Sequential enzymatic procedure for the preparation of enantiomerically pure 2-heteroaryl-2-hydroxyacetic acids

Starting from the racemic 2-benzofuranyl- and 2-benzo[b]thiophenyl-2-hydroxyacetic acid ethyl esters as substrates, a general method was developed for the efficient synthesis of the corresponding highly enantiomerically enriched (ee up to 99%) (R)- and (S)-2-heteroaryl-2-hydroxyacetic acids.     

Recent development of heterogeneous catalysis in ring-opening,biocatalysis, and selective partial oxidation reactions on metal oxides

In this review article, we analyze the state of the art and future developments in three important domains of heterogeneous catalysis, namely ring opening, biocatalysis, and partial oxidation on metal oxides. After recollecting the scientific bases of each domain, we consider several examples, some recent improvements/developments, and some prospective views.     

Statu quo sur la méthanation du dioxyde de carbone : une revue de la littérature

This review summarizes the statu quo and the perspectives of chemical methanation. CO₂ methanation, including catalyst deactivation, reactors, mechanisms, and thermodynamics are presented. This reaction serves as a test bed for our fundamental understanding of heterogeneous catalysis and is used in various industrial processes, including the removal of oxo-compounds (CO_x) in the feed gas for the ammonia synthesis, in connection with the gasification of coal, where it can be used to produce methane from synthesis gas, and in relation to Fischer–Tropsch's synthesis. Moreover, CO₂ methanation became of interest as a renewable energy storage system based on a “power-to-gas” conversion process by SNG (synthetic natural gas) production integrating water electrolysis and CO₂ methanation as a highly effective way to store the energy produced by renewables sources. The effectiveness and efficiency of the “power-to-gas” plants strongly depends on the CO₂-methanation process.     

Characterization of the Phenolics and Free Radical Scavenging of Romanian Red Wine

The goal of the present work was to study the influence of winemaking procedures and the effect of bottle-aging on the antioxidant activity and on the variation of low molecular weight phenolics of Feteasca Neagra and Negru Aromat red wine from the Valea Calugareasca vineyard, Romania. The free radical-scavenging activity was measured using the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical from bottles sampled every 3 months up to the 9th month. The results indicated that Negru Aromat obtained by classical maceration had the highest activity at 6th month. The high-performance liquid chromatography results showed that the most abundant low molecular weight phenolic compounds were catechin, (?)-epicatechin, gallic acid, malvidin, and peonidin 3-O-glucoside. For the phenolics, Feteasca Neagra prepared by classical maceration and Negru Aromat by run-off juice were the richest. For anthocyanidins, the Feteasca Neagra and Negru Aromat wine by classical maceration had the highest concentrations. These results suggest that classical maceration is the winemaking procedure of choice to obtain the highest quality wine from the Valea Calugareasca vineyard.     

Elemental Analysis and Metal Intake of Romanian Vegetables

ABSTRACT

Inductively coupled plasma-mass spectrometry multielemental profiling was performed to determine eight elements in 54 vegetable samples. The range of concentrations of Fe and Ni was 1.91?±?0.09 to 443.31?±?22.32?mg/kg and 0.05?±?0.004 to 16.36?±?0.36?mg/kg, respectively. The concentrations of Pb and Cd were up to 1.56?±?0.04 and 0.78?±?0.04?mg/kg, respectively. Some samples exceeded the maximum admissible limits imposed by national and international regulations. The mean concentrations of Mn and Cu were between 20.93?±?0.43 and 13.98?±?0.30?mg/kg in tomatoes and 20.60?±?0.53 and 11.25?±?0.22?mg/kg in peppers. For the evaluation of health risk related to the consumption of vegetables, the daily intake rate, target hazard quotient (THQ), and hazard index were evaluated. The daily intakes were low and correspond to 2 to 14% of the tolerable daily values established by legislation. The results showed that the THQ and hazard index for the metals were lower than 1, indicating that the vegetable ingestion does not represent a significant risk for consumer health. Analysis of variance revealed that Zn may be used as a species-specific marker (p?=?0.026). Principal component analysis extracted three main components, explaining a total variance of 72.49% and grouped all determined elements.     

