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Short-Lived Positron Emitting Radionuclides
Published in Frank Helus, Lelio G. Colombetti, Radionuclides Production, 2019
The preparation of methyl labeled 11C-l-methionine was achieved by the reaction of S-benzylhomocysteine96 or l-homocysteine.202,206 The methionine prepared was used as intermediate in 11C-labeling of methionine-containing polypeptides.207 From 11CH3I and an isocyanide Kloster prepared DL-3-11C-alanine.208 Partially resolved l-alanine labeled in the 3-position was obtained by an asymmetric synthesis.196
Physiological Implications of Ferrihemoglobinemia
Published in Manfred Kiese, Methemoglobinemia: A Comprehensive Treatise, 2019
NMR studies with normal human adult hemoglobin, hemoglobin A, have shown that α- and β-hemes are functionally nonequivalent. Different from its behavior towards isolated α- and β-chains,651–653 oxygen binds to the α-hemes in preference to the β-hemes,654,655 and n-butyl isocyanide binds to the β-hemes in preference to the α-hemes.656 Differences in binding to α- and β-chains in the hemoglobin molecule have also been observed with carbon monoxide.657 Isolated α- and β-chains show different oxidation-reduction potentials, Em at pH 7 being + 0.113 V for β-chains and + 0.052 V for α-chains.658 Correspondingly, differences between oxidation-reduction potentials have also been found with the hemoglobin tetramer, β-chains showing higher electron affinity than α-chains. They are more rapidly reduced by dithionite and oxidized by ferricyanide when the iron is in the ferric and ferrous state, respectively.659 In a solution, or a red cell, with partially oxidized hemoglobin, in equilibrium the ferrihemes are not randomly distributed, but α-chains contain a higher proportion of them than β-chains.
Linkers in fragment-based drug design: an overview of the literature
Published in Expert Opinion on Drug Discovery, 2023
Dylan Grenier, Solène Audebert, Jordane Preto, Jean-François Guichou, Isabelle Krimm
As proposed by Mancini et al. [76], multicomponent reactions (MCRs) represent another KTGS method where ‘one-pot reactions, in which more than two starting materials are incorporated to form a new adduct comprising most of the structural motifs of the starting building block.’ Gladysz et al. [77] performed a Groebke–Blackburn-Bienaymé reaction templated by Urokinase plasminogen activator (uPA). An isocyanide moiety reacted with three aldehydes and two amines in the presence of uPA to generate an imidazopyridine amine inhibitor (IC50 = 0.184 µM). Recently, Mancini et al. [76] also used an example of a multicomponent reaction (Ugi 4-Component Reaction : 4-CR) using endothiapepsin as a protein model. The fragments contained either carboxylic acid, amine, aldehyde, or isocyanide moieties. The best compound showed an improved activity (IC50 = 1.3 µM) compared to the original inhibitor (IC50 = 12.8 µM).
Preparation of chitosan-coated liposomes as a novel carrier system for the antiviral drug Triazavirin
Published in Pharmaceutical Development and Technology, 2018
Ksenia V. Kozhikhova, Maria N. Ivantsova, Maria I. Tokareva, Iliya D. Shulepov, Andrey V. Tretiyakov, Lev V. Shaidarov, Vladimir L. Rusinov, Maxim A. Mironov
Epikuron 200 composed of phosphatidylcholine with molecular weight 908.8 g/mol (min 95%) was obtained from Cargill Inc. (Minnetonka, MN). Triazavirin (purity 99%)27 as a registered pharmaceutical substance in sodium salt form was produced by Zavod Medsintez LLC (Novouralsk, Russia). Cetylpyridinium chloride, phosphoric acid, Coomassie Brilliant Blue G-250, mucin (extracted from porcine stomach, type III), trimethylamine, lauric acid and pelargonic acid were purchased from Sigma-Aldrich, Inc. (St. Louis, MO). Tocopheryl acetate was purchased from Galaxy Surfactants Ltd. (Navi Mumbai, India). Palmitoyl chloride and stearoyl chloride were obtained from BASF (Ludwigshafen, Germany). Water-soluble 2-methoxyethyl isocyanide was purchased from TOSLab (Ekaterinburg, Russia). Chitosan with a relative molecular mass of 1.9 × 105 Da and a 5% degree of acetylation was purchased from Heppe Medical Chitosan GmbH (Halle, Germany). Chitosan derivatives were synthesized by the method based on the Ugi four-component condensation28. Toluene, hexane, heptane, acetonitrile, ethanol and acetic acid were obtained from Acros Organic (Geel, Belgium). Sodium hydroxide, hydrochloric acid, phosphate buffer solution (pH = 6.86) and chloroform were of analytical grade from Ekros (Saint Petersburg, Russia). Methyl palmitate was obtained from Univerxim (Chelyabinsk, Russia).
Donepezil + chromone + melatonin hybrids as promising agents for Alzheimer’s disease therapy
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Irene Pachón-Angona, Bernard Refouvelet, Rudolf Andrýs, Helène Martin, Vincent Luzet, Isabel Iriepa, Ignacio Moraleda, Daniel Diez-Iriepa, María-Jesús Oset-Gasque, José Marco-Contelles, Kamil Musilek, Lhassane Ismaili
A solution of the corresponding N-benzylpiperidines 8–11 (1.0 mmol) and paraformaldehyde (13) (1.0 mmol) in MeOH/CH2Cl2 (7 ml, 3:1, v/v) was stirred for 1 h at room temperature (rt). Chromone-2-carboxylic acid (12) (1.0 mmol) and the appropriate isocyanide 4–7 (1.0 mmol) were then added. The reaction was stirred 24 h at rt, and when complete (tlc control), the crude product was isolated and purified by flash column chromatography to afford the corresponding hybrids 14a–p (see Supplementary Material).