Green synthesis and antibacterial evaluation of some new 1-aryl-3-(1-aryl-1<Emphasis Type="Italic">H</Emphasis>-[1,2,3]triazol-4-yl)-propenones

A new series of 1-aryl-3-(1-aryl-1H-[1,2,3]triazol-4-yl)propenones (6a–6j) was synthesized by condensation of substituted acetophenones (5a–5c) with substituted 1-aryl-1H-[1,2,3]triazole-4-carbaldehydes (4a–4d) in the presence of potassium hydroxide under conditions of grinding and microwave irradiation. All the newly synthesized compounds were characterized by the IR, NMR, and mass spectroscopic analyses and their antibacterial activity against gram-positive and gram-negative bacterial strains was evaluated. Among the compounds synthesized, better activity was exhibited by 6a, 6c, 6f, 6g, and 6i.     

Synthesis and antiproliferative activity of 6,7-aryl/hetaryl coumarins

Two different series of novel analogs of 6,7-aryl/hetaryl coumarins 4a–4h and 8i–8l have been synthesized by using Suzuki–Miyara cross coupling reaction from 4-methyl-2-oxo-2H-chromen-7-yl trifluoro-methanesulfonate and 4-methyl-2-oxo-2H-chromen-6-yl trifluoromethanesulfonate in high yields (70–90%). All synthesized compounds were elucidated by means of IR, ¹H NMR, ¹³C NMR, and MS spectra. The synthesized compounds were tested for antiproliferative activity against different human cancer cell lines (SiHa, MDAMB-231, and PANC-1) and some of products demonstrated the distinctive effect.     

Furano compounds—IX

Starting with the appropriate 3-hydroxybenzoxanthones and the following the sequence of reactions allylation, Claisen migration, acetylation, bromine addition and dehydrobromination, 7:8-benzo- and 5:6-benzo-3:4, 2′:3′-furanoxanthones have been synthesized.     

Recent advances of boron-doped diamond electrochemical sensors toward environmental applications

The electrocatalytic properties of boron-doped diamond (BDD) electrodes have been considered for a variety of sensing applications. The unusual electrochemical properties of BDD include a large potential window, a small background current, and better resistance to fouling than other carbon-based electrodes. The use of BDD for remediation and environmental sensing applications has recently attracted the interest of the sensor research community. This review focuses on recent developments that involve the use of BDD as an environmentally friendly sensing material for environmental analysis. The electrochemical properties of boron-doped diamond that has undergone surface modification (e.g., with metals or enzymes) will be considered. Recent achievements involving the use of BDD electrodes for detecting pesticides, mycotoxins, peroxides, and phenolic compounds are considered.     

Analysis of thermal,oxidative and cold flow properties of methyl and ethyl esters prepared from soybean and mustard oils

Oilseed crop with high oil content and promising ecological adaptability are potential sources for competitive biodiesel production. This study investigates the scope of utilizing biodiesel development through the methyl and ethyl ester from soybean and mustard oil as an alternative fuel. Methyl and ethyl esters of oils having different fatty acids compositions such as soybean (SOME and SOEE) and mustard oil (MUME and MUEE) were prepared by transesterification with methanol and ethanol in the presence of an alkali-KOH catalyst. The gas chromatographic (GC) analysis of oil samples revealed that primary fatty acid composition in soybean oil was linoleic acid (C_18:2, 51.93%), followed by oleic acid (C_18:1, 22.82%), palmitic acid (C_16:0, 11.56%), linolenic acid (C_18:3, 5.95%) and stearic acid (C_18:0, 4.32%). Whereas, the main components in mustard oil were erucic acid (C_22:1, 32.81%), oleic acid (C_18:1, 24.98%), eicosenoic acid (C_20:1, 10.44%), linolenic acid (C_18:3, 8.61%) and palmitic acid (C_16:0, 2.80%). The physicochemical properties (acid value, iodine value, calorific value, flash point, pour point etc.) of methyl and ethyl ester samples were estimated and found to be within the acceptable range of ASTM D6751 standards specifications. The prepared esters and oil samples were examined for cold flow properties by differential scanning calorimetry (DSC). Results revealed better cold flow properties for MUME (−2.55 °C) and MUEE (−3.10 °C) than SOME (3.21 °C) and SOEE (1.83 °C) due to more unsaturated fatty acid content in MU. Thermal and oxidative stability of samples was determined by thermogravimetric analysis (TG) and differential thermal analysis (DTA). The thermal and oxidative stability ranking of the samples was in the order of oil > methyl esters > ethyl esters.

     

A tandem synthesis of 3-aroylcoumarinoflavones catalyzed by <Emphasis Type="SmallCaps">l</Emphasis>-proline and their antioxidant activity

A facile, convenient, efficient and high-yielding synthesis of 3-aroylcoumarinoflavones has been developed by the condensation of easily synthesized 7-hydroxy-8-formylflavones and benzoyl acetonitriles in the presence of catalytic amount of l-proline in ethanol reflux. All the synthesized compounds were evaluated for their antioxidant activity. Some of the compounds showed very good activity compared to standard BHT.     

Radiosynthesis of [18F]flumazenil for imaging benzodiazepine receptors and its evaluation in human volunteers using simultaneous PET-MRI

Journal of Radioanalytical and Nuclear Chemistry - Fluorine-18 (18F) flumazenil (FMZ) was synthesized and purified using a single solid-phase cartridge and the formulation was tested in animals for...     

MHD heat and mass transfer stagnation point nanofluid flow along a stretching sheet influenced by thermal radiation

Journal of Thermal Analysis and Calorimetry - The objective of the present study seems to be to explore the numerical findings of the steady incompressible 2-D MHD stagnation point flow of...     

High speed sub-micrometric microscopy using optical polymer microlens

We report the high speed scanning submicronic microscopy （SSM） using a low cost polymer microlens integrated at the extremity of an optical fiber. These microlenses are fabricated by a free-radical photopolymerization method. Using a polymer microlens with a radius of curvature of 250 nm, a sub-micrometric gold pattern is imaged experimentally by SSM. Different distances between the tip and the sample are used with a high scanning speed of 200 cm/s. In particular, metallic absorption contrasts are described with an optical spatial resolution of 250 nm at the wavelength of 532 nm. Moreover, finite-difference time-domain （FDTD） simulations concerning the focal lengths of microlenses with different geometries and heights support the experimental data.     

Triton B–Mediated Mild,Convenient, and Efficient Method for the Selective Alkylation of Cyclic Secondary Amines and Thiols

Alkylation of cyclic secondary amines, thiols, and pyridazinones has been demonstrated with alkyl halides using Triton B as base and reaction medium.