Azine Derivatives Research Articles

Visualization of latent fingerprints using an AIE-active unsymmetrical azine: 2-Naphthol-pyrrole acrylate conjugate and its fluorescent sensing of Cu2+ and S2− ions, smartphone and logic gate applications

A novel, AIE-active unsymmetrical azine-based probe LH2 was designed and developed by simple condensation of ethyl-α-cyano-5-formyl-2-pyrroleacrylate and 1-(hydrazonomethyl)naphthalene-2-ol. The synthesized probe LH2 was characterized by NMR and mass spectrometric methods. Aggregation-induced emission (AIE) behavior of azine derivative, LH2 was examined in a DMSO-H2O mixture, where the compound displayed a weak emission in pure organic solvent DMSO, and the emission was found to be enhanced at 608 nm on increasing the water fraction owing to the occurrence of restriction of intramolecular rotation (RIR). The aggregation feature of LH2 was supported by DLS and FE-SEM studies. Further, the practical application of aggregates was established by imaging latent fingerprints (LFPs) over a TLC glass slide and other platofrms. In addition, the probe LH2 could selectively detect Cu2+ ions colorimetrically and fluorometrically in DMSO: H2O mixture over the other metal ions. More significantly, the naked eye-detectable color change of LH2 has been fruitfully integrated with an RGB color value app to make it suitable for easy on-site and real-time detection of Cu2+ ions. The LH2-Cu2+ ensemble displayed high selectivity towards S2− ion over other anions via displacement approach and such reversible On-Off-On emission characteristics were utilized for the construction of the IMPLICATION logic gate.

Green Route Synthesis and Molecular Docking of Azines Using Cellulose Sulfuric Acid under Microwave Irradiation

A novel catalytic approach for the synthesis of symmetric and asymmetric azines has been developed. The environmentally benign protocol was achieved via condensation of 1-[(2-thienyl)ethylidene]hydrazine (1) with different aromatic aldehydes 2a–h and acetyl heterocyclic compounds (4, 6, 8, 10, and 12) in the presence of cellulose sulfuric acid (CSA) as the green catalyst. These procedures offer an interesting method for the large-scale industrial manufacture of azines due to their high percentage yield, mild reaction conditions, broad substrate range, and utilization of an economical and environmentally acceptable catalyst. Additionally, the molecular docking of the products to the monoamine oxidase (MAO-A) target protein was achieved to highlight the possible binding interaction with the amino acid residues Arg51, Glu43, Gly22, Gly49, Gly443, Ala272, Ile335, and Tyr407 at the point of binding. The binding interaction energy was discovered to be (− 6.48 kcal/mol) for the protein MAO-A (PDB ID: 2Z5X). The most effective azine derivatives 7 and 13 revealed some major conserved interactions between the MAO-A protein’s binding site amino acid residues and the PDB co-crystal ligand 2Z5X. Moreover, azine derivatives 3a and 3f showed the lowest binding activity with the target MAO-A.

Synthesis of and theoretical research on some azine derivatives and investigation of their antimicrobial activities

This study includes experimental, theoretical, and antimicrobial investigations on 1-(diphenylmethylene)-2-(4-methoxybenzylidene)hydrazine (5), 1-(3,5-dimethoxybenzylidene)-2-(diphenylmethylene)hydrazine (6) and 1- (diphenylmethylene)-2-(2,3,4-trimethoxybenzylidene)hydrazine (7). The structures of the compounds synthesized by microwave method were determined by spectroscopic methods and elemental analysis. Conformational analysis, ground state structure, fourier transform infrared spectra (FT-IR), and nuclear magnetic resonance (NMR) spectra of the compounds were computed using density functional theory (DFT) calculations in the theoretical research. Based on the B3LYP/6-31G(d,p) level, the conformers from the torsional barrier scanning were optimized. The B3LYP/6-311++G .(d,p) was used to determine the harmonic vibrational frequencies, potential energy distribution (PED), infrared intensities, and NMR chemical shifts of the most stable conformers. The experimental findings were compared with theoretically expected spectral data. The antibacterial activity of the prepared compounds was tested in vitro against nine bacteria and one yeast species. The antimicrobial activity of the compounds was tested by minimum inhibitory concentration (MIC) and agar well diffusion method. Compound 7 showed good activity against the bacteria and yeast, while 5 and 6 showed no antimicrobial activity. Compound 7 showed zone of inhibition values in the range of 10-15 mm against Klebsiella pneumonia, Pseudomonas aeruginosa and Salmonella typhimurium The results indicated that compound 7 was effective against bacteria.