Characterization of Vegetables by Stable Isotopic and Elemental Signatures

ABSTRACT

109 Romanian parsley, celery and parsnip root, cucumber, vegetable marrow, onion, and pepper samples were characterized by their stable isotope ratios and elemental concentrations in comparison to imported varieties. Organic and conventional agriculture practices were also compared as well as a differentiation between eggplant and peppers grown in greenhouses and those in the field. δ²H values were between ?70.8 and 5.6‰, while the δ¹⁸O values were between ?9.0 and 4.1‰. The δ¹⁵N values for white onions were from 2.8 to 11.1‰. For Romanian organic onions, the carbon isotopic values were lower (?29.2 to ?28.2‰) compared to conventional onions from other countries (?27.8‰ to ?23.8%). Linear discriminant analysis was used to characterize agricultural practices and the geographic origin of the vegetables.     

Melissa officinalis L. Aqueous Extract Exerts Antioxidant and Antiangiogenic Effects and Improves Physiological Skin Parameters

Melissa officinalis (MO) is a medicinal plant well-known for its multiple pharmacological effects, including anti-inflammatory, anticancer and beneficial effects on skin recovery. In this context, the present study was aimed to investigate the in vitro and in vivo safety profile of an MO aqueous extract by assessing cell viability on normal (HaCaT—human keratinocytes) and tumor (A375—human melanoma) cells and its impact on physiological skin parameters by a non-invasive method. In addition, the antioxidant activity and the antiangiogenic potential of the extract were verified. A selective cytotoxic effect was noted in A375 cells, while no toxicity was noticed in healthy cells. The MO aqueous extract safety profile after topical application was investigated on SKH-1 mice, and an enhanced skin hydration and decreased erythema and transepidermal water loss levels were observed. The in ovo CAM assay, performed to investigate the potential modulating effect on the angiogenesis process and the blood vessels impact, indicated that at concentrations of 100 and 500 µg/mL, MO aqueous extract induced a reduction of thin capillaries. No signs of vascular toxicity were recorded at concentrations as high as 1000 μg/mL. The aqueous extract of MO leaves can be considered a promising candidate for skin disorders with impaired physiological skin parameters.     

Y2O3 Nanoparticles and X-ray Radiation-Induced Effects in Melanoma Cells

The innovative strategy of using nanoparticles in radiotherapy has become an exciting topic due to the possibility of simultaneously improving local efficiency of radiation in tumors and real-time monitoring of the delivered doses. Yttrium oxide (Y₂O₃) nanoparticles (NPs) are used in material science to prepare phosphors for various applications including X-ray induced photodynamic therapy and in situ nano-dosimetry, but few available reports only addressed the effect induced in cells by combined exposure to different doses of superficial X-ray radiation and nanoparticles. Herein, we analyzed changes induced in melanoma cells by exposure to different doses of X-ray radiation and various concentrations of Y₂O₃ NPs. By evaluation of cell mitochondrial activity and production of intracellular reactive oxygen species (ROS), we estimated that 2, 4, and 6 Gy X-ray radiation doses are visibly altering the cells by inducing ROS production with increasing the dose while at 6 Gy the mitochondrial activity is also affected. Separately, high-concentrated solutions of 25, 50, and 100 µg/mL Y₂O₃ NPs were also found to affect the cells by inducing ROS production with the increase of concentration. Additionally, the colony-forming units assay evidenced a rather synergic effect of NPs and radiation. By adding the NPs to cells before irradiation, a decrease of the number of proliferating cell colonies was observed with increase of X-ray dose. DNA damage was evidenced by quantifying the γ-H2AX foci for cells treated with Y₂O₃ NPs and exposed to superficial X-ray radiation. Proteomic profile confirmed that a combined effect of 50 µg/mL Y₂O₃ NPs and 6 Gy X-ray dose induced mitochondria alterations and DNA changes in melanoma cells.