12,940 results match your criteria phenyl ring

Unmasking Steps in Intramolecular Aromatic Hydroxylation by a Synthetic Nonheme Oxoiron(IV) Complex.

Angew Chem Int Ed Engl 2021 Jul 22. Epub 2021 Jul 22.

University of Minnesota Twin Cities Campus: University of Minnesota Twin Cities, Chemistry, UNITED STATES.

In this study, a methyl group on the classic tetramethylcyclam (TMC) ligand framework is replaced with a benzylic group to form the metastable [Fe IV (O syn )(Bn3MC)] 2+ ( 2 - syn ; Bn3MC = 1-benzyl-4,8,11-trimethyl-1,4,8,11-tetraazacyclotetradecane) species at -40 °C. The decay of 2 - syn with time at 25 °C allows the unprecedented monitoring of the steps involved in the intramolecular hydroxylation of the ligand phenyl ring to form the major Fe III -OAr product 3 . At the same time, the Fe II (Bn3MC) 2+ ( 1 ) precursor to 2 - syn is re-generated in a 1:2 molar ratio relative to 3 , accounting for the first time for all the electrons involved and all the Fe species derived from 2 - syn as shown in the following balanced equation. Read More

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New phosphorescent iridium(III) dipyrrinato complexes: synthesis, emission properties and their deep red to near-infrared OLEDs.

Dalton Trans 2021 Jul 21. Epub 2021 Jul 21.

Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University (PolyU), Hong Kong, China. and PolyU Shenzhen Research Institute, Shenzhen 518057, China and Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Hong Kong, China.

A series of heteroleptic Ir(iii) complexes composed of two cyclometalated C^N ligands and one dipyrrinato ligand used as an ancillary ligand are synthesized and characterized. With the introduction of a fluorine atom, phenyl ring or diphenylamino group into both C^N ligands and by keeping the ancillary ligand unchanged, these Ir(iii) dipyrrinato phosphors do not show an obvious shift in their emission bands. They exhibit emissions extending well into the near-infrared region with an intense band located at around 685 nm in both photo- and electroluminescence spectra, and the deep red to near-infrared organic light emitting diodes (OLEDs) based on them afforded a maximum external quantum efficiency of 2. Read More

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Marmoset glutathione transferases with ketosteroid isomerase activity.

Biochem Biophys Rep 2021 Sep 12;27:101078. Epub 2021 Jul 12.

Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, SE-10691, Stockholm. Sweden.

The common marmoset encodes two glutathione transferase (GST) enzymes with ketosteroid double-bond isomerase activity. The most active enzyme is CjaGST A3-3 showing a specific activity with 5-androsten-3,17-dione (Δ-AD) of 62.1 ± 1. Read More

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September 2021

Discovery of Alkoxy Substituted Novel Sulfonylurea Compounds That Display Strong Herbicidal Activity against Monocotyledon Grasses.

J Agric Food Chem 2021 Jul 20. Epub 2021 Jul 20.

State-Key Laboratory and Research Institute of Elemento-Organic Chemistry, National Pesticide Engineering Research Center, College of Chemistry, Nankai University, Tianjin 300071, China.

In the present study, we have designed and synthesized a series of 42 novel sulfonylurea compounds with alkoxy substitutions at the phenyl ring and evaluated their herbicidal activities. Some target compounds showed excellent herbicidal activity against monocotyledon weed species. When applied at 7. Read More

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Structure-activity relationships of natural quinone vegfrecine analogs with potent activity against VEGFR-1 and -2 tyrosine kinases.

J Antibiot (Tokyo) 2021 Jul 20. Epub 2021 Jul 20.

Institute of Microbial Chemistry (BIKAKEN), Tokyo, Japan.

A series of analogs of vegfrecine, a natural quinone vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor, was synthesized via oxidative amination of 2,5-dihydroxybenzamide with functionalized arylamine followed by ammonolysis and substitution of the quinone ring. The inhibitory activities of the analogs against the VEGFR-1 and -2 tyrosine kinases were assayed in vitro with the aim to identify a compound suitable to treat cancer and inflammatory diseases. Alterations of the functionality of the phenyl group, substitution of the quinone ring, and oxidative cyclization of the 1-carboxamide-2-aminoquinone moiety to form an isoxazole quinone ring were examined. Read More

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Synthesis and Biological Evaluation of Tetrahydropyrimidine and Dihydropyridine Derivatives Against Leishmania Major.

