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1
Soni, Hetal I., and Navin B. Patel. "PYRIMIDINE INCORPORATED SCHIFF BASE OF ISONIAZID WITH THEIR SYNTHESIS, CHARACTERIZATION AND IN VITRO BIOLOGICAL EVALUATION." Asian Journal of Pharmaceutical and Clinical Research 10, no. 10 (September 1, 2017): 209. http://dx.doi.org/10.22159/ajpcr.2017.v10i10.19302.
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Objective: Versatile biological activities of nitrogen containing heterocycles in medicinal chemistry, mainly pyrimidine and pyridine ring based heterocyclic moieties are very important. Pharmaceutical important of pyrimidine and isoniazid moiety prompted us to synthesize isoniazid clubbed pyrimidine derivatives and evaluated for antimicrobial and antituberculosis activity.Method: 2-(2-(3-bromo benzylidene)-1-isonicotinoyl hydrazinyl)-N-(4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl) acetamide 2(A-J) have been synthesized by condensation reaction of 2-chloro-N-[4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl] acetamide and N’-[(E)- (3-bromophenyl) methylidene]pyridine-4-carbohydrazide. All newly synthesized compounds were screened for in vitro antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus pyogenes, antifungal against Candida albicans, Aspergillus niger, and Aspergillus clavatus, and antituberculosis activity against Mycobacterium tuberculosis H37RV.Results: Majority of the compounds exhibited good antibacterial, antifungal, and antituberculosis activity. All titled compounds were characterized by spectral analyses (infrared spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectroscopy).Conclusion: 2-(2-(3-bromo benzylidene)-1-isonicotinoyl hydrazinyl)-N-(4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl) acetamide 2(A-J) showed good antimicrobial activity and comparatively good antituberculosis activity. Hence, all the compounds of this series considered for future investigation mainly in area of antibacterial, antifungal study.
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Lyukshenko, Natalya I., Roman G. Nikitin, and Yury V. Morozhenko. "New technology to obtain 1-methyl-5-pnenyl-7-chloro- 1,3-dihydro-2H-[1,4]-benzodiazepine-2-one." Butlerov Communications 60, no. 10 (October 31, 2019): 24–31. http://dx.doi.org/10.37952/roi-jbc-01/19-60-10-24.
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At present, benzodiazepine derivatives being used widely, they continue to occupy a leading position among the drugs of the anxiolytic group. Most anxiolytics of the benzodiazepine structure are derivatives of 1,4-benzodiazepine. The basis of the chemical benzodiazepine structure consists of a benzene ring connected to a seven-membered heterocyclic ring containing two nitrogen atoms (diazepine) at positions 1 and 4. All the benzodiazepine derivatives used in the clinic also have a second benzene ring attached to carbon. The presence of a halogen or a nitro group is essential to display its activity. Diazepam (1-methyl-5-phenyl-7-chloro-1,3-dihydro-2H- [1,4] benzodiazepin-2-one) is in the list of necessary and important medicinal products. The urgent issue is the development of a new method to synthesize 1-methyl-5-phenyl-7-chloro-1,3-dihydro-2H-[1,4]-benzodiazepines-2-one that would allow producing the drug in the required quantities and for mass consumption. The search for possible effective ways of synthesizing 1-methyl-5-phenyl-7-chlorine-1,3-dihydro-2H-[1,4]-benzodiazepines-2-one for manufacturing application is of great scientific and practical interest. The purpose of our work is to search for a rational method to synthesize the target product, experimental study of the chemical processes to develop the most optimal methods to produce the product. The technology to produce 1-methyl-5-phenyl-7-chlor-1,3-dihydro-2H-[1,4]-benzodiazepine-2-one on an industrial scale was developed. The synthesis of 2-benzoyl-2',4-dichloro-N-methylacetanilide by condensation of 2-methylamine-5-chlorobenzophenone with chloracetyl chloride in carbon tetrachloride without further treatment of the reaction mass with water and sodium carbonate was developed. The highest yield of 1-methyl-5-phenyl-7-chlorine-1,3-dihydro-2H-[1,4]-benzodiazepines-2-one was shown to be obtained if the cyclization reaction is carried out in isopropyl alcohol. The reaction mixture composition in interaction of 2-benzoyl- 2',4 -dichloro-N-methylacetanilide with urotropin plays the defining role in the formation of the target product.
