Synthesis and X‐Ray Analysis of a New [6]Helicene

A new disubstituted hexahelicene derivative 3 bearing methoxy functions at positions 3 and 14 has been prepared in racemic form through a Heck reaction followed by photocyclodehydrogenation. Suitable crystals of rac‐3 were analyzed by X‐ray crystallography and showed similar geometry to the structure of hexahelicene itself. Deprotection of 3 using boron tribromide led to 3,14‐dihydroxyhexahelicene 4 in quantitative yield. The complexation of transition metal atoms seemed to be quite possible by these two bidentate hexahelicene derivatives.     

Chemo- and Regioselective 1,3-Dipolar Cycloaddition of 2-Diazopropane over 1,4-Benzoquinone: Synthesis of New Pyrazoloquinones

Abstract

1,3-Dipolar cycloaddition reaction of 2-diazopropane 1 with 1,4-benzoquinone 2 carried out at ?20 °C led to a minor mono-cycloadduct 4 and mixture of bis-cycloadducts 6 and 7. The same addition realized with 3H-pyrazole 7 at ?60 °C for 2 h yields a mixture of compounds 8 and 9 and results in O-alkylation. The reaction of 3H-pyrazoles 4 and 7 with dimethylsulfoxide and oxalyl chloride under Swern conditions led to pyrazolenines 11 and 12.     

New Oxygenated Lignans from Kadsura philippinensis

Seven new oxygenated lignans, kadsuphilins G–M ( 1 – 7 , resp.), were isolated by chromatographic fractionation of an AcOEt extract of the aerial part of Kadsura philippinensis including four compounds with a dibenzocyclooctadiene skeleton, two with a bicyclooctane ring system, and one of 1,4‐biphenyldimethylbutane type. The structures of the isolated compounds were elucidated through extensive spectroscopic analyses, particularly 2D‐NMR experiments (HMQC, HMBC, and NOESY). The configuration of the chiral centers and the biphenyl moiety were determined by NOESY as well as CD spectroscopy, respectively.     

Evolution of ground state nuclear shapes in tungsten nuclei in terms of interacting boson model

The tungsten nuclei ^180–190W are investigated within the framework of the interacting boson model using an intrinsic coherent state formalism. The Hamiltonian operator contains only multipole operators of the subalgebra associated with the dynamical symmetries SU(3) and O(6). The study includes the behavior of potential energy surfaces (BES’s) and critical points in the space of the model parameters to declare the geometric character of the tungsten isotopic chain. Some selected energy levels and reduced E2 transition probabilities B(E2) for each nucleus are calculated to adjust the model parameters by using a computer code PH INT and simulated computer fitting programme to fit the experimental data with the IBM calculation by minimizing the root mean square deviations. The ^180–190W isotopes lies in shape transition SU(3)-O(6) region of the IBM such that the lighter isotopes comes very clare to the SU(3) limit, while the behavior ones tend to be near the γ-unstable O(6) limit.     

Synthesis,In Vitro α-Amylase Activity,and Molecular Docking Study of New Benzimidazole Derivatives

Russian Journal of Organic Chemistry - New benzimidazole derivatives were synthesized by reacting substituted phenacyl bromides with 1H-benzimidazole-2-thiols. The synthesized compounds were...     

Removal of nickel ions by adsorption on nano-bentonite: Equilibrium,kinetics, and thermodynamics

Nano-bentonite was used as an adsorbent to remove nickel ions from aqueous solutions. Experimental investigation was carried out to identify the effect of pH, contact time, initial concentration, and adsorbent dose of Ni(II). Equilibrium data were described by and fitted to Langmuir, Freundlich, and Dubinin–Radushkevich models. Results showed that the optimum conditions for the removal of the Ni(II) are initial concentration 100 mg/L, adsorbent dose 0.5 g, and pH 6. Surface morphology and functionality of nano-bentonite were characterized by SEM and FTIR. The kinetics data were more accurately described by pseudo-second-order model. The intra-particle diffusion model gave multi-linear curves, so more than one step controlled the adsorption process. Nano-bentonite removed nickel with maximum adsorption capacity of 39.06 mg/g (30°C, pH) and thermodynamic data indicated that adsorption reaction is spontaneous and of an endothermic nature.     