Acta Parasitol 2021 Jul 19. Epub 2021 Jul 19.

Department of Medicinal Chemistry, School of Pharmacy, Ardabil University of Medical Sciences, 5618953141, Ardabil, Iran.

Purpose: A number of tetrahydropyrimidines and their bioisosteric dihydropyridines bearing chloro substituent at various positions of phenyl ring in C4 of main scaffolds were designed, synthesized and evaluated for antileishmanial activity.

Methods: The antileishmanial activity of the synthesized compounds was evaluated against promastigote and amastigote forms. Moreover, molecular docking studies of the compounds in pteridine reductase 1 (PTR1) pocket were carried out to describe the results of biological experiments. Read More

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Synthesis of New 1-1,2,3-Triazole Analogs in Aqueous Medium "" Chemistry: A Novel Class of Potential Carbonic Anhydrase-II Inhibitors.

Front Chem 2021 30;9:642614. Epub 2021 Jun 30.

Natural and Medical Sciences Research Center, University of Nizwa, Nizwa, Oman.

A series of novel 1-1,2,3-triazole analogs () were synthesized chemistry and Suzuki-Miyaura cross-coupling reaction in aqueous medium. The compounds were evaluated for their carbonic anhydrase-II enzyme inhibitory activity . The synthesis of triazole was accomplished using ()-(-) ethyl lactate as a starting material. Read More

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Preparation of new spiropyrazole, pyrazole and hydantoin derivatives and investigation of their antioxidant and antibacterial activities.

Chem Biodivers 2021 Jul 17. Epub 2021 Jul 17.

University of Mazandaran, Organic Chemistry, air way, Babolsar, IRAN (ISLAMIC REPUBLIC OF).

In this study, the synthesis of new spiropyrazoles, pyrazole and hydantoin hetercycles is reported by three compounent reactions of parabanic acids, hydrazine derivatives, and phenacyl bromides in the presence of triphenylphosphine as a nucleophile and triethylamine as a base in good to high yields (69-91%). Evaluation of the synthesized compounds revealed a good to excellent antioxidant activities (37.6-96. Read More

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Synergy of Solid-State NMR, Single-Crystal X-ray Diffraction, and Crystal Structure Prediction Methods: A Case Study of Teriflunomide (TFM).

Cryst Growth Des 2021 Jun 10;21(6):3328-3343. Epub 2021 May 10.

Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland.

In this work, for the first time, we present the X-ray diffraction crystal structure and spectral properties of a new, room-temperature polymorph of teriflunomide (TFM), CSD code 1969989. As revealed by DSC, the low-temperature TFM polymorph recently reported by Gunnam et al. undergoes a reversible thermal transition at -40 °C. Read More

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Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides.

Angew Chem Int Ed Engl 2021 Jul 14. Epub 2021 Jul 14.

Westlake University, School of Science, 18 Shilongshan Road, 310024, Hangzhou, CHINA.

Nucleophilic aromatic substitution (S N Ar) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile. However, this method is generally limited to electron-deficient arenes. We have now established a reliable method for accessing phenols, as well as phenyl alkyl ethers via catalytic S N Ar reactions. Read More

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Amino alcohol acrylonitriles as broad spectrum and tumour selective cytotoxic agents.

RSC Med Chem 2021 Jun 9;12(6):929-942. Epub 2021 Mar 9.

Experimental Therapeutics Group, Department of Medical Oncology, Calvary Mater Newcastle Hospital Edith Street Waratah NSW 2298 Australia.

We have identified specific dichlorophenylacrylonitriles as lead compounds in the development of novel anticancer compounds, notably, ()--(4-(2-cyano-2-(3,4-dichlorophenyl)vinyl)phenyl)acetamide () and ANI-7 (). Herein we specifically probe the SAR associated with the terminal aromatic ring and associated cytoxicity in a broad range of human cancer cell lines. Synthesis of three focused libraries revealed a poor tolerance for electron withdrawing and donating moieties (Library A). Read More

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LC-MS based metabolomic approach for the efficient identification and relative quantification of bioavailable cocoa phenolics in human urine.

Food Chem 2021 Jun 24;364:130198. Epub 2021 Jun 24.