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Maaninen, Arto, René T. Boeré, Tristram Chivers, and Masood Parvez. "Preparation and X-Ray Structure of 4-N,N′-Bis(trimethylsilyl)- amino-3,5-diisopropylphenylselenium Trichloride." Zeitschrift für Naturforschung B 54, no. 9 (September 1, 1999): 1170–74. http://dx.doi.org/10.1515/znb-1999-0913.
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The reaction of SeCl4 or SeCl2 with N,N′-bis(trimethylsilyl)-2,6-diisopropylaniline occurs not at the nitrogen atom but by electrophilic aromatic substitution at C-4 of the phenyl ring to give [(CH3)3Si]2NC6H2 (iPr2)SeCl3 , which crystallizes as the chloro-bridged dimer in the triclinic system, space group P1̅, a - 10.2598(17), b = 13.665(3), c = 9.7838(10) Å, a = 90.056(13), ß = 102.439(11), γ = 70.922(14)°, V = 1262.3(4) Å3, Z= 1. The dimer contains an essentially planar Cl2Se(μ-Cl)2SeCl2 unit, with trans apical (Me3Si)2NC6H2(iPr)2 groups, resulting in approximately square pyramidal geometry at Se. The bridging Se-Cl distances are unequal at 2.587(2) and 2.749(2) Å.
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Regimbal, Gregg A., and Alex R. Martin. "The Influence of Growth Regulators and Nitrogen on Leafy Spurge (Euphorbia esula) Control with Picloram." Weed Science 33, no. 1 (January 1985): 109–13. http://dx.doi.org/10.1017/s0043174500084010.
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The addition of chlorflurenol (methyl 2-chloro-9-hydroxyfluorene-9-carboxylate) at 0.6 kg ai/ha or mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl] acetamide} at 0.3 kg ai/ha to picloram (4-amino-3,5,6-tricloropicolinic acid) at 0.3 kg ae/ha increased leafy spurge (Euphorbia esulaL. # EPHES) control compared to picloram alone. Application of 84 kg/ha nitrogen in the fall prior to a spring treatment of 0.3 kg/ha picloram decreased the original stand (75%) compared to no nitrogen (18%). In greenhouse experiments, chlorflurenol and mefluidide increased the amount of14C-picloram absorbed approximately twofold when applied in combination but not when applied independently. Based on14C-picloram absorbed, chlorflurenol and mefluidide each increased the amount of14C translocated to the root system, whether applied independently or in combination with picloram. An increase in root bud numbers was observed following an application of 0.6 kg/ha chlorflurenol or nitrogen.
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Valente, E. J., S. B. Martin, and L. D. Sullivan. "Pseudoacids. II. 2-Acylbenzoic Acid Derivatives." Acta Crystallographica Section B Structural Science 54, no. 3 (June 1, 1998): 264–76. http://dx.doi.org/10.1107/s0108768197012020.
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Structures of derivatives of cyclic o-acylbenzoic acids, including the chloride, endo- and exocyclic amides, esters and anhydrides, are examined. 3-Chloro-1(3H)-isobenzofuranone (1), orthorhombic, Pbca, a = 11.616 (5), b = 8.120 (3), c = 15.640 (9) Å; 3-methoxy-3-phenyl-1(3H)-isobenzofuranone (3), orthorhombic, P212121, a = 6.923 (2), b = 8.291 (4), c = 21.551 (8) Å; 3-hydroxy-3-phenyl-N-propyl-1(3H)-isoindolone (4), orthorhombic, P212121, a = 8.662 (4), b = 9.551 (7), c = 17.649 (14) Å; 3-(N-morpholino)-1(3H)-isobenzofuranone (5), triclinic, P1¯, a = 6.172 (4), b = 11.163 (7), c = 17.33 (2) Å, α = 105.91 (6), β = 99.85 (6), γ = 97.57 (5)°; 3-(2′-benzoylbenzoyloxy)-3-phenyl-1(3H)-isobenzofuranone (7), triclinic, P1¯, a = 9.694 (3), b = 10.505 (4), c = 11.163 (4) Å, α = 80.58 (3), β = 80.41 (3), γ = 76.49 (3)°; bis[1(3H)-isobenzofuranone-3-yl]ether (8), monoclinic, I2/a, a = 15.31 (2), b = 6.111 (12), c = 28.30 (5) Å, β = 101.61 (12)°. An open oxoacid tertiary amide is also described: N-morpholino 2′-benzoylbenzamide (6): monoclinic, P21/c, a = 6.844 (4), b = 15.696 (8), c = 14.154 (7) Å, β = 99.43 (4)°. Pseudoacid derivatives form planar isobenzofuran and isoindole rings, and the former aldehyde/ketone carbon–heteroatom endocyclic and exocyclic bond distances show bond length variations which correlate with the relative basicities of the attached groups. Structures of both endocyclic and exocyclic nitrogen pseudoamides are reported as well as examples of the normal–pseudoanhydride and the dipseudoanhydride.
