Nitro Benzyl Research Articles

Synthesis and antioxidant properties of novel hybrid molecules containing gallic acid and thiazolidinone moieties

Thiazolidinones, are characterized by a thiazolidine ring structure, have highly biological applications. So, novel hybrid thiazolidinone moieties containing gallic acid were synthesized via cyclo-condensation process or standard Knoevenagel reactions. Hydrazineyl-thiazol-4(5H)-one 2 derivative was synthesized to condensed with benzaldehydes to afford benzylidene thiazolidinone derivatives 3a-c. Also, the product 2 reacted with benzyl bromide or nitro benzyl bromide to give their corresponding methylene active derivatives 4a,b which were readily reacted with aromatic aldehydes to produce 5-arylidene derivatives 5a-f via Knoevenagel reactions. The new thiazolidine derivatives were elucidated according to their spectroscopic and elemental analyses. Two thiazolidinone derivatives 4a,b were elucidated via X-ray analysis. Also, antioxidant activity of the new products were run by DPPH assay and in comparison with reference antioxidants (ascorbic acid and BHT). The results revealed that eight compounds was higher than BHT and was increasing in the following order 4a < 5f < 5a< 3c < 5b < 5d < 3a< 5c. The antioxidant activity of ascorbic acid was higher than all compounds in which compound 5c was very close in its activity with the ascorbic acid.

Water-Stable, Eight-electron Acceptor Drives Anion⋅⋅⋅Water Assisted Tunable Ionic Self-Assembly and Proton Conduction.

Organic π-scaffolds are being envisaged for new-age electron- and ion-responsive materials that can accumulate electrons as well as transport proton. However, such systems are extremely rare as electron-deficient scaffolds are unstable in aqueous solution. Here we detail the synthesis of a water-stable core-naphthalenediimide-nitrobenzyl-viologen based tetra-cation, which accumulates up to eight-electrons within an exceptionally narrow potential window of +0.05 V and -1.12 V. The supramolecular interactions and the ensuing ionic framework are tunable based on the three anions, e. g., Cl-, Br- and PF6 -, that are investigated in this work. The ionic framework is formed and supported by a range of H-bonds, in which, the nitro benzyl groups act as pillars connecting the 1D water-tapes and the halide anions. The water molecules are hydrogen-bonded with the halide anions and bestow a facile pathway for the proton conduction, with proton conductivity up to 3.19×10-3 S cm-1. In contrast, the ionic assembly formed by the lipophilic PF6 - anions do not host the water tapes and consequently the proton conductivity is found to be four orders of magnitude lower. This is a unique example, whereby proton conductivity is realized and is tunable within a highly electron-deficient, eight-electron acceptor, water-stable ionic supramolecular system.

Para-Fluoro-Thiol Reaction on Anchor Layers Grafted from an Aryldiazonium Salt: A Tool for Surface Functionalization with Thiols.

A new coupling reaction, the para-fluoro-thiol (PFT) reaction, activated by base at room temperature, is reported for carbon surface functionalization. 4-Nitrothiophenol (4-NTP) and (3-nitrobenzyl)mercaptan (3-NBM) were coupled to pentafluorophenyl (F5-Ph) anchor layers grafted from the aryldiazonium ion formed in situ. The relative yields of the PFT reactions, estimated from the electrochemical responses of coupled nitrophenyl (NP) and nitrobenzyl (NB) groups, depended on the nucleophilicity of the thiolate and the strength of the base. The highest surface concentration (4.6 × 10-10 mol cm-2) was obtained using 3-NBM in the presence of [Bu4N]OH; this concentration corresponds to the maximum that is typically achieved for other high-yielding coupling reactions at aryldiazonium ion anchor layers. The PFT reaction is expected to be applicable to the numerous thiol derivatives commonly restricted to self-assembled monolayer (SAM) formation at gold and other noble metals, thereby opening a simple new approach for interface design on carbon substrates. The strategy may also have advantages for modification of gold surfaces: the layer prepared by coupling 3-NBM to F5-Ph films on gold was found to be more stable to storage under ambient conditions than self-assembled monolayers of 3-NBM.

