- Novel pyridine-2,4,6-tricarbohydrazide derivatives: Design, synthesis, characterization and in vitro biological evaluation as α- And β-glucosidase inhibitors
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A range of novel pyridine 2,4,6-tricarbohydrazide derivatives (4a-4h) were synthesized and its biological inhibition towards α- and β-glucosidases was studied. Most of the compounds demonstrate to be active against α-glucosidase, and quite inactive/comple
- Riaz, Sadaf,Khan, Islam Ullah,Yar, Muhammad,Ashraf, Muhammad,Rehman, Tanzeel Ur,Shaukat, Ayesha,Jamal, Syed Babar,Duarte, Vera C.M.,Alves, Maria J.
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- Factors Influencing the Course of the Macrocyclization of α,ω-Diamines with Esters of α,ω-Dicarboxylic Acids
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The efficient synthesis of eight new macrocyclic amides (lactams) via reaction of diesters with diamines under normal dilution conditions is described. The role of intermolecular H-bond formation and steric hindrance is discussed based on 1H- a
- Gryko, Dorota,Gryko, Daniel T.,Sierzputowska-Gracz, Hanna,Piatek, Piotr,Jurczak, Janusz
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- Investigation of the preparation and reactivity of metal-organic frameworks of cerium and pyridine-2,4,6-tricarboxylate
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The synthesis of three coordination polymers of cerium(iii) and the ligand pyridine-2,4,6-tricarboxylate (PTC) is reported. Two of the materials crystallise under hydrothermal conditions at 180 °C, with [Ce(PTC)(H2O)2]·1.5H2O, (1), being formed on extended periods of reaction time, 3 days or longer, and Ce(PTC)(H2O)3, (2), crystallising after 1 day. Both phases contain Ce(iii) but are prepared using the Ce(iv) salt Ce(SO4)2·4H2O as reagent. Under solvothermal conditions (mixed water-N,N-dimethylformamide (DMF)), the phase [Ce(PTC)(H2O)(DMF)]·H2O (3) is crystallised. The structures of the three materials are resolved by single crystal X-ray diffraction, with the phase purity of the samples determined by powder X-ray diffraction and thermogravimetric analysis. (1) is constructed from helical chains cross-linked by the PTC linkers to give a three-dimensional structure that contains clusters of water molecules in channels that are hydrogen-bonded to each other and to additional waters that are coordinated to cerium. (2) also contains nine-coordinate cerium but these are linked to give a dense framework, in which water is directly coordinated to cerium. (3) contains corner-shared nine-coordinate cerium centres, linked to give a framework in which Ce-coordinated DMF fills space. Upon heating the material (1) in air all water is irreversibly lost to give a poorly crystalline anhydrous phase Ce(PTC), as deduced from X-ray thermodiffractometry and thermogravimetric analysis. The material (1), however, is hydrothermally stable, and is also stable under oxidising conditions, where immersion in 30% H2O2gives no loss in crystallinity. Oxidation of around 50% of surface Ce to the +4 oxidation state is thus possible, as evidenced by X-ray photoelectron spectroscopy, which is accompanied by a colour change from yellow to orange. Photocatalytic activity of (1) is screened and the material shows effective degradation of methyl orange.
- Clarkson, Guy J.,Fonseca de Lima, Juliana,Franklin, Sian A.,Menezes, Bruno A. T.,Moreno, Fernanda V. S.,Serra, Osvaldo A.,Waddington, Matthew C.,Walker, Marc,Walton, Richard I.,da Silva Barbosa, Jader
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p. 145 - 155
(2021/12/27)
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- Synthetic Approaches to the Bifunctional Chelators for Radio nuclides Based on Pyridine-Containing Azacrown Compounds
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Synthetic ways to introduce functional groups (CO 2 Me, CO 2 H, OCH 2 CO 2 H, OCH 2 C≡CH, CH 2 OH, CH 2 Cl, CH 2 N 3) into the pyridine ring of pyridine-containing azacrown compounds are described. These groups were introduced at position-4 of the pyridine ring, while keeping the macrocyclic carboxylate groups available for metal chelation. The derivatives were obtained by macrocyclization reaction of 4-substituted, trimethyl pyridine-2,4,6-tricarboxylate or by modification of methyl ester group in pyridine fragment of macrocycles. Obtained derivatives can be applied for preparing radiotherapeutic agents by conjugation to different vector biomolecules for targeted drug delivery to cancer cells without damaging healthy tissue.
- Fedorova, Olga A.,Shchukina, Anna A.,Zubenko, Anastasia D.
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p. 1087 - 1095
(2020/04/01)
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- SYNTHESIS OF UBIQUINONE AND MENAQUINONE ANALOGUES BY OXIDATIVE DEMETHYLATION OF ALKENYLHYDROQUINONE ETHERS WITH ARGENTIC OXIDE OR CERIC AMMONIUM NITRATE IN THE PRESENCE OF 2,4,6-PYRIDINE-TRICARBOXYLIC ACID
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It was found that alkenylhydroquinone ethers demethylated with argentic oxide or ceric ammonium nitrate in the presence of 2,4,6-pyridinetricarboxylic acid as a catalyst and afforded ubiquinone-2, menaquinone-2 and their analogs in yields of 53 to 89 percent.The new approach to the synthesis of starting alkenylhydroquinone ethers as well as 2,4,6-pyridinetricarboxylic acid and its derivatives has been reported.
- Syper, L.,Kloc, K.,Mlochowski, J.
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p. 123 - 129
(2007/10/02)
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