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Farah Smaysem and Ahmed Salim. "Synthesis and Characterization of Some Heterocyclic Compounds and Evaluation of Antibacterial Activity." International Journal of Research in Pharmaceutical Sciences 11, SPL4 (December 21, 2020): 2068–78. http://dx.doi.org/10.26452/ijrps.v11ispl4.4421.
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In this study, heterocyclic compounds with two nitrogen atoms are prepared by reaction of 2-aminobenzimidazole with formic acid to get amide derivatives (A), reacts with phenylhydrazine to get phenyl hydrazone derivatives (B), reacts with ethyl chloroacetate to obtain ethyl acetate derivatives (C). The derivative (D) obtains on heating in a basic medium. The (B) reacts with 2-chloroacetyl chloride to give derivatives (E). A number of Schiff bases are prepared (F, I) from reacting 2-aminobenzimidazole with benzaldehyde derivatives. The(F) reacts with propargyl bromide to give propargyl bromide derivatives (G). The cyclization with 4-nitrophenyl azide leads to obtain triazole compound (H). The compound (I) reacts with ethyl chloroacetate to give ethyl acetate derivatives (J), reacts with hydrazine to give N-amide hydrazine derivatives (K). The cyclization give rises to 1,3,4-oxadiazole derivatives (L). The compound (I) reacts with sodium azide to obtain tetrazole derivatives (M). Synthesizing of Triazine, Oxadiazole, Triazole, Tetrazole via cyclization of the Schiff base derivatives with ethyl chloroacetate and chloro acetyl chloride, benzoic acid, 4-nitrophenyl azide, sodium azide and phenyl azide are possible respectively. The FT-IR, 13C-NMR and 1H-NMR spectral data give good evidence for the formation of the compounds. Some prepared compounds exhibit antibacterial properties.
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Carroll, M. J., P. H. Dernoeden, and J. M. Krouse. "Zoysiagrass Establishment from Sprigs following Application of Herbicides, Nitrogen, and a Biostimulator." HortScience 31, no. 6 (October 1996): 972–75. http://dx.doi.org/10.21273/hortsci.31.6.972.
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Sprigs of `Meyer' zoysiagrass (Zoysia japonica Steud.) were treated with urea nitrogen, a biostimulator, and one of three preemergence herbicides or one of two postemergence herbicides to hasten establishment in two field studies. Monthly application of N at 48 kg·ha–1 during the growing season had no influence on sprig establishment the first year, but slightly increased (+5%) zoysiagrass cover the second year. Presoaking sprigs in a solution containing (mg·L–1) 173 auxin and 81 cytokinin, and iron at 1.25 g·L–1 before broadcasting of sprigs, and biweekly sprays (g·ha–1) of 53 auxin and 24 cytokinin, and iron at 0.2 g·L–1 or (g·ha–1) 68 auxin and 36 cytokinin, and iron at 1.45 g·L–1 after broadcasting sprigs had no effect on zoysiagrass cover or rooting. Preemergence and postemergence herbicide use generally enhanced zoysiagrass cover by reducing smooth crabgrass competition [Digitaria ischaemum (Schreb. ex Schweig) Schreb. ex Muhl]. Oxadiazon enhanced zoysiagrass coverage more than dithiopyr, pendimethalin, quinclorac, or fenoxaprop. Oxadiazon and dithiopyr provided similar levels of crabgrass control, but dithiopyr reduced `Meyer' zoysiagrass midsummer root growth. Chemical names used: 3,5,-pyridinedicarbothioic acid, 2-[difluromethyl]-4-[2-methyl-propyl]-6-(trifluoromethyl)-S,S-dimethyl ester (dithiopyr); [±]-ethyl 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy] propanoate (fenoxaprop); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); 3,7-dichloro-8-quin-olinecarboxylic acid (quinclorac).
