6322-56-1Relevant academic research and scientific papers
Light-Controlled Tyrosine Nitration of Proteins
Long, Tengfang,Liu, Lei,Tao, Youqi,Zhang, Wanli,Quan, Jiale,Zheng, Jie,Hegemann, Julian D.,Uesugi, Motonari,Yao, Wenbing,Tian, Hong,Wang, Huan
supporting information, p. 13414 - 13422 (2021/05/12)
Tyrosine nitration of proteins is one of the most important oxidative post-translational modifications in vivo. A major obstacle for its biochemical and physiological studies is the lack of efficient and chemoselective protein tyrosine nitration reagents. Herein, we report a generalizable strategy for light-controlled protein tyrosine nitration by employing biocompatible dinitroimidazole reagents. Upon 390 nm irradiation, dinitroimidazoles efficiently convert tyrosine residues into 3-nitrotyrosine residues in peptides and proteins with fast kinetics and high chemoselectivity under neutral aqueous buffer conditions. The incorporation of 3-nitrotyrosine residues enhances the thermostability of lasso peptide natural products and endows murine tumor necrosis factor-α with strong immunogenicity to break self-tolerance. The light-controlled time resolution of this method allows the investigation of the impact of tyrosine nitration on the self-assembly behavior of α-synuclein.
Magnesium tetrapyrazinoporphyrazines: Tuning of the pKa of red-fluorescent pH indicators
Karlikova, Martina,Cermakova, Veronika,Demuth, Jiri,Valer, Vojtech,Miletin, Miroslav,Novakova, Veronika,Zimcik, Petr
supporting information, p. 6162 - 6173 (2019/05/16)
Magnesium(ii) tetrapyrazinoporphyrazines (TPyzPzs) are excellent red fluorophores (λF ~ 663 nm, ΦF ~ 0.53 in THF). In this work, a series of magnesium(ii) complexes of unsymmetrical TPyzPzs bearing one or two phenol substituents was prepared. Suitable substitutions on the phenolic moiety tuned its pKa in the range of 5.5 to 13. Deprotonation of the phenolic group at higher pH induced a strong donor (phenolate) in the macrocycle that led to pH-dependent quenching of the red fluorescence of these indicators. pH sensing was proved in water solutions after the incorporation of TPyzPzs into two delivery systems-microemulsions and liposomes. The latter also serves as a simple model of biomembranes. Finally, a wavelength-ratiometric probe was constructed by the incorporation of a TPyzPz indicator and lipophilic pH-nonsensitive BODIPY dye into liposomes. Synthetic precursors for TPyzPzs, substituted pyrazine-2,3-dicarbonitriles, also represent donor-acceptor systems and the pH-dependent changes in absorption spectra may be easily visible to the naked eye.
Yttrium Nitrate mediated Nitration of Phenols at room temperature in Glacial Acetic acid
Mondal, Mohabul A,Mandal, Debashis,Mitra, Kanchan
, p. 39 - 43 (2017/01/24)
Rapid nitration of electron rich phenols using Y(NO 3) 3.6H 2O in glacial acetic acid at room temperature was observed with good yield. The method allows nitration of phenols without oxidation, and isolation of nitration product in a rapid and simple way. The described method is selective for phenols. [Figure not available: see fulltext.]
Synthesis, protease inhibition, and antileishmanial activity of new benzoxazoles derived from acetophenone or benzophenone and synthetic precursors
Folquitto, Laís R. S.,Nogueira, Priscila F.,Espuri, Patrícia F.,Gontijo, Vanessa S.,de Souza, Thiago B.,Marques, Marcos J.,Carvalho, Diogo T.,Júdice, Wagner A. S.,Dias, Danielle F.
, p. 1149 - 1159 (2017/05/04)
Abstract: This work reports the synthesis, protease inhibition, and antileishmanial activity of ten benzoxazole derivatives, which were obtained in a three-step synthetic route from 4-hydroxy-acetophenone and 4-hydroxy-benzophenone. These benzoxazoles, the synthetic intermediates, and the starting ketones were evaluated for their inhibitory effect on the activity of cysteine (papain, rCPB2.8, and rCPB3.0) and serine (trypsin) proteases. All compounds showed significant values of IC50 against these enzymes (in the range of 0.0086–0.7612 μM for papain and 0.0075–0.5032 μM for trypsin), being more active than the standard inhibitors (1.7821 and 7.2318 μM, for E64 and TLCK, respectively). Following, all compounds were evaluated in vitro for their leishmanicidal activity against promastigote form of Leishmania amazonensis. The most active compounds were further evaluated against amastigote form and for its toxicity against murine macrophages. The benzoxazole 4d, a benzophenone derivative, and the intermediate 4-hydroxy-3-nitroacetophenone 2b showed significant antileishmanial activity (IC50 = 90.3 μM and IC50 = 130.9 μM, respectively) with selectivity indexes (5.22 and 18.09, respectively) compared to or better than those of two established leishmanicidal drugs, pentamidine (0.58) and amphotericin B (5.31). Graphical Abstract: [InlineMediaObject not available: see fulltext.].
