Molybdatophosphoric acid as an efficient catalyst for the catalytic and chemoselective oxidation of sulfides to sulfoxides using urea hydrogen peroxide as a commercially available oxidant

An efficient procedure for the chemoselective oxidation of alkyl (aryl) sulfides to the corresponding sulfoxides using urea hydrogen peroxide (UHP) in the presence of a catalytic amount of molybdatophosphoric acid at room temperature is described. The advantages of described method are: generality, high yield and chemoselectivity, short reaction time, low cost and compliment with green chemistry protocols

PCl5 as a mild and efficient catalyst for the synthesis of bis(indolyl)methanes and di-bis(indolyl)methanes

Phosphorus pentachloride (PCl5) can efficiently catalyze the condensation of indoles with aldehydes as well as ketones at room temperature to afford bis(indolyl)methanes and di-bis(indolyl)methanes in high yields and short reaction times. KEY WORDS: PCl5, bis(Indolyl)methane, di-bis(Indolyl)methane, Indole, Aldehyde, Ketone  Bull. Chem. Soc. Ethiop. 2008, 22(3), 453-458

Phospholipase A2 activity of the Persian Gulf upside-down jellyfish venom (Cassiopea andromeda)

Background: The venomous jellyfish Cassiopea andromeda can produce envenomation and different toxicological and biological effects by their nematocysts. The phospholipase A2 enzymes (PLA2) are toxic and induce various pharmacological effects including neurotoxicity, myotoxicity, and anticoagulant activities. The main aim of the current project was to screen the in vitro PLA2 activity of the C. andromeda crude venom. To better understand the experimental result; a molecular docking study was also performed. Materials and methods: The live specimens were collected from Nayband lagoon, by a trawl net, and separation of their tentacles was done according to Bloom 's et al., method. The PLA2 activity of crude venom was performed according to the acidimetric method of Tan and Tan. The lyophilized venom was subjected to Gas Chromatography/ Mass Spectroscopy, and the obtained structures were used for docking study against PLA2. The indoxam was considered as standard control. Results: The PLA2 activity of the jellyfish crude venom was 413 ±0.08 µmol/min/mg. Analysis of the crude venom detected seven compounds (i-vii) using GC-MS. Docking data was also confirmed the experimental results. According to the docking results, the highest affinity [-6.7 (kcal/mol)] was observed in the compound “Pregn-5-ene-3,11-dione, 17,20:20,21 bis [methylenebis(oxy)]-, cyclic 3-(1,2-ethane diyl acetal”. Conclusions: A high PLA2 level was found in the venom of C. andromeda. There was a good correlation between in vitro and in silico studies

Facile preparation of a nanostructured functionalized catalytically active organosalt

We report a novel nanostructured organosalt, based on sulfonic acid functionalized pyrazinium {[H-pyrazine–SO3H]Cl2} that was synthesized and characterized by several techniques including Fourier transform infrared (FT- IR) spectroscopy, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG) analysis, transmission electron microscopy (TEM), mass spectrometry (MS), proton NMR (1H NMR), carbon-13 NMR (13C NMR) and also electron diffraction (ED) patterns. Results proved that the unprecedented sulfonated pyrizinium organosalt is indeed nanostructured and highly crystalline as supported by TEM, ED and XRD studies, having an average nanoparticle size of 50 nm according to TEM micrographs. The novel nano- organocatalyst was proved to be an efficient catalyst in the synthesis of 1,2,4,5-tetrasubstituted imidazoles by a one-pot multi-component condensation of benzil, a broad range of aldehydes, primary amines and ammonium acetate at 90 °C under solvent-free conditions

Ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br): a green and neutral reaction media for the efficient, catalyst-free synthesis of quinoxaline derivatives

Quinoxaline derivatives were produced in excellent yields and short reaction times via the condensation of 1,2-diamines with 1,2-diketones in the neutral ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) under catalyst-free and microwave irradiation conditions

Synthesis of Benzo[b]pyrane Derivatives Using Supported Potassium Fluoride as an Efficient and Reusable Catalytic System

A highly efficient and simple procedure for the synthesis of 4H-benzo[b]pyrane derivatives is described. The reaction of 5,5-dimethylcyclohexane-1,3-dione or cyclohexane-1,3-dione with aromatic aldehydes and malononitrile using catalytic amount of alumina supported KF in reflux ethanol affords the title compounds in high to excellent yields and in short reaction times

JSCS–3962 Original scientific paper

acid as an efficient catalyst for the catalytic and chemoselective oxidation of sulfides to sulfoxides using urea hydrogen peroxide as a commercially available oxidan

The anti-Alzheimer potential of novel spiroindolin-1,2-diazepine derivatives as targeted cholinesterase inhibitors with modified substituents

Abstract In this study, a new series of spiro indolin-1,2-diazepine were designed, synthesized, and screened for their cholinesterase inhibitory activities. A novel, green, high-yielding approach was constructed to synthesize spiro indolin-1,2-diazepine derivatives through a cascade reaction of different isatins, malononitrile and 1,1-enediamines (EDAMs) via sequential four-component reactions to produce the target compounds with good to excellent yields. Next the inhibitory potencies of all derivatives were determined spectroscopically at 415 nm using the modified Ellman method. The results of the in vitro screening indicated that 5l with spiroindolin-1,2-diazepine core bearing 5-NO2 at R1 and 4-OH at R2 was the most potent and selective AChE inhibitor with an IC50 value of 3.98 ± 1.07 µM with no significant inhibition against BChE while 5j was the most active analog against both AChE and BChE enzymes. The structure–activity relationships suggested the variation in the inhibitory activities of derivatives was affected by different substitutions on the indolinone ring as well as the phenyl moiety. The enzyme kinetic studies of the most potent compound 5l at five different concentrations and acetylthiocholine substrate (0.1–1 mM) by Ellman's method revealed that it inhibited AChE in a mixed mode with a K i of 0.044 μM. A molecular docking study was performed via induced fit docking protocol to predict the putative binding interaction. It was shown that the moieties used in the initial structure design play a fundamental role in interacting with the enzyme's binding site. Further, molecular dynamics simulations with the Schrödinger package were performed for 5l in a complex with AChE and revealed that compound 5l formed the stable complex with the enzyme. The MTT toxicity assessments against the neuroblastoma cell line were executed, and no toxicity was seen for 5l under the tested concentrations

Solvent-Free Synthesis of 1,8-Dioxo-octahydroxanthenes and 14-Aryl-14H-dibenzo[a,j]xanthenes using Saccharin Sulfonic Acid as an Efficient and Green Catalyst

Saccharin sulfonic acid (SaSA) is utilized as a highly efficient, green and inexpensive sulfonic acid-containing catalyst for the following one-pot multi-component organic transformations: (i) the condensation of dimedone (2 eq.) with aromatic aldehydes (1 eq.) leading to 1,8-dioxo-octahydroxanthenes, and (ii) the reaction of 2-naphthol (2 eq.) with arylaldehydes (1 eq.) leading to 14-aryl-14H-dibenzo[a,j]xanthenes. In these protocols, the title compounds are produced in high to excellent yields and in relatively short reaction times under solvent-free conditions