Green one-pot synthesis of N -bisphosphonates as antimicrobial and antioxidant agents

A straightforward and greener approach has been developed for the synthesis of novel aminomethylene bisphosphonates by one-pot reaction of diverse aryl/heteroaryl amines with dialkyl phosphite and triethyl orthoformate using CuO nanoparticles as catalyst under microwave irradiation and solvent-free conditions. This is an ecofriendly synthetic approach for swift access to a library of diverse aminomethylene bisphosphonates. All the synthesized new compounds were evaluated for their antimicrobial activity by disc diffusion method and antioxidant activity by DPPH, H2O2, and NO methods. The title compounds exhibited significant antioxidant and considerable antimicrobial activities.     

Design and synthesis of diethyl(substituted 2-benzylbenzofuran-3-yl)phosphonates as antioxidant and antimicrobial agents

In continuance of our effort to improve novel and potent synthetic approaches for various bioactive phosphorylated heterocycles via C─P bond formation, a series of diethyl substituted(2-benzylbenzofuran-3-yl)phosphonate derivatives ( 4a - j ) was synthesized by one-pot reaction of various diversely substituted salicylaldehydes, phenyl acetylene, and diethyl phosphite using CuO nanoparticles as catalyst in 1:1 ethanol and water under room temperature. The new compounds have been studied for their radical scavenging activity by DPPH, H₂O₂, and NO approaches and antimicrobial activity assay against bacteria and fungi by disk diffusion method.     

Design,Synthesis, and Biological Evaluation of Fluoroquinolones Linked to 4-Thiazolidinone Moieties as Potent Antimicrobial Agents: Docking Analysis

Russian Journal of General Chemistry - A series of novel fluoroquinolone thiazolidinone derivatives were synthesized and evaluated for their biological activity. All the newly synthesized compounds...     

Unusual coordination mode of aroyl/acyl thiourea ligands and their π‐arene ruthenium (II) piano‐stool complexes: Synthesis,molecular geometry,theoretical studies and biological applications

Two mononuclear ruthenium complexes ( 1 and 2 ) with aroyl/acylthiourea as an ancillary ligand of type, [(η⁶‐p‐cymene)RuCl(L‐N,S)], where [ L1  = 2,4‐dichloro‐N‐(o‐tolylcarbamothioyl)benzamide] and L2  = N‐(phenylcarbamothioyl)cyclohexanecarboxamide] were synthesized and well characterized. The single crystal X‐ray diffraction studies revealed the coordination mode and the geometry of the complexes. The two complexes adopted general piano‐stool (three‐legged) geometry with a novel coordination mode of aroyl/acylthiourea through amide N (anionic) and thiocarbonyl S (neutral). This type of monobasic bidentate coordination of the aroyl/acylthiourea ligand was witnessed the first time around the metal ion. The coordination of the complexes was well explained through geometric parameters and frontier molecular orbital parameter values computed at the B3LYP/SDD level. The synthesized complexes were also screened for their antibacterial, antifungal, antioxidant and in vitro antiproliferative activities. Complexes exhibited good antimicrobial agents against various pathogens. The antioxidant activity of the complex 2 has shown most potent activity with IC₅₀ value of 48.55 ± 1.7 μM compared to the reference drug. In addition, the in vitro antiproliferative activity of the complex 2 showed excellent activity against HepG‐2 cell line with the IC₅₀ value of 24.30 ± 1.20 μM which is close to Doxorubicin standard drug.     

Surface characterization and London dispersive surface free energy of functionalized single-walled carbon nanotubes with a blend of polytetrafluoroethylene by inverse gas chromatography

The SWCNTs and SWCNT-polytetrafluoroethylene (PTFE) blend were prepared by using simple reaction mixture in the presence of chromosorb (SiO₂). Surface morphology of SWCNTs and (SWCNT-PTFE) blend was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and surface BET analysis. In addition, the surface thermodynamic properties of n-alkanes and polar probe net retention volumes are measured by inverse gas chromatography (IGC). The London dispersive surface free energy values were found to be decreased linearly with increase of temperature. The specific component of the surface free energy of adsorption for the polar probes was obtained using the Donnet-Park method. The surface character “S” value (K_b/K_a) at SWCNTs was found to be 0.74, and SWCNT-PTFE blend surface character value was found to be 0.86. This result demonstrates that the (SWCNT-PTFE) blend surface contains relatively more acidic sites then that of SWCNT surface. Therefore, the IGC results provide useful complementary information on the (SWCNT-PTFE) blend surface.     