On-demand and tunable dual wavelength release of antibody using light-responsive hydrogels.

There has been an increased interest in the use of protein therapeutics, especially antibodies, for the treatment of a variety of diseases due to their high specificity to tissues and biological pathways of interest. However, the use of antibodies can be hindered by physical aggregation, degradation, and diffusion when injected in vivo leading to the need for antibody-releasing depots for the controlled and localized delivery within tissues of interest. Here, we investigated photolabile hydrogel chemistries for creating on-demand and tunable antibody release profiles. Innovative, scalable synthetic procedures were established and applied for fabricating hydrogels with nitrobenzyl (NB) and coumarin (CMR) photolabile crosslinks that responded to clinically relevant doses of long-wavelength UV and short-wavelength visible light. This synthetic procedure includes a route to make a CMR linker possessing two functional handles at the same ring position with water-stable bonds. The photocleavage properties of NB and CMR crosslinked hydrogels were characterized, as well as their potential for translational studies by degradation through pig skin, a good human skin mimic. The mechanism of hydrogel degradation, bulk versus surface eroding, was determined to be dependent on the wavelength of light utilized and the molar absorptivity of the different photolabile linkers, providing a facile means for altering protein release upon hydrogel degradation. Further, the encapsulation and on-demand release of a model monoclonal antibody was demonstrated, highlighting the ability to control antibody release from these hydrogels through the application of light while retaining its bioactivity. In particular, the newly designed CMR hydrogels undergo surface erosion-based protein release using visible light, which is more commonly used clinically. Overall, this work establishes scalable syntheses and relevant pairings of formulation-irradiation conditions for designing on-demand and light-responsive material systems that provide controlled, tunable release of bioactive proteins toward addressing barriers to preclinical translation of light-based materials and ultimately improving therapeutic regimens.

Effect of Nitro Groups on Desulfurization Efficiency of Benzyl-Substituted Imidiazolium-Based Ionic Liquids: Experimental and Computational Approach

In the maneuver to achieve desulfurization, we have explored various nitro-substituted positional isomeric imidazolium-based aprotic ionic liquids (ILs). Ortho-, meta-, and para-substituted nitro benzyl group-aided imidazolium-based ILs were synthesized and used to understand the extractive desulfurization (EDS) efficiency of fuels. ILs chosen for the experiment were optimized using the B3LYP method and 6-311(++)g(d,p) of Gaussian 09, and their interactions with thiophene derivatives were analyzed using the integrated electric field polar continuum model solvation. Free energy of solvation provided qualitative information about the ability of ILs to achieve desulfurization. Parameters affecting the efficiency of synthesized ILs were perused, such as the effect of IL volume, concentration, duration of rotation, and other such parameters. Lewis acidity, availability of the Lewis acidic site and π–π interaction influenced the EDS efficiency of ILs.

Reduction-Responsive DNA Duplex Containing O 6-Nitrobenzyl-Guanine.

Stimuli-controlled structural transitions of nucleic acids have received growing attentions owing to their potential applications in the fields of chemical and synthetic biology. Here, we describe the development of reduction-responsive deoxyribonucleic acid (DNA) duplexes, in which guanine rings bearing a reduction-responsive cleavable nitrobenzyl (NB) group at the O6 position (GNB) are introduced at defined positions. We demonstrate that the artificial NB group can be removed in response to reduction stimulus without the dissociation of the intermolecular duplex structure, which comprises a G-quadruplex forming nucleic acid strand with one GNB and its complementary sequence with one mismatch pair. Meanwhile, another duplex that comprised a G-quadruplex forming nucleic acid strand with two GNB and its complementary sequence with three mismatch pairs exhibited reduction-responsive structural transitions from intermolecular duplex to intramolecular quadruplex. These findings might be useful for the development of DNA architectures endowed with reduction-responsive functions.

