Effect of mating delay on the ovary of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae) queens

The effect of mating delay on the ovary structure of virgin queens of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae) was investigated. Virgin queens 15, 20, 25 and 30 days old were dissected to analyze their degree of ovary degeneration. To verify whether the degeneration would cause permanent sterility, virgin queens of the same ages (15, 20, 25 and 30 days) were mated and accompanied for at least 14 days to verify whether there was physogastry and then dissected. The ovaries were analyzed by histology, histochemical tests and TUNEL to verify programmed cell death. The results showed that mating delay interrupted oogenesis preventing vitellogenesis. Mating delay results in ovary degeneration which increased with queen age. However, even when there was ovariole degeneration, 25-day-old virgin queens after mating presented normal ovariole activation.     

Heterocyclic compounds as antiviral drugs: Synthesis,structure–activity relationship and traditional applications

A virus outbreak challenges the economic, medical, and public health infrastructure worldwide. More than one virus capable of triggering diseases have been identified per year since 1972, which requires the development of new ways of treatment and prevention, however, such processes are not rapid and easy. With the pandemic scenario experienced since early 2020, several drugs with well-known purposes have gained prominence, due to speculation of their use in the treatment against the new coronavirus. Among the main drugs studied, the vast majority contain a heterocyclic structure. In this review, we presented the traditional and efficient synthesis of 15 drugs that have been studied for the COVID-19 treatment, containing in their structure heterocycles like indole, quinoline, pyrimidone, tetrahydrofuran, pyrrolidine, triazole, pyridazine, pyrazole, pyrrolopyrimidine, azetidine, pyrrolotriazine, pyrazine, tetrahydropyran, benzofuran, spiroketal, and thiazole. Furthermore, we have shown the original applications, as well as their structure–activity relationship and what is their situation as a drug candidate against COVID-19. Thus, the objective was to consolidate the main synthetic and pharmacological aspects involving clinically developed heterocycles that at some point were presented as promising against SARS-CoV-2.     

Methane conversion to higher value-added product and energy co-generation using anodes OF PdCu/C in a solid electrolyte reactor: alkaline fuel cell type monitored by differential mass spectroscopy

Research on Chemical Intermediates - PdxCuy/C catalysts combinations were employed to CH4 partial oxidation in mild condition using a solid electrolyte reactor—alkaline fuel cell type. The...     

Quantification of Intact and Truncated Stromal Cell-Derived Factor-1α in Circulation by Immunoaffinity Enrichment and Tandem Mass Spectrometry

Stromal cell-derived factor 1α (SDF-1α) or CXCL12 is a small pro-inflammatory chemoattractant cytokine and a substrate of dipeptidyl peptidase IV (DPP-IV). Proteolytic cleavage by DPP-IV inactivates SDF-1α and attenuates its interaction with CXCR4, its cell surface receptor. To enable investigation of suppression of such inactivation with pharmacologic inhibition of DPP-IV, we developed quantitative mass spectrometric methods that differentiate intact SDF-1α from its inactive form. Using top-down strategy in quantification, we demonstrated the unique advantage of keeping SDF-1α’s two disulfide bridges intact in the analysis. To achieve the optimal sensitivity required for quantification of intact and truncated SDF-1α at endogenous levels in blood, we coupled nano-flow tandem mass spectrometry with antibody-based affinity enrichment. The assay has a quantitative range of 20 pmol/L to 20 nmol/L in human plasma as well as in rhesus monkey plasma. With only slight modification, the same assay can be used to quantify SDF-1α in mice. Using two in vivo animal studies as examples, we demonstrated that it was critical to differentiate intact SDF-1α from its truncated form in the analysis of biomarkers for pharmacologic inhibition of DPP-IV activity. These novel methods enable translational research on suppression of SDF-1 inactivation with DPP-IV inhibition and can be applied to relevant clinical samples in the future to yield new insights on change of SDF-1α levels in disease settings and in response to therapeutic interventions.