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Mohabey, Hemlata. "IR Spectra, Magnetic and Thermal Studies of Copper (II) Complex of N-Hydroxy-N-(4-Chloro) Phenyl N’(4-Fluoro) Phenyl Benzamidine Hydrochloride." Material Science Research India 11, no. 1 (August 25, 2014): 63–65. http://dx.doi.org/10.13005/msri/110108.
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Copper (II) reacts with HCPFPBH and forms buff coloured precipitate insoluble in many organic solvents like absolute alcohol, ether, benzene, chloroform etc. The Solid complex has molecular formula (C19H13N2OFCl)2Cu which melts at 2020C with decomposition. The infrared spectra of the complex was recorded in the range 4000-450cm-1. The ligand molecule consists of a weak band at 2550 cm-1. This confirms the presence of azomethine nitrogen in the ligand. This band is absent in the IR Spectrum of the complex confirming the involvement of this group in complexation . The strong band of the ligand at 1640 cm-1 is due to C = NH+ group which shifts to lower frequency by 60 cm-1. This confirms the formation of C = N -----Cu bond. The N – O stretching mode shifts to higher frequency from 930 cm-1 to 960 cm-1 this confirms the formation of N – O – Cu bond by replacement of N – O – H proton by Copper.Cu – N band appears at 460 cm-1 which supports the formation of Cu – N bond. The positive value of volume susceptibility confirms that the complex is paramagnetic. TGA studies suggest that complex is thermally stable upto 2020C and melts with decomposition. At this temperature water molecules are absent which is also suggested by IR spectra of the complex. These studies support the use of N-Hydroxy-N-(4-Chloro) phenylN’-(4-Fluoro) phenyl benzamidine hydrochloride for gravimetric determination of Copper (II) in ores and alloys.
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Taj, Muhammad Babar, Muneera D. F. Alkahtani, Uzma Ali, Ahmad Raheel, Walla Alelwani, Afnan M. Alnajeebi, Nouf Abubakr Babteen, Sadia Noor, and Heba Alshater. "New Heteroleptic 3D Metal Complexes: Synthesis, Antimicrobial and Solubilization Parameters." Molecules 25, no. 18 (September 16, 2020): 4252. http://dx.doi.org/10.3390/molecules25184252.
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The microbial resistance to current antibiotics is increasing day by day, which in turn accelerating the development of new effective drugs. Several studies have proved the high antimicrobial potential of the interaction of several organic ligands with a variety of metal ions. In the present study, a conventional method has been adopted in the synthesis of twelve new heteroleptic complexes of cobalt (II), nickel (II), copper (II) and zinc (II) using three aldimines, namely, (HL1 ((E)-2-((4-chloro-2-hydroxybenzylidene)amino)-3,4-dimethyl-5-phenylcyclopent-2-en-1-one), HL2 ((Z)-3-((4-chlorobenzylidene)amino)-4-hydroxy-5-nitrobenzenesulfonic acid) HL3 (2,2′-((1,2-phenylenebis(azaneylylidene))bis(methaneylylidene))diphenol)) as primary ligands, while phenyl glycine was the secondary ligand. The synthesized compounds were characterized by UV-vis, IR and multinuclear (1H and 13C) NMR spectroscopy, elemental analysis, and electrical conductance. The IR study revealed the coordination of the aldimine derivatives with the -OH and N atom of imine moiety. In contrary to this, the phenyl glycine coordinated to the metal ions via oxygen of carboxylate and nitrogen of the amino group. The spectroscopic analysis unveiled the tetrahedral geometry of the synthesized metal (II) complexes, except for ligand HL3 which exhibited octahedral geometry. The synthesized compounds generally showed antibacterial activity for all microbes, except Ni (II) complexes lacking sensitivity. Furthermore, to access the bioavailability, the synthesized complexes were screened for their solubilization in the micellar media of sodium lauryl sulphate. The metal complex–surfactant interaction was revealed by UV-vis spectroscopy and electrical conductivity measurements.
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Gong, Nian, Xin-Yan Li, Qi Xiao, and Yong-Xiang Wang. "Identification of a Novel Spinal Dorsal Horn Astroglial d-Amino Acid Oxidase–Hydrogen Peroxide Pathway Involved in Morphine Antinociceptive Tolerance." Anesthesiology 120, no. 4 (April 1, 2014): 962–75. http://dx.doi.org/10.1097/aln.0b013e3182a66d2a.
