Synthesis and Antimicrobial Evaluation of Newly Synthesized N,S‐Bisphosphonate Derivatives

An easy strategy for the synthesis of tetraethyl‐2‐(3‐mercapto‐4H‐1,2,4‐triazol‐4‐ylamino)‐2‐(aryl)ethane‐1,1‐diyldiphosphonate and tetraethyl‐(6‐(aryl)‐5,6‐dihydro[1,2,4]triazolo[3,4‐b]‐[1,3,4]thiadiazol‐6‐yl)methylenediphosphonate derivatives with reasonable 67–85% overall yields has been developed. The approach was achieved via applying Wadsworth–Horner–Emmons reagent, tetraethylmethylenebisphosphonate, to 4‐(arylideneamino)‐4H‐1,2,4‐triazole‐3‐thiols under phase‐transfer catalysis conditions. Screening results of antimicrobial potency for 12 out of 17 methylene‐1,1‐bisphosphonate products were reported. Two of the tested thiadiazolomethylenebisphosphonates displayed better spectrum of antimicrobial activity against the pathogens, compared with that of the positive controls.     

Effect of iron poly(acrylic acid-co-acrylamide) and melamine polyphosphate on the flammability properties of linear low-density polyethylene

Journal of Thermal Analysis and Calorimetry - This research is exhibited to visualize the squeezed flow of magneto-nanoliquid between two parallel disks. Transportations of heat and mass are...     

An efficient synthesis of an 8-phenoxy aporphine derivative utilizing mono-ligated palladium ortho-phenol arylation

8-Aryloxy aporphines are a structurally diverse subset of alkaloids that display an array of biological activities. An efficient synthesis of an 8-phenoxy aporphine model compound has been developed utilizing Pictet-Spengler cyclization followed by biaryl bond formation using Pd-XPhos catalyzed ortho-phenol arylation. Biaryl bond formation using direct arylation is also compared. Finally, the stability of the 8-phenoxy aporphine model compound is discussed with potential implications for the isolation, structure elucidation and pharmacognosy of 7-dehydroaporphine natural products.     

Validated Optimized Method for Simultaneous Analysis of Active Silymarin Components and Dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethylene Dioxybiphenyl-2,2′-dicarboxylate in a Pharmaceutical Preparation by Use of a Monolithic Silica C18 Column

A simple, rapid, and sensitive isocratic reversed-phase LC method using a monolithic column has been developed and validated for simultaneous analysis of the active components of silymarin [taxifolin, silydianin, silychristin, diastereomers of silybin (silybin A and B), and diastereomers of isosilybin (isosilybin A and B)] and dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethylene dioxybiphenyl-2,2′-dicarboxylate in a commercial formulation. The mobile phase was a 45:55 (v/v) mixture of methanol and 5 mM NaH₂PO₄ (adjusted to pH 2.75 with phosphoric acid) at a flow rate of 1.5 mL min^?1. UV detection was performed at 288 nm and quantification was based on peak area. The method was validated for linearity, accuracy, precision, selectivity, and robustness.     

Catalytic properties of the polyoxometalate [Ti2(OH)2As2W19O67(H2O)]8? in selective oxidations with hydrogen peroxide

The catalytic properties of the sandwich polyoxometalate [Ti₂(OH)₂As₂W₁₉O₆₇(H₂O)]⁸⁻, which contains two (B-α-As^IIIW₉O₃₃) fragments linked together by a “belt” consisting of one octahedral WO(H₂O)⁴⁺ and two square-pyramidal Ti(OH)³⁺ groups, have been investigated in the selective liquid-phase oxidation of organic compounds by aqueous hydrogen peroxide. The polyoxometalate shows high catalytic activity and selectivity in the oxidation of alkenes, alcohols, diols, and thioethers. The composition of the reaction products indicates that hydrogen peroxide is activated via a heterolytic mechanism.     

Tracking traces of transition metals present in concrete mixtures by inductively-coupled plasma mass spectrometry studies

Transition metals can have a significant impact in research related to the dosage optimization of superplasticizers. It is known that the presence of transition metals can influence such doses, and the application of a contemporary instrumental method to obtain the profiles of subsisting transition elements in concrete mixtures would be useful. In this work, inductively-coupled plasma mass spectrometry (ICP-MS) is investigated as a possible tool to track traces of transition metals in concrete mixtures. Depth profiling using ICP-MS on proofed and unproofed concrete shows the presence of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn at trace intensities in the bulk of the samples under investigation. The study demonstrates that the transition metals present in the concrete sample are largely a part of the cement composition and, to a minor degree, a result of exposure to the seawater after curing. The coated concrete samples have a metal distribution pattern similar to the uncoated samples, but slight differences in intensity bear testimony to the very low levels that originate from the exposure to seawater. While X-ray diffraction fails to detect these traces of metals, ICP-MS is successful in detecting ultra-trace intensities to parts per trillion. This method is not only a useful application to track traces of transition metals in concrete, but also provides information to estimate the pore size distribution in a given sample by very simple means.     

Hepatoprotective constituents of Torilis radiata Moench (Apiaceae)

An investigation of the aqueous ethanolic extract (AE) of the aerial parts of Torilis radiata Moench yielded two triterpenes (lupeol acetate (1) and α-amyrin (2)), a sterol (spinasterol (3)) from its n-hexane fraction (HF), a flavone (acacetin (4)), a coumarin (scopoletin (5)), a phenolic acid (ferulic acid (6)) from the chloroform fraction (CF) and a flavone glycoside (luteolin-7-O-glucoside (7)) from the n-butanol fraction (BF). The hepatoprotection of the AE and its fractions was assessed in terms of the reduction in histological damage, accompanied by restoration of the liver enzymes (alanine amino transferase (ALT), aspartate amino transferase (AST), lactate dehydrogenase (LDH)), a reduction in the inflammatory markers (tumour necrosis-α (TNF-α), nitric oxide (NO), N-acetyl-β-D-glucosaminidase (NAG) and myloperoxidase (MPO) in serum) and restoration of the oxidant balance by decreasing the serum and hepatic malondialdehyde (MDA) levels, along with increasing the activity of hepatic catalase (CAT), glutathione peroxidase (GSHPx) and the non-enzymatic antioxidant glutathione (GSH).