nitrogen (C/N) ratio on the hydrogen production from sucrose-based synthetic wastewater in upflow fixed-bed anaerobic reactors. C/N ratios of 40, 90, 140, and 190 (g C/g N) were studied using sucrose and urea as the carbon and nitrogen sources, respectively. An optimum hydrogen yield of 3.5 mol H2 mol-1 sucrose was obtained for a C/N ratio of 137 by means of mathematical adjustment. For all C/N ratios, the sucrose removal efficiency reached values greater than 80% and was stable after the transient stage. However, biogas production was not stable at all C/N ratios as a consequence of the continuous decreasing of the specific organic loading rate (SOLR) when the biomass accumulated in the fixed-bed, causing the proliferation of H2-consuming microorganisms. It was found that the application of a constant SOLR of 6.0 g sucrose g-1 VSS d-1 stabilized the system.