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Abstract Background: d-Amino acid oxidase (DAAO) is a flavin adenine dinucleotide-dependent peroxisomal flavoenzyme which is almost exclusively expressed within astrocytes in the spinal cord. DAAO catalyzes oxidation of d-amino acids to hydrogen peroxide, which is a stable and less active reactive oxygen species, and may represent a final form of reactive oxygen species. This study tested the hypothesis that the spinal astroglial DAAO–hydrogen peroxide pathway plays an important role in the development of morphine antinociceptive tolerance. Methods: Rat and mouse formalin, hot-plate, and tail-flick tests were used, and spinal DAAO expression and hydrogen peroxide level were measured. Sample size of animals was six in each study group. Results: Subcutaneous and intrathecal DAAO inhibitors, including 5-chloro-benzo[d]isoxazol-3-ol, AS057278, and sodium benzoate, completely prevented and reversed morphine antinociceptive tolerance in the formalin, hot-plate, and tail-immersion tests, with a positive correlation to their DAAO inhibitory activities. Intrathecal gene silencers, small interfering RNA/DAAO and small hairpin RNA/DAAO, almost completely prevented morphine tolerance. Intrathecal 5-chloro-benzo[d]isoxazol-3-ol and small interfering RNA/DAAO completely prevented increased spinal hydrogen peroxide levels after chronic morphine treatment. Intrathecal nonselective hydrogen peroxide scavenger phenyl-tert-N-butyl nitrone and the specific hydrogen peroxide catalyst catalase also abolished established morphine tolerance. Spinal dorsal horn astrocytes specifically expressed DAAO was significantly up-regulated, accompanying astrocyte hypertrophy after chronic morphine treatment. Conclusions: For the first time, the authors’ result identify a novel spinal astroglial DAAO–hydrogen peroxide pathway that is critically involved in the initiation and maintenance of morphine antinociceptive tolerance, and suggest that this pathway is of potential utility for the management of morphine tolerance and chronic pain.
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Abbas, Hayat Hamza, Majeed Yacoob Al-Luaibi, and Mohammed Jassem Al-Assadi. "New Heterocyclic Organo-Chalcogenide Compounds: Synthesis, Physicochemical Characterization, and Evaluation of Anticancer Activity against Breast Cancer Cells." Indonesian Journal of Chemistry 23, no. 2 (February 6, 2023): 309. http://dx.doi.org/10.22146/ijc.75582.
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This work aimed to synthesize, characterize and evaluate the thermal stability of new sulfur and selenium organochalcogenide derivatives and to test the cytotoxic activity against breast adenocarcinoma cell line (MCF-7) through conducting MTT assay and AO/EB dual staining-technique. Two series of ten organo-chalcogen compounds: 4-(substituted)phenylthiomorpholine-3,5-dione and 4-(substituted)phenylselenomorpholine-3,5-dione were prepared by the reaction of Na2S·3H2O and NaHSe with N-(substituted)phenyl-2-chloro-N-(2-chloroacetyl)acetamide, respectively, under nitrogen atmosphere to give the corresponding cyclic chalcogenide ligands. All new compounds were characterized by melting point, FTIR, elemental analysis, UV-Visible, 1H-NMR and 13C-NMR. Meanwhile, TG/DTA analysis of some of these ligands was conducted to evaluate the thermal stability, kinetic, and characteristic thermodynamic parameters. Absorption spectroscopy was used to investigate these compounds with human DNA. The experimental results investigated a hypochromic effect via intercalation binding mode. The role of the prepared ligands in breast cell lines has been investigated by conducting MTT assay via spectroscopic techniques on HBL100 and MCF-7, normal and cancer breast cell lines, respectively. Cell death was seen after AO/EB dye staining method employing the fluorescence microscopy technique. The results revealed that these compounds possess cytotoxic activity on the MCF-7 and HBL-100 cell lines at a fixed concentration.
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Malik, Suman, Suparna Ghosh, Bharti Jain, Archana Singh, and Mamta Bhattacharya. "Synthesis, Characterization, and Biological Evaluation of Some 3d-Metal Complexes of Schiff Base Derived from Xipamide Drug." International Journal of Inorganic Chemistry 2013 (February 18, 2013): 1–6. http://dx.doi.org/10.1155/2013/549805.
