Imidazoline Derivatives Research Articles

Exploring the antimicrobial potential of novel 2-oxo-2-H-chromene conjugates with guanine, thiazole, and imidazole: Synthesis, characterization, and biological evaluation

Five derived forms of 2-oxo-2-H-chromene clubbed guanine, thiazole and imidazoline derivatives 10 (i–v), 11 (i–v), and 12 (i–v) were synthesized, characterized, and biologically tested for in vitro antimicrobial activity against two types of bacteria viz. Staphylococcus aureus (MTCC 87) and Escherichia coli (MTCC 40). The synthesized compounds demonstrated mild to moderate antibacterial activity against Escherichia coli and Staphylococcus aureus at all concentrations (100 μg/ml, 250 μg/ml, and 500 μg/ml) in comparison to standard drug ciprofloxacin. It was observed that the compounds 10i, 10v, 11i, 11v, 12i, 12ii, 12iv and 12v have noticeable activity at higher dose in comparison to standard drug. Zone of inhibition values indicated higher antimicrobial activity at 500 μg/ml against Escherichia coli and Staphylococcus aureus in case of imidazoline and thiazole clubbed coumarin derivatives in comparison to guanine derivatives. The guanine derivatives have been found to be potent at lower dose (100 μg/ml) in comparison to thiazole and imidazoline derivatives having negligible activity at 100 μg/ml. This suggests a differential efficacy profile among the synthesized compounds, with guanine derivatives showing promising activity at lower doses while thiazole and imidazole derivatives manifesting increased potency at higher concentrations. These findings underscore the potential of these novel compounds as antimicrobial agents, warranting further investigation into their mechanisms of action and therapeutic applications.

Penetration of imidazoline derivatives through deposited scale for inhibiting the under-deposit corrosion of pipeline steel

Effective penetration of corrosion inhibitors through deposits is vital for controlling under-deposit corrosion (UDC) in oil/gas production. Herein, the penetration of three imidazoline derivatives across a CaCO3-based scale in CO2-saturated brine was examined, along with the resulting protection effect on mild steel. Real-time spectral monitoring revealed the correlation between inhibitor structures and penetration ability, with a maximum permeability of 24.1 %. Imidazoline's affinity with water, indicated by coordination number, significantly influenced the penetration. The intrinsic efficacy of imidazoline derivatives determined actual UDC inhibition efficiency, reaching a maximum of 92.33 %, under conditions of sufficient penetration.

Biological impacts of imidazoline derivatives

Biological impacts of imidazoline derivatives

Narrow bandgap Sn-Pb perovskite solar cells with high operational stability modulated by imidazoline derivative

Sn-Pb mixed perovskites with narrow bandgap (NBG) are important for high-performance single- and multi-junction perovskite solar cells (PSCs). However, the inherent Sn2+ oxidation and ion migration lead to inferior stability. Herein, 2-hydrazino-2-imidazoline hydrobromide (2H2I) is employed as a coordinating additive to regulate the film crystallization and inhibit Sn2+ oxidation. Meanwhile, 2H2I can form hydrogen bonds with I− ions to suppress ion migration, thereby improving photovoltaic stability. The target FA0.8Cs0.2Sn0.5Pb0.5I3:2H2I PSC exhibits a champion power conversion efficiency (PCE) of 22.44 %, higher than that of the control device (19.16 %). The target devices retain 90 % (T90) and 80 % (T80) of the initial PCE under maximum power point (MPP) tracking for 1360 h at room temperature and for 436 h at 65 °C, respectively, the highest values for NBG Sn-Pb PSCs. This work demonstrates an effective strategy toward photothermally stable Sn-Pb PSCs.

Synergistic effect of new imidazoline derivative and 2‐aminopyridine as corrosion inhibitors for Q235: Experimental and theoretical study

In order to reduce the investment of corrosion inhibitors, based on experimental and theoretical studies, the corrosion inhibition and mechanism of new imidazoline derivatives (SMIS) and 2‐aminopyridine (AMP) were investigated carefully. The best corrosion inhibition effect was at 0.7‐g/L SMIS and 0.3‐g/L AMP, the corrosion inhibition efficiency of weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization (Tafel) were 90.54%, 98.56% and 97.68%, respectively. Electrochemical research shows that SMIS&AMP belongs to cathodic corrosion inhibition. SMIS&AMP mainly increased the film resistance and charge transfer resistance in 1‐M HCl, thus playing a certain role in corrosion inhibition. X‐ray photoelectron spectroscopy and energy dispersive spectrometer proved that SMIS&AMP can be adsorbed on the surface of Q235, molecular dynamics showed that there was a certain synergy between SMIS and AMP. This study confirmed that SMIS and AMP have a good synergistic effect, improve the corrosion inhibition efficiency, reduce the synthesis cost of SMIS, and have a certain guiding significance for synergistic corrosion inhibition.

