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The Journal of Organic Chemistry Dec 2021We recently reported the incorporation of diazirine photo-cross-linkers onto the -GlcNAc posttranslational modification in mammalian cells, enabling the identification...
We recently reported the incorporation of diazirine photo-cross-linkers onto the -GlcNAc posttranslational modification in mammalian cells, enabling the identification of binding partners of -GlcNAcylated proteins. Unfortunately, the syntheses of the diazirine-functionalized substrates have exhibited inconsistent yields. We report a robust and stereoselective synthesis of cell-permeable GlcNAc-1-phosphate esters based on the use of commercially available bis(diisopropylamino)chlorophosphine. We demonstrate this approach for two diazirine-containing GlcNAc analogues, and we report the cellular incorporation of these compounds into glycoconjugates to support photo-cross-linking applications.
Topics: Acetylglucosamine; Animals; Diazomethane; Glycoconjugates; Phosphates; Proteins
PubMed: 34618463
DOI: 10.1021/acs.joc.1c01781 -
Iranian Journal of Pharmaceutical... 2021A group of Novel phenylhydrazone derivatives of ethyl acetoacetate was synthesized and evaluated for their antiplatelet activities. Fourteen ethyl acetoacetate...
A group of Novel phenylhydrazone derivatives of ethyl acetoacetate was synthesized and evaluated for their antiplatelet activities. Fourteen ethyl acetoacetate phenylhydrazone derivatives were synthesized using the diazonium salt of various aromatic primary amines with good yields and purity. The structure of the final compounds was confirmed and approved by spectroscopic techniques such as HNMR, FTIR, and ESI-Mass. We examined the antiplatelet activity of the derivatives against Arachidonic Acid (AA) and Adenosine Diphosphate (ADP) as platelet aggregation inducers. The final results indicated the acceptable potency for different derivatives. In this regard, -hydroxyphenylhydrazine derivative of ethyl acetoacetate has the best activity among all derivatives, both on AA and ADP pathways. It seems that the derivatives with electron-releasing substituents (hydroxyl, methoxy, and methyl group) have better inhibition activities against the aggregation induced by AA. In contrast, those with an electron-withdrawing group showed a significant decrease in their potency. Based on the results of this study, we would proceed with further assessments both and to get success in introducing some new antiplatelet agents to the clinic.
PubMed: 34567164
DOI: 10.22037/ijpr.2020.114123.14674 -
Scientific Reports Sep 2021The SARS-CoV-2 pandemic has highlighted the weaknesses of relying on single-use mask and respirator personal protective equipment (PPE) and the global supply chain that...
The SARS-CoV-2 pandemic has highlighted the weaknesses of relying on single-use mask and respirator personal protective equipment (PPE) and the global supply chain that supports this market. There have been no major innovations in filter technology for PPE in the past two decades. Non-woven textiles used for filtering PPE are single-use products in the healthcare environment; use and protection is focused on preventing infection from airborne or aerosolized pathogens such as Influenza A virus or SARS-CoV-2. Recently, C-H bond activation under mild and controllable conditions was reported for crosslinking commodity aliphatic polymers such as polyethylene and polypropylene. Significantly, these are the same types of polymers used in PPE filtration systems. In this report, we take advantage of this C-H insertion method to covalently attach a photosensitizing zinc-porphyrin to the surface of a melt-blow non-woven textile filter material. With the photosensitizer covalently attached to the surface of the textile, illumination with visible light was expected to produce oxidizing O/ROS at the surface of the material that would result in pathogen inactivation. The filter was tested for its ability to inactivate Influenza A virus, an enveloped RNA virus similar to SARS-CoV-2, over a period of four hours with illumination of high intensity visible light. The photosensitizer-functionalized polypropylene filter inactivated our model virus by 99.99% in comparison to a control.
Topics: COVID-19; Diazomethane; Light; Photosensitizing Agents; Polypropylenes; SARS-CoV-2
PubMed: 34561486
DOI: 10.1038/s41598-021-98280-6 -
Clinical Cancer Research : An Official... Dec 2021Pyruvate kinase M2 (PKM2) catalyzes the final step in glycolysis, a key process of cancer metabolism. PKM2 is preferentially expressed by glioblastoma (GBM) cells with...
PURPOSE
Pyruvate kinase M2 (PKM2) catalyzes the final step in glycolysis, a key process of cancer metabolism. PKM2 is preferentially expressed by glioblastoma (GBM) cells with minimal expression in healthy brain. We describe the development, validation, and translation of a novel PET tracer to study PKM2 in GBM. We evaluated 1-((2-fluoro-6-[F]fluorophenyl)sulfonyl)-4-((4-methoxyphenyl)sulfonyl)piperazine ([F]DASA-23) in cell culture, mouse models of GBM, healthy human volunteers, and patients with GBM.