Design, synthesis, electrochemistry and anti-trypanosomatid hit/lead identification of nitrofuranylazines.

Chagas disease and leishmaniasis are vector-borne infectious diseases affecting both humans and animals. These neglected tropical diseases can be fatal if not treated. Hundreds to thousands of new Chagas disease and leishmaniasis cases are being reported by the WHO every year, and currently available treatments are insufficient. Severe adverse effects, impractical administrations and increased pathogen resistance against current clinical treatments underscore a serious need for the development of new drugs to curb these ailments. In search for such drugs, we investigated a series of nitrofuran-based azine derivatives. Herein, we report the design, synthesis, electrochemistry, and biological activity of these derivatives against promastigotes and amastigotes of Leishmania major, and L. donovani strains, as well as epimastigotes and trypomastigotes of Trypanosoma cruzi. Two leishmanicidal early leads and one trypanosomacidal hit with submicromolar activity were uncovered and stand for further in vivo investigation in the search for new antitrypanosomatid drugs. Future objective will focus on the identification of involved biological targets with the parasites.

Rational molecular design of phenanthroimidazole–azine derivatives for efficient non-doped blue organic light-emitting diodes with low-efficiency roll-off

A family of phenanthroimidazole–azine derivatives (TrBPI, 4PyBPI, 2PyBPI, and 2PyTPI) bearing various kinds of azine acceptors (2,4-diphenyltriazine, 4,6-diphenylpyrimidine, and 2,6-diphenylpyrimidine) are successfully developed.

Deciphering swift reversal of multifaceted photodynamics of a novel pyrene appended unsymmetrical salicylaldehyde azine derivative in aqueous and protein environments

The present investigation sheds light on the judicious modulation of an external microenvironment to harvest optimal optical responses of organic functional molecules.

Synthesis and recognition behavior studies of indole derivatives

A series of new indole-based chemical sensor azine derivatives were prepared and characterized by various spectroscopic methods such as 1H NMR, mass spectra, ATR, and elemental analysis. The photophysical properties and ion recognition behavior of compound K derivatives were studied by UV–vis, photoluminescence spectroscopy, and naked-eye sensing. The absorption and emission bands of compound K derivatives were observed at 250–350 and 350–360 nm, and the emission was very low. In CH3CN solution, compound K derivatives show a highly selective “turn-on” fluorescence response to Cu2+ and CN– ions over the other competing ions such as Li+, Ca2+, Cr3+, Hg2+, Ni2+, Zn2+, Cd2+, Pb2+, and Br-, I-, HSO4-, ClO4-, and PF6-. In the presence of Cu2+ and CN– ions, new emission bands were found at 500–550 and 440–460 nm, which indicates the sensor K derivatives have a highly selective recognition behavior of Cu2+ and CN– ions. The sensing mechanism of sensors toward Cu2+ and CN– ions was studied through the 1H NMR titrations method, mass studies, photophysical spectrum, and DFT studies. When Cu2+ was coordinated, a new absorption peak of MLCT appeared at 440 nm, which involved energy release through fluorescence for the excited state. For anion recognition, CN– induced the deprotonation of the indole group, and the conjugated system was affected, which is not conducive to the process of PET. Also, the probability of excited electron density was increased in the indole group.

Heterocyclization of Bis(2-chloroprop-2-en-1-yl)sulfide in Hydrazine Hydrate-KOH: Synthesis of Thiophene and Pyrrole Derivatives.