Pharmacophore combination as a useful strategy to discover new antitubercular agents
Rana, Dharmarajsinh N.,Chhabria, Mahesh T.,Shah, Nisha K.,Brahmkshatriya, Pathik S.
, p. 370 - 381 (2014/03/21)
The present study is aimed at combining two well-known pharmacophores (pyrazoline and benzoxazole nucleus) to design and synthesize a series of substituted pyrazoline-based benzoxazole derivatives. In vitro antitubercular evaluation against Mycobacterium tuberculosis H37Rv, multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) strains showed that most of the target compounds displayed potent activity (MIC ~1.25-25 μg/mL) where few compounds were found to be better than isoniazid against MDR-TB (MIC = 3.25 μg/mL) and XDR-TB (MIC = 12.5 μg/mL). Cytotoxicity assay of these active compounds in VERO cell lines displayed good selectivity index. In order to gain insights into the plausible binding motifs, the target compounds were docked into enoyl-acyl carrier protein reductase, a molecular target of isoniazid. All the docked compounds occupied the same hydrophobic binding pocket and interacted mostly by dispersion interactions. Contribution of the three pharmacophoric fragments (pyrazoline, benzoxazole and aryl ring) toward protein-ligand binding was evaluated at semi empirical quantum mechanics level. The interaction energies suggested that most of the binding was governed by the benzoxaxole moiety followed by pyrazoline and aryl rings.
Design of ionic liquid 3-methyl-1-sulfonic acid imidazolium nitrate as reagent for the nitration of aromatic compounds by in situ generation of NO 2 in acidic media
Zolfigol, Mohammad A.,Khazaei, Ardeshir,Moosavi-Zare, Ahmad R.,Zare, Abdolkarim,Kruger, Hendrik G.,Asgari, Zhila,Khakyzadeh, Vahid,Kazem-Rostami, Masoud
experimental part, p. 3640 - 3645 (2012/06/15)
3-Methyl-1-sulfonic acid imidazolium nitrate ([Msim]NO3) as a new Bronsted acidic ionic liquid and nitrating agent was prepared and used for the efficient nitration of aromatic compounds (even aniline derivatives). The dramatic effect of this reagent by in situ generation of nitrogen dioxide as a radical on aromatic compounds to give nitroarenes has been studied.
Melamine-(H2SO4)3 and PVP-(H 2SO4)n as solid acids: Synthesis and application in the first mono- and di-nitration of bisphenol A and other phenols
Chehardoli, Gholamabbas,Zolfigol, Mohammad Ali,Azimi, Seyedeh Bahareh,Alizadeh, Ebadollah
experimental part, p. 827 - 830 (2012/02/14)
Melamine and poly vinylpyrrolidone (PVP) reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-(H 2SO4)3 and PVP-(H2SO 4)n. These solid acids were used for the first nitration of bisphenol A as well as other phenols in the presence of NH4NO 3. Mono- and di-nitro bisphenol A have been characterized with IR and 1H NMR techniques.
Nitration of phenolic compounds and oxidation of hydroquinones using tetrabutylammonium chromate and dichromate under aprotic conditions
Pourali, Ali Reza,Goli, Arezou
scheme or table, p. 63 - 67 (2012/01/13)
In this work, we have reported a mild, efficient and selective method for the mononitration of phenolic compounds using sodium nitrite in the presence of tetrabutylammonium dichromate (TBAD) and oxidation of hydroquinones to quinones with TBAD in CH2Cl2. Using this method, high yields of nitrophenols and quinones were obtained under neutral aprotic conditions. Tetrabutylammonium chromate (TBAC) can also be used as oxidant at same conditions. Indian Academy of Sciences.
Reaction between peroxynitrite and boronates: EPR spin-trapping, HPLC analyses, and quantum mechanical study of the free radical pathway
Sikora, Adam,Zielonka, Jacek,Lopez, Marcos,Dybala-Defratyka, Agnieszka,Joseph, Joy,Marcinek, Andrzej,Kalyanaraman, Balaraman
experimental part, p. 687 - 697 (2012/03/27)
Recently, we showed that peroxynitrite (ONOO-) reacts directly and rapidly with aromatic and aliphatic boronic acids (k ≈ 106 M-1s-1). Product analyses and substrate consumption data indicated that ONOO-/s
Selective nitration of phenols using bismuth subnitrate/charcoal in the presence of trichloroisocyanuric acid under aprotic conditions
Pourali, Ali Reza,Fatemi, Fatemeh
experimental part, p. 1283 - 1286 (2011/10/05)
A mild, efficient and regioselective method for the mononitration of phenolic compounds is described using bismuth subnitrate/charcoal in the presence of trichloroisocyanuric acid in CH2Cl2 at room temperature.