Synthesis,Kinetics, and Equilibrium Study of Highly Sensitive Colorimetric Chemosensor for Monitoring of Copper Ions based on Benzo[f]fluorescein Dye Derivatives

The colorimetric chemosensor 2‐((3,5‐dichloro‐2‐hydroxybenzylidene)amino)‐3′,6′‐dihydroxy‐6‐methyl‐4‐(p‐tolyl)spiro[benzo[f]isoindole‐1,9′‐xanthen]‐3(2H)‐one ( BFFSH ) derived from benzo[f]fluorescein dye was synthesized. NMR and IR spectroscopy as well as mass spectrometry were used to confirm the compound. BFFSH shows potential application for detecting metal ions in aqueous solution. It displays a colorimetric selectivity and sensitivity towards the aqueous solution of Cu²⁺ ions with a detection limit in the nano‐molar range (1.69 nM). In addition, the application of BFFSH was extended for the detection of Cu²⁺ ions in real water samples (tap and synthetic water) with a high recovery percentage. Additionally, the association constant (K_a) of BFFSH , which binds with Cu²⁺ ions based on 2:1 stoichiometry was calculated.     

New cytotoxic bio-transformed sesquiterpene by Rhizopus oryzae fungus

Due to the rapidly increasing number of pathogenic bacteria, viruses, and tumor cells that possess resistance toward established therapies, lead structures for the development of new drugs are in high demand. The plant material of Tanacetum sinaicum is considered a prolific source of the potent biologically active sesquiterpene Tanacetolide A ( 1 ). In our research, we focused on the structural transformation of the substrate Tanacetolide A (compound 1 ) by suspended culture of the novel locally isolated terrestrial fungus Rhizopus oryzae KX685359. The fungal transformation resulted in the formation of 1β,3α-dihydroxy-6α-hydroperoxy-eudsm-4(15)-ene 12-oic acid ( 2 ) with higher antiproliferative activity against colon cancer cell line (Caco-2) than that of the parent compound ( 1 ).     

Synthesis,characterization, and antimicrobial evaluation of some novel anthracene heterocycles derivatives

A series of novel heterocyclic compounds containing anthracene moiety was synthesized. Reaction of (11R,15S)-9,10-dihydro-9,10-[3,4]furanoanthracene-12,14-dione with 2-cyanoacetohydrazide gave 2-cyano-pyrroloanthracen acetamide (1) , which acts as an adaptable material for the synthesis of new heterocyclic compounds. The synthesized compounds were examined for their antimicrobial activity against Escherichia coli and Staphylococcus aureus via p-iodonitrotetrazolium violet formazon assay. The results exhibited great activity against the tested strains with a minimum bactericidal concentration range from 0.636 to 3.8 mg/mL) and 0.159 to 3.6 mg/mL for E coli and S aureus, respectively. Interestingly, the highest activity was recorded for chromene derivative (6) against both strains.     

Optimisation and characterisation of various extraction conditions of phenolic compounds and antioxidant activity in olive seeds

This study was conducted to optimise the extraction conditions of phenolic compounds to evaluate antioxidant extraction parameters and to identify the major free and bound phenolic compounds in olive seeds. The results obtained using methanol as an extraction solvent for olive seeds indicated that the optimised total phenolic content and antioxidant activity were obtained at an extraction time of 12 h, an extraction temperature of 70°C and an extraction cycle of three stages. The correlation coefficient between total phenolic compounds and antioxidant activities was positive (R2 = 0.83). The major finding is that the predominant phenolic compounds in olive seeds were present in free form. However, a small percentage of the bound phenolic compounds was found in olive seeds compared to that of the free phenolic compounds. This study recommends that olive seeds with optimised extraction conditions (i.e. optimised correlation between phenolic compound contents and antioxidant activities) can be used as potential food additive candidates in functional, nutraceutical and pharmaceutical industries.