10380-08-2Relevant academic research and scientific papers
Small molecule inhibition of SAMHD1 dNTPase by tetramer destabilization
Seamon, Kyle J.,Hansen, Erik C.,Kadina, Anastasia P.,Kashemirov, Boris A.,McKenna, Charles E.,Bumpus, Namandjé N.,Stivers, James T.
, p. 9822 - 9825 (2014)
SAMHD1 is a GTP-activated nonspecific dNTP triphosphohydrolase that depletes dNTP pools in resting CD4+ T cells and macrophages and effectively restricts infection by HIV-1. We have designed a nonsubstrate dUTP analogue with a methylene bridge connecting the α phosphate and 5′ carbon that potently inhibits SAMHD1. Although pppCH2dU shows apparent competitive inhibition, it acts by a surprising allosteric mechanism that destabilizes active enzyme tetramer.
Effect of the vanadium(v) concentration on the spectroscopic properties of nanosized europium-doped yttrium phosphates
Batista, Jonathan Carvalhaes,De Sousa Filho, Paulo Cesar,Serra, Osvaldo Antonio
, p. 6310 - 6318 (2012)
Nanosized rare earth phosphovanadate phosphors (Y(P,V)O4:Eu 3+) have been prepared by applying the organic-inorganic polymeric precursors methodology. Luminescent powders with tetragonal structure and different vanadate concentrations (0%, 1%, 5%, 10%, 20%, 50%, and 100%, with regard to the phosphate content) were then obtained for evaluation of their structural and spectroscopic properties. The solids were characterized by scanning electron microscopy, X-ray diffractometry, vibrational spectroscopy (Raman and infrared), and electronic spectroscopy (emission, excitation, luminescence lifetimes, chromaticity, quantum efficiencies, and Judd-Ofelt intensity parameters). The solids exhibited very intense 5D 0 → 7FJ Eu3+ transitions, and it was possible to control the luminescent characteristics, such as excitation maximum, lifetime and emission colour, through the vanadium(v) concentration. The observed luminescent properties correlated to the characteristics of the chemical environments around the Eu3+ ions with respect to the composition of the phosphovanadates. The Eu3+ luminescence spectroscopy results indicated that the presence of larger vanadium(v) amounts in the phosphate host lattice led to more covalent and polarizable chemical environments. So, besides allowing for control of the luminescent properties of the solids, the variation in the vanadate concentration in the obtained YPO 4:Eu3+ phosphors enabled the establishment of a strict correlation between the observable spectroscopic features and the chemical characteristics of the powders.
Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
supporting information, p. 5022 - 5037 (2021/05/04)
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
One-step Conversion of Amides and Esters to Acid Chlorides with PCl3
Li, Fangshao,Wu, Xiaofang,Guo, Fengzhe,Tang, Zi-Long,Xiao, Jing
supporting information, p. 4314 - 4317 (2021/07/16)
A general and efficient iodine-promoted chlorination of amides and esters with phosphorus trichloride is described. For the first time. Various inactivated amides including secondary and tertiary amides were directly converted to the corresponding acid chlorides in one-step. The substrate scope of methyl esters including aromatic and aliphatic esters was also explored under this system. This method is simple, scalable and wide in scope, which provides an approach to preparation of these acid chlorides.
Carbon dots as photocatalysts for organic synthesis: Metal-free methylene-oxygen-bond photocleavage
Cailotto, Simone,Negrato, Matteo,Daniele, Salvatore,Luque, Rafael,Selva, Maurizio,Amadio, Emanuele,Perosa, Alvise
supporting information, p. 1145 - 1149 (2020/03/11)
We report for the first time that irradiation of four different citric acid-derived carbon dots (CDs), in the absence of any other redox mediators, promotes an organic reaction. In this proof-of-concept study methylene-oxygen bond reductive photocleavage in N-methyl-4-picolinium esters is demonstrated. Cyclic voltammetry and UV-Vis spectra of the CDs and of the esters indicate that photocleavage reactivity correlates with the redox properties and the relative energies expressed in the Fermi scale. A photo-fragmentation mechanism is proposed. This study offers a new possibility to employ inexpensive and readily available CDs to promote photo-organic reactions.
Achiral Derivatives of Hydroxamate AR-42 Potently Inhibit Class i HDAC Enzymes and Cancer Cell Proliferation
Tng, Jiahui,Lim, Junxian,Wu, Kai-Chen,Lucke, Andrew J.,Xu, Weijun,Reid, Robert C.,Fairlie, David P.