Green and rapid and instrumental one-pot method for the synthesis of imidazolines having potential anti-SARS-CoV-2 main protease activity

The Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) is responsible for ongoing epidemics in humans and some other mammals and has been declared a public health emergency of international concern. In this project, several small non-peptide molecules were synthesized to inhibit the major proteinase (Mpro) of SARS-CoV-2 using rational strategies of drug design and medicinal chemistry. Mpro is a key enzyme of coronaviruses and plays an essential role in mediating viral replication and transcription in human lung epithelial and stem cells, making it an attractive drug target for SARS-CoV. The antiviral potential of imidazoline derivatives as inhibitors of (SARS-CoV-2) Mpro was evaluated using in-silico techniques such as molecular docking simulation, molecular dynamics (MD), and ADMET prediction. The docking scores of these imidazoline derivatives were compared to that of the N3 crystal inhibitor and showed that most of these compounds, particularly compound E07, interacted satisfactorily in the active site of the coronavirus and strongly interacted with the residues (Met 165, Gln 166, Met 165, His 41, and Gln 189). Furthermore, the results were confirmed by MD simulations after exposure to long-term MD simulations and ADMET predictions.

Synthesis of Some Nucleoside Analogs via Mannich Reaction of Benzimidazole and Imidazoline Derivatives and Their Characterization as Potential Antimicrobial Agents

Synthesis of Some Nucleoside Analogs via Mannich Reaction of Benzimidazole and Imidazoline Derivatives and Their Characterization as Potential Antimicrobial Agents

Electrochemical and molecular modelling studies of corrosion inhibition characteristics of imidazolines on 1Cr steel under sweet conditions

ABSTRACT Organic compounds like imidazoline derivatives are commonly used as corrosion inhibitors. This study characterised the corrosion inhibition properties of two forms of imidazoline, 2-Methyl-2-imidazoline (2-MI) and 2-Phenyl-2-imidazoline (2-PI), with and without the presence of mono ethylene glycol (MEG) on steel surface under CO2 corrosion condition. Electrochemical, surface characterisation and molecular modelling were used to study corrosion inhibition properties and underlying mechanisms. In the pure form, 2-PI had higher corrosion inhibition efficiency than 2-MI, likely due to stronger adsorption to the steel surface, as confirmed by molecular modelling. The addition of MEG improved the inhibitor efficiency of both 2-MI and 2-PI.

Corrosion inhibition by imidazoline and imidazoline derivatives: a review

Abstract Imidazoline and imidazoline derivatives are extensively employed as effective corrosion inhibitors due to their low toxicity, low cost and environmental friendliness. Their chemical structure consists of a 5-membered heterocyclic ring (C3N2H4) with two nitrogen atoms that are readily adsorbed onto metal surfaces. Also, a pendant side chain or alkyl amine substituent acts as an anchor that helps to maintain its adsorption on steel surfaces. The tail portion is a long hydrocarbon chain that can form a hydrophobic film on a surface. These molecular structures make it very attractive as a starting point for several enhancements in corrosion inhibition research. Moreover, modification of an imidazoline structure can be more effective in enhancing its effectiveness in corrosion inhibition. This review compiled all information regarding imidazoline and imidazoline derivatives used as effective corrosion inhibitors in the petroleum industry. It includes their chemical structures and properties, synthesis processes, characterisation and performance evaluations. The review also gives an overview of various types of imidazoline inhibitors with their preparation processes, metal types, corrosive media and concentration range for measurements.