Campus Ring 1, Jacobs University Bremen, 28759 Bremen, Germany. Electronic address:

This study was designed to investigate the rate and extent of urinary excretion of cocoa phenolic metabolites after human intake using metabolomics approach. In this context, a feeding trial was conducted where urine samples were collected at different time points over 48-h period. Several biomarkers were highlighted in LC-MS based chemometrics using principal component (PCA) and partial least squares discriminant analysis (PLS-DA), which revealed the presence of both epicatechin and gut microbial phenyl-γ-valerolactones (PVLs) conjugated analogues. Read More

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An Ortho-Tetraphenylene-Based «Geländer»-Architecture Consisting Exclusively of 52 sp2 Hybridized C-Atoms.

Chemistry 2021 Jul 13. Epub 2021 Jul 13.

University of Basel, Department of Chemistry, St.Johanns-Ring 19, 4056, Basel, SWITZERLAND.

A new type of «Geländer»-molecule based on a ortho -tetra-phenylene core is presented. The central para -quaterphenyl back-bone is wrapped by a 4,4'-di(( Z )-styryl)-1,1'-biphenyl banister, with its aryl rings covalently attached to all four phenyl rings of the backbone. The resulting helical chiral bicyclic architecture consist exclusively of sp 2 hybridized carbon atoms. Read More

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Evaluating the nature of the vertical excited states of fused-ring electron acceptors using TD-DFT and density-based charge transfer.

Phys Chem Chem Phys 2021 Jul;23(28):15282-15291

School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China.

Acceptor-donor-acceptor structured fused-ring electron acceptors (FREAs) are the most efficient electron acceptors used in organic solar cells. We use density functional theory (DFT), its time-dependent version (TD-DFT), and an intra-molecular charge transfer index to evaluate the nature of the excited states of FREAs. Typically, several efficient electronic transitions contribute to the absorption spectra of FREAs. Read More

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Electron attachment to tetrazoles: The influence of molecular structure on ring opening reactivity.

J Chem Phys 2021 Jun;154(21):214303

J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3, 182 23 Prague 8, Czech Republic.

The electron-induced reactivity of 5-(4-chlorophenyl)-1H-tetrazole and 5-chloro-1-phenyl-1H-tetrazole was studied using a trochoidal electron monochromator quadrupole mass spectrometer experimental setup. 5-(4-chlorophenyl)-1H-tetrazole underwent dissociative electron attachment to form Cl, [M-HCl], and [M-H]. 5-chloro-1-phenyl-1H-tetrazole underwent associative electron attachment to form the parent anion and dissociative electron attachment to form Cl, CNCl, [M-N-Cl], and [M-HCl]. Read More

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Substituted nitrogen-bridged diazocines.

Beilstein J Org Chem 2021 25;17:1503-1508. Epub 2021 Jun 25.

Otto Diels-Institute of Organic Chemistry, Christian Albrechts University Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany.

Novel nitrogen-bridged diazocines (triazocines) were synthesized that carry a formyl or an acetyl group at the CHNR-bridge and bromo- or iodo-substituents at the distant phenyl ring. The photophysical properties were investigated in acetonitrile and water. As compared to previous approaches the yields of the intramolecular azo cyclizations were increased (from ≈40 to 60%) using an oxidative approach starting from the corresponding aniline precursors. Read More

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Design, synthesis, and anticancer activity evaluation of curcumol derivatives.

J Asian Nat Prod Res 2021 Jul 8:1-13. Epub 2021 Jul 8.

College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China.

A new series of C-14 curcumol derivatives as potent anticancer agents were designed and synthesized by click reaction, whose structures were confirmed by H NMR,C NMR, and HRMS analysis. All the synthesized compounds were evaluated for antitumor activity against colorectal cancer cell lines SW620 and HCT116. Most of them exhibited higher inhibitory activity than curcumol. Read More

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Design, Synthesis, Anticancer Evaluation, and Molecular Docking Studies of Novel Benzoxazole Linked 1,3,4-Oxadiazoles.

Anticancer Agents Med Chem 2021 Jul 6. Epub 2021 Jul 6.

Department of Pharmacy, & Department of Chemistry, University College of Science, Osmania University, Hyderabad, Telangana-500 007, India.

