cis-[6-(Pyridin-2-yl)-1,3,5-triazine-2,4-diamine](dichloride) Palladium(II)-Based Electrolyte Membrane Reactors for Partial Oxidation Methane to Methanol.

Methane is an abundant resource and the main constituent of natural gas. It can be converted into higher value-added products and as a subproduct of electricity co-generation. The application of polymer electrolyte reactors for the partial oxidation of methane to methanol to co-generate power and chemical products is a topic of great interest for gas and petroleum industries, especially with the use of materials with a lower amount of metals, such as palladium complex. In this study, we investigate the ideal relationship between cis-[6-(pyridin-2-yl)-1,3,5-triazine-2,4-diamine(dichloride)palladium(II)] (Pd-complex) nanostructure and carbon to obtain a stable, conductive, and functional reagent diffusion electrode. The physical and structural properties of the material were analyzed by Fourier transform infrared (FT-IR) and Raman spectroscopies, transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques. The electrocatalytic activity studies revealed that the most active proportion was 20% of Pd-complex supported on carbon (m/m), which was measured with lower values of open-circuit and power density but with higher efficiency in methanol production with reaction rates of r = 4.2 mol L-1·h-1 at 0.05 V.

Alcoholic beverages from araçá-boi fruit: quantification of antioxidant compounds by NMR ERETIC2.

Fermentation is a preservation process responsible for increasing food product shelf life. In this context, alcoholic fermentation can add value to unconventional Amazon fruits, e.g., araçá-boi (Eugenia stipitata). This fruit has various antioxidant phenolic compounds with well-known nutraceutical properties. However, araçá-boi is still underexplored by food industry. This rationale led to investigate the influence of five commercial yeasts (Saccharomyces cerevisiae) and filtration process on chemical composition and antioxidant capacity of araçá-boi beverages. DPPH and Folin Ciocalteu assays were used to determine antioxidant capacity and total phenolic content. Organic compounds' contents were assessed by NMR-ERETIC2. In all beverages, ten compounds [tyrosol, sucrose, fructose, (α/ß)-glucose, ethanol, malic, citric, gallic, and succinic acids] were identified and quantified. The highest phenolic concentrations [gallic acid (390.0 µM) and tyrosol (380.0 µM)] were found in Biolievito Bayanus (BBA) beverage. The new BBA beverage was used for investigating filtration process influence on chemical composition and antioxidant responses. Alcoholic content (unfiltered: 13.9°GL and filtered: 12.7°GL), antioxidant responses, and total phenolic contents were influenced by filtration process. The yeast type and unfiltered process were determinant for chemical content and antioxidant capacity of beverages. These results might be useful to private sector and future production and commercialization of araçá-boi beverages.

Conversion of Methane into Methanol Using the [6,6'-(2,2'-Bipyridine-6,6'-Diyl)bis(1,3,5-Triazine-2,4-Diamine)](Nitrato-O)Copper(II) Complex in a Solid Electrolyte Reactor Fuel Cell Type.

The application of solid electrolyte reactors for methane oxidation to co-generation of power and chemicals could be interesting, mainly with the use of materials that could come from renewable sources and abundant metals, such as the [6,6'- (2, 2'-bipyridine-6, 6'-diyl)bis (1,3,5-triazine-2, 4-diamine)](nitrate-O)copper (II) complex. In this study, we investigated the optimal ratio between this complex and carbon to obtain a stable, conductive, and functional reagent diffusion electrode. The most active Cu-complex compositions were 2.5 and 5% carbon, which were measured with higher values of open circuit and electric current, in addition to the higher methanol production with reaction rates of 1.85 mol L-1 h-1 close to the short circuit potential and 1.65 mol L-1 h-1 close to the open circuit potential, respectively. This activity was attributed to the ability of these compositions to activate water due to better distribution of the Cu complex in the carbon matrix as observed in the rotating ring disk electrode experiments.

Pedra-ume caá fruit: An Amazon cherry rich in phenolic compounds with antiglycant and antioxidant properties.

Species of Eugenia have been used as an antidiabetic natural source. Chemical, antioxidant and antiglycant screening of extracts from pedra-ume caá (Eugenia punicifolia) fruits were performed. 1H NMR assisted by non-supervised chemometric methods were employed for the evaluation of the chemical profiles which were distinguished according to the color of fruit maturation stages, as well as for pulp and seed fruit. Furthermore, 1H NMR fingerprint analysis of the crude extract allowed the identification of quercitrin and myricitrin, beside other nine compounds. The extracts of the yellow (YP) and green (GP) pulps presented higher antiglycant and antioxidant activities. Fresh juice from E. punicifolia was encapsulated in microcapsules produced with dextrose equivalent (DE) of 10, 20 or 30 as wall materials for the maintainment of their antioxidant and antiglycant properties. The more efficient retention of the bioactive compounds was found using the DE30. The Encapsulation Efficiency (EE) and the Retention Efficiency (RE) of this system was found around 89.7% and 97.6%, respectively. In addition, NMR spectra revealed the presence of flavonoids O-glycosylated (quercitrin and myricitrin) which might be related to the antiglycant and antioxidant activities. The YP presented larger content of quercitrin (117.6 ±â€¯0.4 mg per each 100 g of fresh fruit). Therefore, pedra-ume caá should be employed as an alternative nutraceutical source, as well as intherapeutic pourposes.

Chemical characterization and antioxidant capacity of the araçá-pera (Psidium acutangulum): An exotic Amazon fruit.

The "araçá-pera" (Psidium acutangulum DC) is an exotic guava consumed by the Brazilian Amazon population. This paper describes 22 compounds from this fruit by UHPLC-HRMS and NMR methods, being one disaccharide, five monosaccharides, two organic acids, one trihydroxycinnamic acid glucopyranosyl, one tannine digalloyl glucopyranosyl, five triterpenoid acids, and six fatty acids. It also quantifies the level of ascorbic acid (AA) by HPLC-MS (74.32±1.23mg/100g of fresh fruit), and defines the chemical antioxidant activities by DPPH and ABTS+ assays (24.96±0.75, 90.57±0.63mg of vitamin C/100g fresh fruit, respectively), and a cell-based assays (76-100%). These results have shown that this exotic guava can be consumed as a nutraceutical ingredient, as well as be used in the production of functional foods in the Amazonian diet to prevent chronic and oxidative diseases.