Fluorocarbon chain-based imidazoline derivatives as highly efficient corrosion inhibitors at elevated temperatures

In this paper, two imidazoline derivatives, N1-(2-aminoethyl)-N2-(2-((2-(2-heptyl-4,5-dihydro-1H-imidazol-1-yl)ethyl)amino)ethyl)ethane-1,2-diamine (HEIM) and N1-(2-aminoethyl)-N2-(2-((2-(2-(perfluoroheptyl)-4,5-dihydro-1H-imidazol-1-yl)ethyl)amino)ethyl)ethane-1,2-diamine (PFIM), have been used as corrosion inhibitors of carbon steels in 1 M HCl at elevated temperatures. Two inhibitors are confirmed by 1H NMR, 13C NMR, high-resolution mass spectra and FT-IR tools. Electrochemical and immersion tests indicate that the PFIM displays a stable protection performance at different temperatures, with an inhibition efficiency value around 95%. Moreover, scanning Electron Microscopy (SEM), energy dispersive X-ray (EDX) analysis, atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) indicates that the PFIM inhibitor film shows high hydrophobicity and stability at 363 K. Theoretical calculations suggest that the adsorption of PFIM is mainly through the bonding of the F of fluorocarbon chain on the Fe surface. This study helps us further explore the inhibition mechanisms of fluorocarbon chain-based imidazoline derivatives at high temperatures.

Preparations methods of tizanidine (API) and related compounds: A review

Tizanidine is an imidazoline derivative with the agonistic activity of central alpha 2 receptors at both the spinal and supra-spinal levels. It was prepared for the first time in 1978 and approved for use in 1996. The present review focuses on all methods used for the synthesis of tizanidine, related compounds and intermediates. This review article covers all the methods that have been used in the preparation of tizanidine since its discovery until now. Methods used for the preparation of tizanidine-related compounds are also covered. This review gives those interested in drug synthesis and designs the ability to form a complete picture of the preparation of this drug, as well as providing the opportunity for the synthesis of other drugs developed from this drug to increase activity and/or reduce side effects.

Amidinoquinoxaline N-oxides: synthesis and activity against anaerobic bacteria.

We present herein an in-depth study on the activity of amidinoquinoxaline N-oxides 1 against Gram-positive and Gram-negative anaerobic bacteria. Based on 5-phenyl-2,3-dihydropyrimidoquinoxaline N-oxide 1a, the selected structural variations included in our study comprise the substituents α- to the N-oxide function, the benzofused ring, substitution and quaternization of the amidine moiety, and the amidine ring size. Compounds 1 showed good to excellent antianaerobic activity, evaluated as the corresponding CIM50 and CIM90 values, and an antimicrobial spectrum similar to metronidazole. Six out of 13 compounds 1 had CIM90 values significantly lower than the reference drug. Among them, imidazoline derivatives 1i-l were the most active structures. Such compounds were synthesized by base-promoted ring closure of the corresponding amidines. The N-oxides under study showed no significant cytotoxicity against RAW 264.7 cells, with high selectivity indexes. Their calculated ADME properties indicate that the compounds are potentially good oral drug candidates. The antianaerobic activity correlated satisfactorily with the electron affinity of the compounds, suggesting that they may undergo bioreductive activation before exerting their antibacterial activity.

Synthesis of Fatty Imidazoline from Oleic Acid with Ethylenediamine and its Characterization

In this work, imidazoline-oleic derivative had been successfully synthesized by reacting ethylenediamine (EDA) with oleic acid (OA). The synthesis process was performed with MAOS (Microwave Assisted Organic Synthesis) and the conventional method (reflux with Dean-Stark) using xylene as a solvent was also performed as comparisons. The percentage yield of EDA-OA imidazoline was obtained from Reflux with Dean-Stark at 5 hours (90 %), and MAOS at 10 min (68,2 %). EDA-OA imidazoline then was identified by using thin-layer chromatography, and the separation method by KVC with eluent CHCl3: MeOH (9:1) with ammonium solution followed by characterization using Fourier Transform Infrared (FTIR), UV-Vis, Proton Nuclear Magnetic Resonance (1H-NMR). This study provides information regarding the comparison method for imidazoline derivative synthesis. For further research, EDA-OA imidazoline can be used as a corrosion inhibitor towards carbon steel.

2-Imidazoline Nitroxide Derivatives of Cymantrene.