The article is devoted to heterocyclization of bis(2-chloroprop-2-en-1-yl)sulfide which proceeds in hydrazine hydrate–alkali medium and leads to formation of thiophene and pyrrole derivatives: previously described 4,5,9,10-tetrahydrocycloocta[1,2-c;5,8-c’]dithiophene, as well as unknown hydrazone of 5-methylidene-3-methyldihydrothiophen-2-one and 1-amino-2-(propynylsulfanylpropenylsulfanyl)-3,5-dimethylpyrrole. Tentative mechanisms for the formation of the heterocyclic products are discussed. Obtained hydrazone of 5-methylidene-3-methyldihydrothiophen-2-one was used for the synthesis of a range of azine derivatives and in oxidation process with SeO2. The found reactions open up expedient approaches to the formation of various hardly accessible thiophene and pyrrole compounds from 2,3-dichloropropene and elemental sulfur as starting reagents.

Hybrid Azine Derivatives: A Useful Approach for Antimicrobial Therapy.

Nowadays, infectious diseases caused by microorganisms are a major threat to human health, mostly because of drug resistance, multi-drug resistance and extensive-drug-resistance phenomena to microbial pathogens. During the last few years, obtaining hybrid azaheterocyclic drugs represents a powerful and attractive approach in modern antimicrobial therapy with very promising results including overcoming microbial drug resistance. The emphasis of this review is to notify the scientific community about the latest recent advances from the last five years in the field of hybrid azine derivatives with antimicrobial activity. The review is divided according to the main series of six-member ring azaheterocycles with one nitrogen atom and their fused analogs. In each case, the main essential data concerning synthesis and antimicrobial activity are presented.

Structure-property relationship on aggregation-induced emission properties of simple azine-based AIEgens and its application in metal ions detection

In recent twenty years, aggregation-induced emission (AIE), due to its excellent application prospect, has aroused widespread interests. The development of novel and easy to make AIE luminogens (AIEgens) is an attractive subject. For this purpose, it is very important to study the structure-property relationship of AIEgens. Because azine derivatives are easy to synthesis and some of them have nice AIE properties, herein, a series of azine derivatives (ADs) were employed as models to study the influence of different functional groups, electronic effects and structures on the AIE properties of azine derivatives. The AIE mechanism were studied by single crystal analysis, density functional theory (DFT) calculations and so on. The results indicated that the o-hydroxyl aryl substituted azine compounds could show good AIE properties. Meanwhile, the AIE properties of o-hydroxyl aryl substituted azine compounds were also influenced by the electronic effects of the aryl groups in the azine compounds. The o-hydroxyl groups could form intramolecular hydrogen bond with imine group, which play key role to restrict the intramolecular rotation of the aryl groups and act as base stone for the AIE process of this kind compounds. The HOMO-LUMO energy gaps of o-hydroxyl substituted azine are smaller than other homologous compounds, which is agree with the proposed AIE mechanism. Finally, thanks to the AIE properties, the o-hydroxy-substituted azines could be used as efficient Al3+ and Cu2+ fluorescent chemosensors in different conditions. In addition, test strips based on AD10 has been prepared, which can conveniently detect Cu2+ in industrial wastewater. This research supplied a way for the design of novel easy to make AIEgens through simple azine derivatives.

Novel high sensitivity dual-channel chemosensor for detecting CN− based on asymmetric azine derivatives in aqueous media

A novel cyanide specifically selective and highly sensitive chemosensor HSD had been designed and synthesized. • The synthesis process of HSD is simple and environmentally friendly. • HSD is shown “naked-eye” and fluorescence “turn-off” response for CN − in solution. • It has been applied to monitor CN − in an aqueous solution. • The mechanism of action of HSD on CN − is the deprotonate. • A test strip of HSD was prepared to detect CN − quickly and easily. Specific monitoring of trace levels of poisonous ions by naked eyes is still a significant challenge in the surroundings. Herein, we developed a novel asymmetric azine dual-channel sensor (HSD) applied for selectively detecting the CN − in the aqueous media. The selectivity and sensitivity of sensor HSD for anions sensing were investigated by measuring the photophysical properties. The results show that HSD recognizes CN − with good selectivity and sensitivity, with an “off” fluorescence response and apparent color change (from colorless to yellow) under visible light and strong anti-interference to other common anions. According to fluorescence titration of sensor HSD to CN − , the detection limit was determined to be as low as 1.02 × 10 −8 M. In addition, the reaction mechanism of the probe has been studied by 1 H NMR titration and DFT theoretical calculations. Finally, the test strips were prepared and verified to be a convenient and high-efficiency test kit for detecting CN − by naked eyes in the actual sample.

