Action of Organometallic Compounds on N-Cyanomethylimidate: New Synthetic Methode of Oxazole

The reaction of N-cyanomethylimidates with allylzinc bromide species has been examined. This reaction leads to the synthesis of oxazoles with good yields.     

Reaction of N-2-(1-Carbethoxy) - and N-2-(1-acyl)-benzimidazoimidates with Grignard Reagents. Synthesis of 1,3,5-Oxadiazino-(1,2-a)benzimidazoles

Reaction of ethyl chloroformate and acyl chlorides with iminoesters derived from 2- aminobenzimidazole, followed by Grignard reagent condensation leads to a variety of oxadiazinobenzimidazoles in good yield.     

Facile and Convenient Synthesis of 1‐Perfluoroalkyl‐1,2,4‐triazoles

Treatment of N‐methylcarbonyl 1, N‐phenylthioamido 2, and N‐cyano 3 iminoethers with perfluoroalkylated hydrazines leads to 1‐perfluoroalkyl‐5‐methyl‐1,2,4‐ triazoles, 4,1‐perfluoroalkyl‐5‐phenylamino‐1,2,4‐triazoles 5, and 1‐perfluoroalkyl‐5‐amino‐1,2,4‐triazoles 6 in good yields. These compounds are screened for their biological activities.     

Determination of Chromium (VI) in Airborne Particulate Matter by Electrothermal Atomic Absorption Spectrometry

Hexavalent chromium Cr(VI) is a well-established carcinogen associated with lung, nasal, and sinus cancer. Cr(VI) threshold limit values in workroom air have been recently lowered. Consequently, the currently available analytical methods are insufficiently sensitive or high cost. In this paper, a simple, cost-effective, sensitive, and reproducible method using solid-phase extraction with electrothermal atomic absorption spectrometry for determination of hexavalent chromium in airborne samples is reported. The method validation included selectivity, linearity, accuracy, and precision. Interferences from other ions likely to be present in airborne samples, including trivalent chromium, were tested and selectivity was demonstrated. The detection and quantification limits were, respectively, as low as 0.1 and 0.4?µg?L^?1. The linearity ranged from 0.5 to 50.0?µg?L^?1, with a regression coefficients exceeding 0.998. The extraction recovery exceeded 98%. The developed method was successfully compared with a reference spectrophotometric method. The performances achieved were similar to ion chromatography and high-performance liquid chromatography approaches. The novel method was tested on airborne samples collected from the workplace. The method’s performance suggests that it may be an alternative to high-cost techniques for monitoring occupational exposure to hexavalent chromium.     

Linear and Bilinear Multiplier Operators for the Dunkl Transform

The main purpose of this article is to study the L _p -boundedness of linear and bilinear multiplier operators for the Dunkl transform in the one dimensional case.     

Laser micro-machining of small objects for high-energy laser experiments

Targets for high-energy laser experiments are polymer or metal objects of small dimensions. These objects need high-precision processes (typical sizes of a few hundred micrometers with micrometer accuracy). In this paper, some targets for high-energy laser experiments obtained by picosecond Q-switched Nd:YAG laser and KrF excimer laser micro-machining are presented. All of the targets use an original process. Activities include cutting, drilling, and marking elements. A summary of targets made using laser processes will be presented.     

Chemosensing Properties of Coumarin Derivatives: Promising Agents with Diverse Pharmacological Properties,Docking and DFT Investigation

In this work, a three-component reaction of 3-acetyl-4-hydroxycoumarine, malononitrile, or cyanoacetate in the presence of ammonium acetate was used to form coumarin derivatives. The chemical structures of new compounds were identified by ¹H, ¹³C NMR and an elemental analysis. These compounds were examined in vitro for their antimicrobial activity against a panel of bacterial strains. In addition, these compounds were investigated for antioxidant activities by superoxideradical, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and hydroxyl radical scavenging assays, in which most of them displayed significant antioxidant activities. Furthermore, these compounds were evaluated for anti-inflammatory activity by indirect hemolytic and lipoxygenase inhibition assays and revealed good activity. In addition, screening of the selected compounds 2–4 against colon carcinoma cell lines (HCT-116) and hepatocellular carcinoma cell lines (HepG-2) showed that that 2-amino-4-hydroxy-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)nicotinonitrile 4 exhibited good cytotoxic activity against standard Vinblastine, while the other compounds exhibited moderate cytotoxic activity. Docking simulation showed that2-amino-4-hydroxy-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)nicotinonitrile 4 is an effective inhibitor of the tumor protein HCT-116. A large fluorescence enhancement in a highly acidic medium was observed, and large fluorescence quenching by the addition of traces of Cu²⁺ and Ni²⁺ was also remarked.     

Evaluation of Seven Essential Oils as Seed Treatments against Seedborne Fungal Pathogens of Cucurbita maxima

Essential oils are gaining interest as environmentally friendly alternatives to synthetic fungicides for management of seedborne pathogens. Here, seven essential oils were initially tested in vivo for disinfection of squash seeds (Cucurbita maxima) naturally contaminated by Stagonosporopsis cucurbitacearum, Alternaria alternata, Fusarium fujikuro, Fusarium solani, Paramyrothecium roridum, Albifimbria verrucaria, Curvularia spicifera, and Rhizopus stolonifer. The seeds were treated with essential oils from Cymbopogon citratus, Lavandula dentata, Lavandula hybrida, Melaleuca alternifolia, Laurus nobilis, and Origanum majorana (#1 and #2). Incidence of S. cucurbitacearum was reduced, representing a range between 67.0% in L. nobilis to 84.4% in O. majorana #2. Treatments at 0.5 mg/mL essential oils did not affect seed germination, although radicles were shorter than controls, except with C. citratus and O. majorana #1 essential oils. Four days after seeding, seedling emergence was 20%, 30%, and 10% for control seeds and seeds treated with C. citratus essential oil (0.5 mg/mL) and fungicides (25 g/L difenoconazole plus 25 g/L fludioxonil). S. cucurbitacearum incidence was reduced by ~40% for plantlets from seeds treated with C. citratus essential oil. These data show the effectiveness of this essential oil to control the transmission of S. cucurbitacearum from seeds to plantlets, and thus define their potential use for seed decontamination in integrated pest management and organic agriculture.