EXPERIMENTAL DESIGN
[F]DASA-23 was synthesized with a molar activity of 100.47 ± 29.58 GBq/μmol and radiochemical purity >95%. We performed initial testing of [F]DASA-23 in GBM cell culture and human GBM xenografts implanted orthotopically into mice. Next, we produced [F]DASA-23 under FDA oversight, and evaluated it in healthy volunteers and a pilot cohort of patients with glioma.
RESULTS
In mouse imaging studies, [F]DASA-23 clearly delineated the U87 GBM from surrounding healthy brain tissue and had a tumor-to-brain ratio of 3.6 ± 0.5. In human volunteers, [F]DASA-23 crossed the intact blood-brain barrier and was rapidly cleared. In patients with GBM, [F]DASA-23 successfully outlined tumors visible on contrast-enhanced MRI. The uptake of [F]DASA-23 was markedly elevated in GBMs compared with normal brain, and it identified a metabolic nonresponder within 1 week of treatment initiation.
CONCLUSIONS
We developed and translated [F]DASA-23 as a new tracer that demonstrated the visualization of aberrantly expressed PKM2 for the first time in human subjects. These results warrant further clinical evaluation of [F]DASA-23 to assess its utility for imaging therapy-induced normalization of aberrant cancer metabolism.
Topics: Animals; Brain Neoplasms; Diazonium Compounds; Glioblastoma; Glycolysis; Humans; Mice; Positron-Emission Tomography; Pyruvate Kinase; Sulfanilic Acids
PubMed: 34475101
DOI: 10.1158/1078-0432.CCR-21-0544 -
Molecular Diversity Jun 2022Metal-catalyzed reactions play a vital part to construct a variety of pharmaceutically important scaffolds from past few decades. To carry out these reactions under mild... (Review)
Review
Metal-catalyzed reactions play a vital part to construct a variety of pharmaceutically important scaffolds from past few decades. To carry out these reactions under mild conditions with low-cost easily available precursors, various new methodologies have been reported day by day. Sandmeyer reaction is one of these, first discovered by Sandmeyer in 1884. It is a well-known reaction mainly used for the conversion of an aryl amine to an aryl halide in the presence of Cu(I) halide via formation of diazonium salt intermediate. This reaction can be processed with or without copper catalysts for the formation of C-X (X = Cl, Br, I, etc.), C-CF/CF, C-CN, C-S, etc., linkages. As a result, corresponding aryl halides, trifluoromethylated compounds, aryl nitriles and aryl thioethers can be obtained which are effectively used for the construction of biologically active compounds. This review article discloses various literature reports about Sandmeyer-related transformations developed during 2000-2021 which give different ideas to synthetic chemists about further development of new and efficient protocols for Sandmeyer reaction. An updated compilation of new approaches for Sandmeyer reaction is described in this review to construct a variety of carbon-halogen, carbon-phosphorous, carbon-sulfur, carbon-boron etc. linkages.
Topics: Amines; Carbon; Catalysis; Copper; Molecular Structure
PubMed: 34417715
DOI: 10.1007/s11030-021-10295-3 -
Chemistry (Weinheim An Der Bergstrasse,... Oct 2021Although incorporation of photo-activatable lipids into membranes potentially opens up novel avenues for investigating interactions with proteins, the question of...
Although incorporation of photo-activatable lipids into membranes potentially opens up novel avenues for investigating interactions with proteins, the question of whether diazirine-modified lipids are suitable for such studies, remains under debate. Focusing on the potential for studying lipid/peptide interactions by cross-linking mass spectrometry (XL-MS), we developed a diazirine-modified lipid (DiazPC), and examined its behaviour in membranes incorporating the model α-helical peptide LAVA20. We observed an unexpected backfolding of the diazirine-containing stearoyl chain of the lipid. This surprising behaviour challenges the potential application of DiazPC for future XL-MS studies of peptide and protein/lipid interactions. The observations made for DiazPC most likely represent a general phenomenon for any type of membrane lipids with a polar moiety incorporated into the alkyl chain. Our finding is therefore of importance for future protein/lipid interaction studies relying on modified lipid probes.
Topics: Cross-Linking Reagents; Diazomethane; Mass Spectrometry; Membrane Lipids; Peptides
PubMed: 34406694
DOI: 10.1002/chem.202102048 -
ACS Chemical Biology Aug 2021Aliphatic diazirine analogues of cholesterol have been used previously to elaborate the cholesterol proteome and identify cholesterol binding sites on proteins....
Aliphatic diazirine analogues of cholesterol have been used previously to elaborate the cholesterol proteome and identify cholesterol binding sites on proteins. Cholesterol analogues containing the trifluoromethylphenyl diazirine (TPD) group have not been reported. Both classes of diazirines have been prepared for neurosteroid photolabeling studies and their combined use provided information that was not obtainable with either diazirine class alone. Hence, we prepared cholesterol TPD analogues and used them along with previously reported aliphatic diazirine analogues as photoaffinity labeling reagents to obtain additional information on the cholesterol binding sites of the pentameric ligand-gated ion channel (GLIC). We first validated the TPD analogues as cholesterol substitutes and compared their actions with those of previously reported aliphatic diazirines in cell culture assays. All the probes bound to the same cholesterol binding site on GLIC but with differences in photolabeling efficiencies and residues identified. Photolabeling of mammalian (HEK) cell membranes demonstrated differences in the pattern of proteins labeled by the two classes of probes. Collectively, these date indicate that cholesterol photoaffinity labeling reagents containing an aliphatic diazirine or TPD group provide complementary information and will both be useful tools in future studies of cholesterol biology.