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The present paper deals with the synthesis and characterization of metal complexes of Schiff base derived from xipamide, a diuretic drug. The bidentate ligand is derived from the inserted condensation of 5-aminosulfonyl-4-chloro-N-2,6-dimethyl phenyl-2-hydroxybenzamide (Xipamide) with salicylaldehyde in a 1 : 1 molar ratio. Using this bidentate ligand, complexes of Hg(II), Zn(II), and VO(IV) with general formula ML2 have been synthesized. The synthesized complexes were characterized by several techniques using molar conductance, elemental analysis, magnetic susceptibility, FT-IR spectroscopy, electronic spectra, mass spectra, and particle size analysis. The elemental analysis data suggest the stoichiometry to be 1 : 2 [M : L]. All the complexes are nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through deprotonated phenolic oxygen and azomethine nitrogen atoms. Spectral studies suggest tetrahedral geometry for Hg(II), Zn(II) complexes, and square pyramidal geometry for VO(IV) complex. The pure drug, synthesized ligand, and metal complexes were screened for their antifungal activities against Aspergillus niger and Aspergillus flavus. The ligand and its Hg(II) and VO(IV) complexes were screened for their diuretic activity too.
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Chamorro, Beatriz, Sara Izquierdo-Bermejo, Julia Serrano, Dimitra Hadjipavlou-Litina, Mourad Chioua, Francisco López-Muñoz, José Marco-Contelles, Ricardo Martínez-Murillo, and María Jesús Oset-Gasque. "Neuroprotective and antioxidant properties of new quinolylnitrones in in vitro and in vivo cerebral ischemia models." Scientific Reports 13, no. 1 (February 17, 2023). http://dx.doi.org/10.1038/s41598-023-29929-7.
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AbstractCerebral ischemia is a condition affecting an increasing number of people worldwide, and the main cause of disability. Current research focuses on the search for neuroprotective drugs for its treatment, based on the molecular targets involved in the ischemic cascade. Nitrones are potent antioxidant molecules that can reduce oxidative stress. Here we report the neuroprotective properties and the antioxidant power of the six new quinolylnitrones (QNs) 1–6 for their potential application in stroke therapy. QNs 1–4 are 2-chloro-8-hydroxy-substituted QNs bearing N-t-butyl or N-benzyl substituents at the nitrone motif located at C3, whereas QN5 and QN6 are 8-hydroxy QNs bearing N-t-butyl or N-benzyl substituents at the nitrone motif located at C2, respectively. In vitro neuroprotection studies using QNs 1–6 in an oxygen-glucose-deprivation model of cerebral ischemia, in human neuroblastoma cell cultures, indicate that all QNs have promising neuroprotective, anti-necrotic, anti-apoptotic, and anti-oxidant properties against experimental ischemia–reperfusion in neuronal cultures. QN6 stands out as the most balanced nitrone out of all tested QNs, as it strongly prevents decreased neuronal metabolic activity (EC50 = 3.97 ± 0.78 μM), as well as necrotic (EC50 = 3.79 ± 0.83 μM) and apoptotic cell death (EC50 = 3.99 ± 0.21 μM). QN6 showed high capacity to decrease superoxide production (EC50 = 3.94 ± 0.76 μM), similar to its parent molecule α-phenyl-tert-butyl nitrone (PBN) and the well-known anti-oxidant molecule N-acetyl-l-cysteine (NAC). Thus, QN6 demonstrated the highest antioxidant power out of the other tested QNs. Finally, in vivo treatment with QN6 in an experimental permanent stroke model elicited a significant reduction (75.21 ± 5.31%) of the volume size of brain lesion. Overall, QN6 is a potential agent for the therapy of cerebral ischemia that should be further investigated.
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Krevlin, Zoe A., Isabella C. Bote, Maria Christina F. Crespo, Christie C. Lam, Colin D. McMillen, and Max M. Majireck. "Synthesis and crystal structure of a bench-stable pyridinium ketene hemiaminal: 1-(1-ethoxyethenyl)-2-[methyl(phenyl)amino]pyridin-1-ium trifluoromethanesulfonate." Acta Crystallographica Section E Crystallographic Communications 79, no. 8 (July 7, 2023). http://dx.doi.org/10.1107/s2056989023005741.