Background: Cancer disease is making a serious concern globally. Global cancer occurrence is steadily increasing every year. There is always a persistent need to develop new anticancer drugs with reduced side effects or act synergistically with the existing chemotherapeutics. Read More

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Synthesis of benzoxazole-based vorinostat analogs and their antiproliferative activity.

Bioorg Chem 2021 Jun 28;114:105132. Epub 2021 Jun 28.

Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15771, Greece; Center of Excellence for Drug Design and Discovery, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15771, Greece. Electronic address:

Hydroxamic acid derivatives constitute an interesting novel class of antitumor agents. Three of them, including vorinostat, are approved drugs for the treatment of malignancies, while several others are currently under clinical trials. In this work, we present new vorinostat analogs containing the benzoxazole ring as the cap group and various linkers. Read More

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Formation and Cycloaddition Reactions of a Reactive Internally N-heterocyclic Carbene-stabilized Boraalkene.

Angew Chem Int Ed Engl 2021 Jul 4. Epub 2021 Jul 4.

Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster, Organisch-Chemisches Institut, GERMANY.

The synthesis of element-carbon double bonds is of great importance for the development and understanding of reactive π-bonded systems in chemistry. The seven-membered heterocyclic system 4b is readily made by internal C-H activation at a pendent isopropyl methyl group of the respective [(IPr)C6F5BH]+ borenium ion. Subsequent deprotonation with the IMes carbene gives the neutral cyclic boraalkene system 5b. Read More

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Discovery of memantyl urea derivatives as potent soluble epoxide hydrolase inhibitors against lipopolysaccharide-induced sepsis.

Eur J Med Chem 2021 Jun 29;223:113678. Epub 2021 Jun 29.

Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, Liaoning, 110016, China. Electronic address:

Sepsis, a systemic inflammatory response, caused by pathogenic factors including microorganisms, has high mortality and limited therapeutic approaches. Herein, a new soluble epoxide hydrolase (sEH) inhibitor series comprising a phenyl ring connected to a memantyl moiety via a urea or amide linkage has been designed. A preferential urea pharmacophore that improved the binding properties of the compounds was identified for those series via biochemical assay in vitro and in vivo studies. Read More

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N-(anilinoethyl)amide melatonergic ligands with improved water solubility and metabolic stability.

ChemMedChem 2021 Jul 2. Epub 2021 Jul 2.

Universita degli Studi di Urbino Carlo Bo, Dipartimento di Scienze Biomolecolari, ITALY.

The N-(anilinoethyl)amide derivative UCM765, is an MT 2 -selective partial agonist with hypnotic, analgesic and anxiolytic properties in rodents, but suffers from low water solubility and modest metabolic stability. To overcome these limitations, different strategies were investigated, including modification of metabolically liable sites, introduction of hydrophilic substituents and design of more basic derivatives. Thermodynamic solubility, microsomal stability and lipophilicity of new compounds were experimentally evaluated, together with their MT 1 and MT 2 binding affinities. Read More

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Substituent Effect in the Cation Radicals of Monosubstituted Benzenes.

Int J Mol Sci 2021 Jun 28;22(13). Epub 2021 Jun 28.

National Medicines Institute, 00-725 Warsaw, Poland.

In 30 monosubstituted benzene cation radicals, studied at the ωB97XD/aug-cc-pVTZ level, the phenyl rings usually adopt a compressed form, but a differently compressed form-equivalent to an elongated one-may coexist. The computational and literature ionization potentials are well correlated. The geometrical and magnetic aromaticity, estimated using HOMA and NICS indices, show the systems to be structurally aromatic but magnetically antiaromatic or only weakly aromatic. Read More

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Novel Triarylamine-Based Hole Transport Materials: Synthesis, Characterization and Computational Investigation.

Materials (Basel) 2021 Jun 7;14(11). Epub 2021 Jun 7.

Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia.

Three novel triarylamine-based electron-rich chromophores were synthesized and fully characterized. and were designed with electron-rich triphenylamine skeleton bearing two and four decyloxy groups namely, 3,4-bis(decyloxy)--diphenylaniline and -(3,4-bis(decyloxy)phenyl)-3,4-bis(decyloxy)--phenylaniline, respectively. The well-known electron-rich phenothiazine was introduced to diphenylamine moiety through a thiazole ring to form -bis(3,4-bis(decyloxy)phenyl)-5-(10-phenothiazin-2-yl)thiazol-2-amine (). Read More

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Investigation of kinetics of phenyl radicals with ethyl formate in the gas phase using cavity ring-down spectroscopy and theoretical methodologies.