Characterization of Pentaclethra macroloba oil

The Pracaxi oil—(Pentaclethra macroloba) contains high concentrations of fatty acids with emollient action that contribute to skin hydration. The use of this oil is supported by the utilization of natural resources thus enabling regional development and social contribution. The objective of this study was to characterize the P. macroloba oil by thermogravimetry (TG, DTG, and DTA), gas chromatography, Fourier transform infrared spectroscopy (FT-IR), and oxidation stability—Rancimat, aiming at the quality control of plant raw material. Three samples of crude oil sold by Amazon Oil Industry (Ananindeua, Pará, Brazil) were studied. The analysis of these oil samples showed different fatty acids, especially the behenic, oleic, linoleic, and lignoceric acids totalizing approximately 96 % of the grease composition and in smaller percentage arachidic, lauric, myristic, palmitic, and linolenic acids were found. The major acids have wide medicinal use. According to the TG/DTG curve, thermal stability was observed up to 220 °C, indicating a greater mass loss related to the dehydration and elimination of volatile substances. The thermal decomposition process occurred in the range of 430–450° C according to the DTG curve. The absorption spectrum in the infrared region (FT-IR) showed well-defined bands confirming the presence of functional groups present in the oil. Tests in a Rancimat have shown an induction period between 8 and 10 h demonstrating that the samples are in agreement with the standards required by ANP No. 14/2012 which requires at least 6 h of testing.     

Ordered Mesoporous ZSM‐5 Employing an Imidazolium‐Based Ionic Liquid

Hierarchically porous ZSM‐5 was achieved by using a simple bottom‐up strategy combining zeolite seeds with imidazolium‐based ionic liquids. The bimodal ZSM‐5 with hexagonal arranged mesopores (3 nm) shows important activity in the acid catalysis of bulky compounds relative to conventional ZSM‐5.     

The Formation of Imidazolium Salt Intimate (Contact) Ion Pairs in Solution

1‐n‐Butyl‐2,3‐dimethylimidazolium (BMMI) ionic liquids (ILs) associated with different anions undergo H/D exchange preferentially at 2‐Me group of the imidazolium in deuterated solvents. This process is mainly related to the existence of ion pairs rather than the anion basicity. The H/D exchange occurs in solvents (CDCl₃ and MeCN for instance) in which intimate contact ion pairs are present and the anion possesses a labile H in its structure, such as hydrogen carbonate and prolinate. In D₂O, separated ion pairs are formed and the H/D exchange does not occur. A plausible catalytic cycle is that the IL behaves as a neutral base in the course of all H/D exchange processes. NMR experiments, density functional calculations, and molecular dynamics simulations corroborate these hypotheses.     

Biomethane Production in an AnSBBR Treating Wastewater from Biohydrogen Process

An anaerobic sequencing batch reactor containing immobilized biomass (AnSBBR) was used to produce biomethane by treating the effluent from another AnSBBR used to produce biohydrogen from glucose- (AR-EPHG) and sucrose-based (AR-EPHS) wastewater. In addition, biomethane was also produced from sucrose-based synthetic wastewater (AR-S) in a single AnSBBR to compare the performance of biomethane production in two steps (acidogenic and methanogenic) in relation to a one-step operation. The system was operated at 30 °C and at a fixed stirring rate of 300 rpm. For AR-EPHS treatment, concentrations were 1,000, 2,000, 3,000, and 4,000 mg chemical oxygen demand?(COD)?L^?1 and cycle lengths were 6 and 8 h. The applied volumetric organic loads were 2.15, 4.74, 5.44, and 8.22 g COD L^?1 day^?1. For AR-EPHG treatment, concentration of 4,000 mg COD L^?1 and 4-h cycle length (7.21 g COD L^?1 day^?1) were used. For AR-S treatment, concentration was 4,000 mg COD L^?1 day^?1 and cycle lengths were 8 (7.04 g COD L^?1 day^?1) and 12 h (4.76 g COD L^?1 day^?1). The condition of 8.22 g COD L^?1 day^?1 (AR-EPHS) showed the best performance with respect to the following parameters: applied volumetric organic load of 7.56 g COD L^?1 day^?1, yield between produced methane and removed organic material of 0.016 mol CH₄?g COD^?1, CH₄ content in the produced biogas of 85 %, and molar methane productivity of 127.9 mol CH₄?m^?3 day^?1. In addition, a kinetic study of the process confirmed the trend that, depending on the biodegradability characteristics of the wastewaters used, the two-step treatment (acidogenic for biohydrogen production and methanogenic for biomethane production) has potential advantages over the single-step process.