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The novel bench-stable N-quaternized ketene N,O-acetal, C16H19N2O+·CF3O3S−, was synthesized and its structure determined. The title compound is a rare example of a pyridinium ketene hemiaminal for which a crystal structure has been determined, joining the 2-chloro-1-(1-ethyoxyethenyl)pyridin-1-ium trifluoromethanesulfonate salt from which it was synthesized. The cationic species of the title compound can be defined by three individually planar fragments assembling into a non-coplanar cation. The phenyl substituent extending from the amino nitrogen atom and the ethyoxyvinyl substituent extending from the pyridine N atom are oriented on the same side of the molecule and maintain the closest coplanar relationship of the three fragments. Supramolecular interactions are dominated by C—H...O interactions from the cation to the SO3 side of the trifluoromethanesulfonate anion, forming a two-dimensional substructure.
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Hata, Takeshi, Yuta Tatsumi, Yuuki Kanai, Naoto Takahashi, Masayuki Shigeta, and Hirokazu Urabe. "Preparation of Hetero‐π‐conjugated Compounds by Double Nucleophilic Addition to Haloalkynes and C‐H Cyclization." Advanced Synthesis & Catalysis, March 5, 2024. http://dx.doi.org/10.1002/adsc.202301510.
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When a mixture containing 1‐halo‐1‐alkyne, a dinucleophilic agent, and a base (Cs<sub>2</sub>CO<sub>3</sub> or K<sub>3</sub>PO<sub>4</sub>) was heated in DMF, regio‐ and stereo‐selective nucleophilic addition of the dinucleophilic agent to the acetylenes occurred. This reaction yielded (<i>Z</i>,<i>Z</i>)‐bis(haloalkene), which subsequently underwent Pd‐catalyzed cyclization through C–H bond activation, resulting in the formation of two‐oxygen‐ or ‐nitrogen‐containing hetero‐π‐conjugated compounds. <i>N</i>‐(5‐Hydroxynaphthalen‐1‐yl)methanesulfonamide was treated with 2‐phenyl‐1‐chloroethyne followed by 1‐chloro‐1‐hexadecyne. After these reactions, Pd‐catalyzed double C–H cyclization was employed to produce 1<i>H</i>‐2‐phenyl‐7‐tetradecylbenzofuro[7,6‐<i>g</i>]indole. Notably, this compound transformed into a fan‐shaped structure at 86 °C and transitioned into a smectic A phase characterized by a layered structure.
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Ben Ahmed, Sophia, Gema Pérez de Bustos, João Pina, Tomás Torres, and M. Salomé Rodríguez‐Morgade. "Tuning Fluorescence and Singlet Oxygen Quantum Yields of Subporphyrazines by Axial Functionalization." ChemPlusChem, February 6, 2024. http://dx.doi.org/10.1002/cplu.202300779.
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AbstractThe axial functionalization of Subporphyrazines (SubPzs) with unreported alkoxy groups, carboxy and carboperoxy rests, as well as sulfanyl, aryl and amino groups, forming B−O, B−S, B−C, and B−N bonds, respectively, has been investigated. The studied oxygen nucleophiles include aromatic and sterically demanding aliphatic alcohols, along with carboxylic acids and peracids. In general, direct substitution of the chloro‐SubPz by oxygen nucleophiles of diverse nature proceeds smoothly, with yields of the isolated alkoxy and carboxy‐substituted SubPzs ranging from 49 to 100 %. Conversely, direct substitution with sulphur, carbon and nitrogen nucleophiles do not afford the corresponding substituted SubPzs. In these cases, a stepwise procedure involving an axial triflate‐SubPz intermediate was employed, affording only the phenyl‐SubPz in 8 % yield. The major compound under these conditions was the unreported SubPz μ‐oxo dimer, presumably arising from substitution of the triflate‐SubPz by the in situ generated hydroxy‐SubPz. This result indicates a quite low reactivity of the TfO‐SubPz intermediate with carbon, sulphur and nitrogen nucleophiles. All SubPzs prepared in this work exhibited fluorescence at 510–515 nm with quantum yields ranging from 0.1 to 0.24. Additionally, all SubPzs generated singlet oxygen, with ΦΔ values ranging from 0.15 to 0.57, which show no apparent correlation with the axial substituents.