Photochem Photobiol Sci 2021 Jul 1;20(7):859-873. Epub 2021 Jul 1.

Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India.

The gas-phase kinetics of phenyl radical (CH) with ethyl formate (HCOEt, EF) was investigated experimentally using ultrasensitive laser-based cavity ring-down spectroscopy (CRDS). Phenyl radicals were generated by photolyzing nitrosobenzene (CHNO) at 248 nm and thereby probed at 504.8 nm. Read More

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Validation of potential energy distribution by VEDA in vibrational assignment some of β-diketones; comparison of theoretical predictions and experimental vibration shifts upon deutration.

J Mol Graph Model 2021 Jun 24;107:107976. Epub 2021 Jun 24.

Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100, Copenhagen Ø, Denmark.

The harmonic vibrational frequencies of the cis-enol forms of some of β-diketones with different substitution in beta position, vis. H, CH3, and Ph ring, as the symmetric and asymmetric molecules, were calculated using density functional theory (DFT) at the B3LYP/6-311++G(d,p) level of theory. The results of DFT calculations were used to obtain the potential energy distribution (PED) by VEDA software. Read More

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Novel Cephalosporin Conjugates Display Potent and Selective Inhibition of Imipenemase-Type Metallo-β-Lactamases.

J Med Chem 2021 Jul 28;64(13):9141-9151. Epub 2021 Jun 28.

Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands.

In an attempt to exploit the hydrolytic mechanism by which β-lactamases degrade cephalosporins, we designed and synthesized a series of novel cephalosporin prodrugs aimed at delivering thiol-based inhibitors of metallo-β-lactamases (MBLs) in a spatiotemporally controlled fashion. While enzymatic hydrolysis of the β-lactam ring was observed, it was not accompanied by inhibitor release. Nonetheless, the cephalosporin prodrugs, especially thiomandelic acid conjugate (), demonstrated potent inhibition of IMP-type MBLs. Read More

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Mechanistic Studies of the Pd- and Pt-Catalyzed Selective Cyclization of Propargyl/Allenyl Complexes.

J Org Chem 2021 Jul 28;86(14):9670-9681. Epub 2021 Jun 28.

Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8675, Japan.

Following the discovery of an unusual transition-metal-catalyzed reaction, the elucidation of the underlying mechanism is essential to understand the characteristic reactivity of the metal. We previously reported a synthetic method for tricyclic indoles using Pt-catalyzed Friedel-Crafts-type C-H coupling. In this reaction, the Pt catalyst selectively formed a seven-membered ring, but the Pd catalyst only afforded a six-membered ring. Read More

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Structural improvement of new thiazolyl-isatin derivatives produces potent and selective trypanocidal and leishmanicidal compounds.

Chem Biol Interact 2021 Jun 24;345:109561. Epub 2021 Jun 24.

Departamento de Ciências Farmacêuticas, Centro de Ciências da Saúde, Universidade Federal de Pernambuco, 50740-535, Recife, PE, Brazil.

Neglected diseases are a group of transmissible diseases that occur mostly in countries in tropical climates. Among this group, Chagas disease and leishmaniasis stand out, considered threats to global health. Treatment for these diseases is limited. Read More

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Effects of substituent pattern on the intracellular target of antiproliferative benzo[b]thiophenyl chromone derivatives.

Eur J Med Chem 2021 May 25;222:113578. Epub 2021 May 25.

School of Pharmaceutical Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, 920-1192, Japan; Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27599-7568, United States. Electronic address:

A new biological scaffold was produced by replacing the 6π-electron phenyl ring-B of a natural flavone skeleton with a 10π-electron benzothiophene (BT). Since aromatic rings are important for ligand protein interactions, this expansion of the π-electron system of ring-B might change the bioactivity profile. One of the resulting novel natural product-inspired compounds, 2-(benzo[b]thiophen-3-yl)-5-hydroxy-7-isopropoxy-6-methoxyflavone (6), effectively arrested the cell cycle at the G2/M phase and displayed significant antiproliferative effects with IC values of 0. Read More

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