Azole and Azine Derivatives Containing (η6-Arene)tricarbonylchromium Substituents

Azole and Azine Derivatives Containing (η6-Arene)tricarbonylchromium Substituents

Substitution dependent multi-color AIE behavior and ESIPT active A-D-A type triphenylamine supported bis unsymmetrical azine derivatives and their antibacterial activity

A facile synthetic approach afforded a new family of AIE active and ESIPT featured A-D-A (Acceptor-Donor-Acceptor) type symmetrical triphenylamine centered bis unsymmetrical azine derivatives TPSA, TPHY, TPDS and TPOV. Depending upon the substituent in the periphery, all compounds displayed frail fluorescence in the solution state and exhibited strong multi-color luminescence character in aggregated/solid state. The results achieved from UV–visible absorption, emission and theoretical studies confirmed the existence of the intramolecular proton transfer phenomenon in the excited state (ESIPT). The experimental results affirmed AIE behavior present in the compounds and it might be due to the restriction of the intramolecular rotation (RIR) mechanism. The in vitro antibacterial activity of the compounds was also scrutinized against elected bacterial strains (B. subtilis, S. aureus, E. coli, and P. aeruginosa) in different concentrations (0.5 mM, 1 mM, 1.5 mM). The results revealed that all four compounds have excellent antibacterial activity at 1.5 mM than other concentrations tested in the present study. Further, the fluorescence feature of the compounds was explored via fluorescence microscopy to probe the microbes (Pseudomonas aeruginosa).

Synthesis, Antimicrobial Evaluation, and Molecular Docking of New Azole, Azine, Thiazole, and Chromene Derivatives

Novel heterocyclic compounds containing a benzothiazole moiety (2–16) were synthesized via the reaction of benzothiazole cyanoacetamide derivative (2) with different types of reagents. All compounds were characterized by 1H NMR, MS, and IR techniques. The newly synthesized compounds were examined for their in vitro antibacterial activity against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and fungi (Candida albicans) microorganisms. Compounds (5, 6, 7, and 15) are promising antimicrobial agents and could be the lead compounds for more potent drugs. Binding modes of the synthesized compounds were analyzed by docking studies that showed good binding scores against the diverse amino acids of the two selected proteins (PDB Codes – 2EXB and 3HUN). The conducted docking studies were found to be consistent with antimicrobial results. Thus, the results indicate that the designed structures can be a potential lead as antimicrobial agents.

Synthesis, Anti‐migration and Catalytic Effect of Ferrocene Azine Derivatives on the Thermal Decomposition of Ammonia Perchlorate

AbstractFerrocene burning rate catalyst (BRC) is a common catalyst to promote the combustion of composite solid propellant because of its high catalytic performance, but this kind of catalyst has the disadvantage of easy migration. Ammonia perchlorate (AP) is the main oxidant of composite solid propellant, and its thermal degradation behavior has an important impact on the combustion of propellant. New mononuclear and polynuclear ferroceneazine BRCs were synthesized, and their structures were characterized by UV‐Vis, NMR, HRMS and IR spectra. The catalytic effects of these ferrocenylazines on the thermal degradation of AP were studied by DSC and TG. The results confirmed that the catalytic performance of azine without bisferrocenylpropane was inferior to that of Catocene (Cat), while the catalytic performance of azine with bisferrocenylpropane was equivalent to that of Cat. Anti‐migration studies showed that both mononuclear ferroceneazines and Cat showed mobility, while polynuclear ferroceneazines did not migrate after long‐term storage. Therefore, polynuclear ferroceneazine is a new kind of high‐efficiency and non‐migration BRC with application prospects.

Novel High Sensitivity Dual-Channel Chemosensor for Detecting Cn− Based on Asymmetric Azine Derivatives in Aqueous Media

Novel High Sensitivity Dual-Channel Chemosensor for Detecting Cn− Based on Asymmetric Azine Derivatives in Aqueous Media

11H-Indeno[1,2-b]quinoxalin-11-one 2-(4-ethylbenzylidene)hydrazone

11H-Indeno[1,2-b]quinoxaline derivatives present an important type of nitrogen-containing heterocyclic compound that are useful intermediate products in organic synthesis and have potential pharmaceutical applications. A new 11H-indeno[1,2-b]quinoxalin-11-one-2-(4-ethylbenzylidene)hydrazone (compound 3) was synthesized. Compound 3 is the first example of an azine derivative based on the 11H-indeno[1,2-b]quinoxaline system. The Z,E-isomerism of compound 3 was investigated by DFT calculations. Bioavailability was evaluated in silico using ADME predictions. According to the ADME results, compound 3 is potentially highly bioavailable and has potential to be used for the treatment of neuroinflammation and ischemia–reperfusion injury.