, p. 5956 - 5971 (2020/06/05)
AR-42 is an orally active inhibitor of histone deacetylases (HDACs) in clinical trials for multiple myeloma, leukemia, and lymphoma. It has few hydrogen bond donors and acceptors but is a chiral 2-arylbutyrate and potentially prone to racemization. We report achiral AR-42 analogues incorporating a cycloalkyl group linked via a quaternary carbon atom, with up to 40-fold increased potency against human class I HDACs (e.g., JT86, IC50 0.7 nM, HDAC1), 25-fold increased cytotoxicity against five human cancer cell lines, and up to 70-fold less toxicity in normal human cells. JT86 was ninefold more potent than racAR-42 in promoting accumulation of acetylated histone H4 in MM96L melanoma cells. Molecular modeling and structure-activity relationships support binding to HDAC1 with tetrahydropyran acting as a hydrophobic shield from water at the enzyme surface. Such potent inhibitors of class I HDACs may show benefits in diseases (cancers, parasitic infections, inflammatory conditions) where AR-42 is active.
Direct meta-C?H Perfluoroalkenylation of Arenes Enabled by a Cleavable Pyrimidine-Based Template
Brochetta, Massimo,Borsari, Tania,Bag, Sukdev,Jana, Sadhan,Maiti, Siddhartha,Porta, Alessio,Werz, Daniel B.,Zanoni, Giuseppe,Maiti, Debabrata
supporting information, p. 10323 - 10327 (2019/07/18)
The development of efficient and mild methods for the synthesis of organofluorine compounds is of foremost interest in various fields of chemistry. A direct pyrimidine-based selective meta-C?H perfluoroalkenylation of arenes involving several commercially
Visible light-induced transformation of aldehydes to esters, carboxylic anhydrides and amides
Gaspa, Silvia,Raposo, Inês,Pereira, Leonor,Mulas, Gabriele,Ricci, Pier Carlo,Porcheddu, Andrea,De Luca, Lidia
supporting information, p. 10711 - 10715 (2019/07/15)
A transition metal- and organophotocatalyst free synthesis of esters, carboxylic anhydrides and amides from aldehydes induced by visible-light has been reported. The proposed methodology can be carried out by the use of sunlight or artificial visible light as a blue LED source. The methodology has a very broad applicability and the desired products are obtained in very satisfactory yields.
Preparation technology of atorvastatin
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Paragraph 0018; 0019; 0024; 0025; 0030; 0031; 0036; 0037, (2017/08/27)
The invention discloses preparation technology of atorvastatin. The preparation technology comprises the following steps: a first step, the reaction of phenylacetic acid and thionyl chloride is carried out in order to obtain phenylacetyl chloride; a second step, the Friedel-Crafts acylation reaction of phenylacetyl chloride and fluorobenzene is carried out under the action of catalyst, in order to obtain 4-fluorophenyl acetophenone; a third step, 4-fluorophenyl acetophenone is brominated and the brominated 4-fluorophenyl acetophenone is reacted with N-phenyl-isobutyloylacetamide in order to obtain M-4; a fourth step, a reaction is carried out for M-4 and ATS-9 in a cyclohexane, toluene or a mixed solvent of cyclohexane and toluene, pivalic acid is used for catalysis, and a condensation product is obtained. Phenylacetyl chloride and fluorobenzene are reacted in a catalytic action of zeolite molecular sieve, a complexation reaction of the catalyst and products is avoided, reaction yield is improved, and side reactions are few in order to facilitate purification; post-treatment can be carried out for excess M-4 for recycling and reusing, reaction yield is improved, mole proportion of M-4 to ATS-9 and the addition amount of pivalic acid can be adjusted, and final yield of the reaction is improved.
An anti-choline medicine preparation method of atropine sulfate
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Paragraph 0033; 0034, (2017/03/08)
The invention provides a synchronizing method of atropine sulphate. The method is characterized in that hydrolyzing methyl phenoxyacetate (II) is hydrolyzed to obtain a compound (III); the compound (III) and thionyl chloride are subjected to acylation reaction to obtain a compound (IV); the compound (IV) and 8-methyl-8-azabicyclo[3.2.1]oct-3-alchol are subjected to condensation reaction to obtain a compound (V); the compound (V) and paraformaldehyde are used for producing atropine (VI) under an alkaline condition; the atropine (VI) is salified under an acidic condition to obtain the atropine sulphate (I). The preparation method is simple in technology, high in yield, high in purity, low in monomer impurity and easy for industrial production.