A Highly Fluorescent Pyrene-Based Sensor for Selective Detection Of Fe3+ Ion in Aqueous Medium: Computational Investigations

In this work, we introduce a highly selective and sensitive fluorescent sensor based on pyrene derivative for Fe(III) ion sensing in DMSO/water media. 2-(pyrene-2-yl)-1-(pyrene-2-ylmethyl)-1H-benzo[d]imidazole (PEBD) receptor was synthesized via simple condensation reaction and confirmed by spectroscopic techniques. The receptor exhibits fluorescence quenching in the presence of Fe(III) ions at 440 nm. ESI–MS and Job’s method were used to confirm the 1:1 molar binding ratio of the receptor PEBD to Fe(III) ions. Using the Benesi-Hildebrand equation the binding constant value was determined as 8.485?×?10³ M^?1. Furthermore, the limit of detection (LOD, 3σ/K) value was found to be 1.81 µM in DMSO/water (95/5, v/v) media. According to the Environmental Protection Agency (EPA) of the United States, it is lower than the acceptable value of Fe³⁺ in drinking water (0.3 mg/L). The presence of 14 other metal ions such Co²⁺, Cr³⁺, Cu²⁺, Fe²⁺, Hg²⁺, Pb²⁺, K⁺, Ni²⁺, Mg²⁺, Cd²⁺, Ca²⁺, Mn²⁺, Al³⁺, and Zn²⁺ did not interfere with the detection of Fe(III) ions. The fluorescence life-time of the receptor PEBD with and without Fe³⁺ ion was found to be 1.097?×?10^?9 s and 0.9202?×?10^?9 s respectively. Similarly, the quantum yield of the receptor PEBD with Fe³⁺ and without Fe³⁺ ion was calculated, and found as 0.05 and 0.25 respectively. Computational studies of the receptor PEBD were carried out with density functional theory (DFT) using B3LYP/ 6-311G (d, p), LANL2DZ level of theory.

Graphical Abstract

     

A novel synthetic approach to 4-acetamido-1-arylindazoles via Semmler–Wolff rearrangement of 1-aryl-6,7-dihydro-5H-indazol-4-one oxime

A simple and efficient procedure for the syntheses of 4-acetamido-1-arylindazoles from corresponding 1-aryl-6,7-dihydro-5H-indazol-4-one oximes by Semmler–Wolff aromatization using acetic anhydride and sodium iodide is reported.     

Semmler–Wolff aromatisation: a concise route for the synthesis of 5-amino-quinazolines and 4-amino-indoles

A simple and efficient methodology for the synthesis of 5-amino-quinazolines and 4-amino-indoles via Semmler–Wolff aromatisation reaction has been carried out. The oximation of keto intermediates followed by Semmler–Wolff aromatisation using acetic anhydride and a catalytic amount of sodium iodide in xylene provided the desired quinazolines and indoles.     

Synthesis of New 4,5-Dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-amine–Derived Ureas and Their Anticancer Activity

A new series of 1,2,4-triazolo[4,3-a]-quinoline derivatives were designed and synthesized to meet the structural requirements essential for anticancer activity. N-1-(5-Methylisoxazol-4-yl/4-fluoro-2,3-dihydro-1H-inden-1-yl/aryl)-N’-3-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-yl) urea derivatives were accomplished in good yields by the reaction of 4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-amine with 3-(3-chloro-5-fluoro-2-methoxyphenyl)-5-methyl-isoxazole-4-carboxylic acid, 4-fluoro-2,3-dihydro-1H-indene-1-carboxylic acid, and various simple aromatic carboxylic acids in the presence of diphenyl phosphoryl azide (DPPA). All the newly synthesized title compounds were characterized by elemental and spectral data. Furthermore, anticancer activity was screened for the title compounds (12a–j) in vitro against human neuroblastoma cell lines (SK N SH) and human colon carcinoma cell lines (COLO 205) by using the MTT cell viability method. A few of them (12a and 12b) possess significant cytotoxicity, and some other compounds 12d-f and 12j displayed moderate cytotoxicity against both cell lines.