Synthesis of Symmetrical Acetophenone Azine Derivatives as Colorimetric and Fluorescent Cyanide Chemosensors

Cyanide is a highly toxic anion and poison to the environment. Therefore, fast, effective, and efficient analysis methods to detect cyanide are needed. Herein, symmetrical chemosensor of 2’-hydroxy acetophenone azine (1) and 2’,4’-dihydroxy acetophenone azine (2) has been synthesized tested as colorimetric and fluorescent cyanide chemosensor. The azines were produced from the condensation of acetophenone derivatives with hydrazine hydrate in ethanol under reflux or ultrasonic irradiation methods. Colorimetric and fluorescent chemosensor tests showed selectivity to acetate and cyanide anions in DMSO. The limit of detection (LOD) for colorimetric measurement of cyanide anion was 9.68×10–4 M for compound (1) and 9.63×10–5 M for compound (2), while the fluorescent method showed 15.90×10–4 M for compound (1) and 8.95×10–5 M for compound (2), respectively. In addition, test paper-strips containing sensor 2 indicated noticeable results for 'naked eye' detection of cyanide in an aqueous medium.

Design, synthesis, and biological evaluation of symmetrical azine derivatives as novel tyrosinase inhibitors

A series of symmetrical azine derivatives containing different substituted benzyl moieties were designed, synthesized, and evaluated for their inhibitory activity against tyrosinase. The results showed that compounds 3e, 3f, 3h, 3i, 3j, and 3k possess effective tyrosinase inhibition with IC50 values ranging from 7.30 μM to 62.60 μM. Particularly, compounds 3f displayed around three-fold improvement in the potency (IC50 = 7.30 ± 1.15 μM) compared to that of kojic acid (IC50 = 20.24 ± 2.28 μM) as the positive control. Kinetic study of compound 3f confirmed uncompetitive inhibitory activity towards tyrosinase indicating that it can bind to enzyme–substrate complex. Next, molecular docking analysis was performed to study the interactions and binding mode of the most potent compound 3f in the tyrosinase active site. Besides, the cytotoxicity of 3f, as well as its potency to reduce the melanin content were also measured on invasive melanoma B16F10 cell line. Also, 3f exhibited above 82% cell viability in the A375 cell line at 10 µM. Consequently, compounds 3f could be introduced as a potent tyrosinase inhibitor that might be a promising candidate in the cosmetics, medicine, and food industry.

Synthesis and physical studies of coumarin-based chemosensor for cyanide ions

A series of novel coumarin-based chemosensor azine derivatives L1, L2 and L3 were synthesized and characterized by various spectroscopic methods such as 1H NMR, mass spectrometry, FT-IR and elemental analysis. The sensing property of the sensor L derivatives was confirmed by the UV–Vis absorption, emission spectra and the naked eye sensing. The sensor L derivatives showed the absorption band at 320–330 nm. The fluorescence emission band was observed at 550–560 nm. In the presence of CN− ions, the chemosensor L derivatives show the “turn-on” fluorescence response over the other competing anions such as Br−, I−, HSO4−, ClO4− and PF6−, and the new absorption band appeared at 385 nm and the emission band also shifted to the blue region at 440 nm. The sensor L derivatives bind to cyanide ions in a 1:1 binding stoichiometry calculated from the job’s plot experiments. The detection limit of sensor L1 towards CN− was 5.79 × 10−8 M. Additionally, the binding constant was determined to be 1.0209 × 106 M−1 from the Benesi-Heilbrand equation. The theoretical calculations were performed by Gaussian 9 software. The sensing mechanism of the interaction between the cyanide ion and imine carbon was confirmed by the 1H NMR titration method and mass spectra.