Topics: Alkynes; Binding Sites; Cholesterol; Cyanobacteria; Diazomethane; Fluorescent Dyes; Ligand-Gated Ion Channels; Molecular Docking Simulation; Molecular Dynamics Simulation; Photoaffinity Labels; Protein Binding
PubMed: 34355883
DOI: 10.1021/acschembio.1c00364 -
TheScientificWorldJournal 2021This article includes the synthesis of heterocyclic azo dye of theophylline by coupling diazonium salt of 4-chloroaniline with theophylline which is, namely,...
This article includes the synthesis of heterocyclic azo dye of theophylline by coupling diazonium salt of 4-chloroaniline with theophylline which is, namely, 8-(1-(4-chlorophenyl)azo)theophylline (CPAT). The complexes of cobalt and nickel were prepared by reacting their ions with CPAT ligand in ethanol under 1 : 2 ratio metal-ligand. The CPAT ligand and its complexes were characterized by elemental analysis, infrared spectrometry, electronic absorption spectroscopy, molar conductivity, and magnetic moment. The cobalt and nickel complexes show octahedral geometry having general formula [M(CPAT)Cl]. This article addresses the properties of CPAT dye such as photochromic properties. The CPAT dye exhibited obvious and desired changes under irradiation with visible light (405 nm), high sensitive for pH changes which refer to its ability to be analysis indicator. CPAT dye exhibited solvatochromic properties presenting red shift with polar solvent. The CPAT and its complexes show interesting antibiological activities towards and bacteria and fungi.
Topics: Anti-Infective Agents; Aspergillus; Azo Compounds; Escherichia coli; Hydrogen-Ion Concentration; Light; Magnetic Resonance Spectroscopy; Microbial Sensitivity Tests; Staphylococcus aureus; Theophylline; X-Ray Diffraction
PubMed: 34335115
DOI: 10.1155/2021/9943763 -
Current Protocols Jul 2021This protocol enables identification of the interaction partners of O-GlcNAcylated proteins. The method involves the introduction of the diazirine photocrosslinker onto...
This protocol enables identification of the interaction partners of O-GlcNAcylated proteins. The method involves the introduction of the diazirine photocrosslinker onto the O-GlcNAc modification within living cells. The photocrosslinker is activated by UV light to yield covalent crosslinking between O-GlcNAcylated proteins and neighboring molecules. The binding partners can be further characterized by immunoblot or proteomics mass spectrometry methods. The benefits of using the photocrosslinker include the capacity to trap low-affinity binding interactions and the ability to selectively target the interaction partners of the O-GlcNAcylated form of the protein of interest. © 2021 Wiley Periodicals LLC. Basic Protocol 1: In-cell production and crosslinking of O-GlcNDAzylated proteins Basic Protocol 2: Immunoblot analysis to assess O-GlcNDAz crosslinking Support Protocol: Detection of UDP-GlcNDAz from cell lysates.
Topics: Acetylglucosamine; Diazomethane; Mass Spectrometry; Protein Processing, Post-Translational; Proteins
PubMed: 34288588
DOI: 10.1002/cpz1.201 -
Nature Chemistry Jul 2021DNA-protein interactions regulate critical biological processes. Identifying proteins that bind to specific, functional genomic loci is essential to understand the...
DNA-protein interactions regulate critical biological processes. Identifying proteins that bind to specific, functional genomic loci is essential to understand the underlying regulatory mechanisms on a molecular level. Here we describe a co-binding-mediated protein profiling (CMPP) strategy to investigate the interactome of DNA G-quadruplexes (G4s) in native chromatin. CMPP involves cell-permeable, functionalized G4-ligand probes that bind endogenous G4s and subsequently crosslink to co-binding G4-interacting proteins in situ. We first showed the robustness of CMPP by proximity labelling of a G4 binding protein in vitro. Employing this approach in live cells, we then identified hundreds of putative G4-interacting proteins from various functional classes. Next, we confirmed a high G4-binding affinity and selectivity for several newly discovered G4 interactors in vitro, and we validated direct G4 interactions for a functionally important candidate in cellular chromatin using an independent approach. Our studies provide a chemical strategy to map protein interactions of specific nucleic acid features in living cells.
Topics: Alkynes; Aminoquinolines; Cell Line, Tumor; Cross-Linking Reagents; DNA; DNA-Binding Proteins; Diazomethane; G-Quadruplexes; HEK293 Cells; Humans; Ligands; Proof of Concept Study; Protein Binding; Ultraviolet Rays
PubMed: 34183817
DOI: 10.1038/s41557-021-00736-9