SINTESIS SENYAWA ANTIMALARIA BARU TURUNAN FENANTROLIN N-(2-NITROBENZIL)-1,10-FENANTROLINIUM IODIDA DAN (1) N-(4-NITROBENZIL)-1,10-FENANTROLINIUM IODIDA

Malaria is a global health problem, especially in the tropics. Efforts to decrease the incidence of malaria plagued the plasmodium resistance to existing antimalarial drugs. Benzyl Phenanthrolium Iodide derivates have been proved has antimalarial activity. The aim of this study is synthesis the nitro benzyl phenanthrolium.The research that has been done was the synthesis of (1)-N-(2-nitrobenzyl) phenantrolium iodide and(1)-N-(4-nitrobenzyl)-1,10-phenantrolium iodide. Synthesis of (1)-N-(2-nitrobenzyl)-1,10-phenantrolium iodide through a two-steps reaction SN-2 is the reaction of (1)N-(2- nitrobenzyl) chloride and potassium iodide followed by reaction phenantroline 1:10 monohydrate, whether the second product was 4-nitrobenzil bromida as starting material. The reaction were started by reflucting the nitro subtituted benzil halida with potassium iodide for 1 hour, yielded nitro subtituted benzyl iodide. Then followed by reflucting nitro substituted benzyl iodide with 1,10-phenanthroline for 11 hours. The final product isolated and purificated by suitable solvent. The melting point was conducted by melting poin apparatus. The structures of product was characterized by IR and UV-Vis spectroscopy.Results obtained in the form of thick liquid light yellow with a melting point of 54.2-63.5oC. While the compound (1)-N-(4-nitrobenzyl)-1,10-phenantrolium iodide is synthesized from 4-nitrobenzylbromide and potassium iodide followed by reaction phenantroline 1:10 monohydrate. Synthesis results in the form of pale yellow crystals with a melting point of 221–225oC . The resulting yield of 32.87%. The interpretation of UV-Vis and Infra red spectras indicated that nitro benzyl iodide have been condensed with 1,10 phenantroline as the end of the product.

Electrochemically reduced titanocene dichloride as a catalyst of reductive dehalogenation of organic halides

We have studied a reaction between the reduced form of titanocene dichloride (Cp 2TiCl 2) and a group of organic halides: benzyl derivatives (4-X C 6H 4CH 2Cl, X = H, NO 2, CH 3; 4-X C 6H 4CH 2Br, X = H, NO 2, PhC(O); 4-X C 6H 4CH 2SCN, X = H, NO 2) as well as three aryl halides (4-NO 2C 6H 4Hal, Hal = Cl, Br; 4-CH 3O-C 6H 4Cl). It has been shown that the electrochemical reduction of Cp 2TiCl 2 in the presence of these benzyl halides leads to a catalytic cycle resulting in the reductive dehalogenation of these organic substrates to yield mostly corresponding toluene derivatives as the main product. No dehalogenation has been observed for aryl derivatives. Based on electrochemical data and digital simulation, possible schemes of the catalytic process have been outlined. For non-substituted benzyl halides halogen atom abstraction is a key step. For the reaction of nitrobenzyl halides the complexation of Ti(III) species with the nitro group takes place, with the electron transfer from Ti(III) to this group (owing to its highest coefficient in LUMO of the nitro benzyl halide) followed by an intramolecular dissociative electron redistribution in the course of the heterolytic C Hal bond cleavage. The results for reduced titanocene dichloride centers immobilized inside a polymer film showed that the catalytic reductive dehalogenation of the p-nitrobenzyl chloride does occur but with a low efficiency because of the partial deactivation of the film due to the blocking of the electron charge transport between the electrode and catalytic centers.

Solid-Phase Synthesis ofN-Alkylated Naltrindoles Using a 3-Nitrobenzyl Safety-Catch Linker

We describe an effective solid-phase synthesis of N-substituted naltrindoles using a nitro benzyl safety-catch linker. The linker is stable to both strongly acidic and basic conditions and is cleaved under mildly acidic conditions after conversion of the nitro group to an amide group. Using the linker, a combinatorial synthesis of N-substituted naltrindoles involving the Fischer indole ­synthesis and N-alkylation was accomplished to provide 16 N-substituted naltrindoles.