The 2-imidazoline nitroxide derivatives of cymantrene-2-(η5-cyclopentadienyl)tricarbonylmanganese(I)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (NNMn) and 2-(η5-cyclopentadienyl)tricarbonylmanganese(I)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl (INMn) were synthesized. It was shown that NNMn and INMn exhibit a sufficiently high kinetic stability both in solids and in solutions under normal conditions. Their structural characteristics, magnetic properties and electrochemical behavior are close to Re(I) analogs. This opens the prospect of using paramagnetic cymantrenes as prototypes in the design of Re(I) half-sandwiched derivatives for theranostics, where therapy is combined with diagnostics by magnetic resonance imaging due to the contrast properties of nitroxide radicals.

Corrosion inhibition behavior of X80 pipeline steel by imidazoline derivative in the CO2-saturated seawater containing sulfate-reducing bacteria with organic carbon starvation

In this work, corrosion inhibition of steel caused by imidazoline derivative in the presence of sulfate-reducing bacteria (SRB) with organic carbon starvation was investigated in CO2-saturated seawater. Results demonstrate that the corrosion is inhibited by SRB with a high initial count in the absence of organic carbon but it is accelerated when the initial SRB counts decrease. The maximum value of corrosion rate caused by SRB is (0.179 ± 0.003) mm/y. The inhibition efficiency of imidazoline derivative is improved with a value of 76.2% after 14 days of testing when the initial SRB is 107 cells/mL.

Effect of imidazoline derivatives on the corrosion inhibition of Q235 steel in HCl medium: experimental and theoretical investigation

Abstract In this work, two new imidazoline derivatives (SMF and SMIF) have been synthesized successfully, and their structure have been confirmed by IR, Raman, and NMR techniques. The corrosion inhibition ability and mechanism in HCl solution were proved by experimental and theoretical methods. The inhibition efficiency of SMIF was 94.69% in weight loss experiment, 95.99% (Tafel), and 95.30% (EIS) in electrochemistry. The corrosion inhibition mechanism is that SMF and SMIF form a stable protective film on the surface of Q235 and hinders charge transfer. EDS, FT-IR, and XPS all proved that SMF and SMIF inhibitors could stably adsorb on Q235 surface and form a protective film. The DFT and MD also proved the corrosion inhibiton mechanism. Experiments and theoretical calculations showed that SMF and SMIF exhibited excellent corrosion inhibition performance in 1 M HCl solution.

Experimental and Theoretical Studies on the Inhibition Properties of an Imidazoline Derivative on Q235 Corrosion in a Simulated Concrete Pore Solution

AbstractA novel imidazoline derivative has been synthesized and its molecular structure has been confirmed by IR, Raman, elemental analysis and NMR, the molecular structure of the inhibitor is similar to that of the previous research. In this paper, the inhibition performance and inhibition mechanism of the three inhibitors (SMID, SMIS and SMIF) in concrete simulation solution are analyzed and compared. The corrosion inhibition efficiency of SMIF (96.02 %) > SMIS (93.62 %)>SMID(93.01 %) in weight loss experiment, the SMIS of electrochemistry of Nyquist and potentiodynamic polarization were 89.72 % and 92.03 % respectively, which indicated that SMIS had good corrosion inhibition effect. Electrochemical experiments show that the SMIS belongs to anodic type, and the mechanism of SMIS can form a protective film on the surface Q235 and inhibit the charge transfer. The results of FTIR, EDS and XPS show that SMIS can be adsorbed on the surface of Q235, which is also confirmed by density functional theory (DFT) and molecular dynamics simulation (MD).

Structural insights into ligand recognition, activation, and signaling of the α2A adrenergic receptor.

The α2A adrenergic receptor (α2AAR) is a G protein (heterotrimeric guanine nucleotide–binding protein)–coupled receptor that mediates important physiological functions in response to the endogenous neurotransmitters norepinephrine and epinephrine, as well as numerous chemically distinct drugs. However, the molecular mechanisms of drug actions remain poorly understood. Here, we report the cryo–electron microscopy structures of the human α2AAR-GoA complex bound to norepinephrine and three imidazoline derivatives (brimonidine, dexmedetomidine, and oxymetazoline). Together with mutagenesis and functional data, these structures provide important insights into the molecular basis of ligand recognition, activation, and signaling at the α2AAR. Further structural analyses uncover different molecular determinants between α2AAR and βARs for recognition of norepinephrine and key regions that determine the G protein coupling selectivity. Overall, our studies provide a framework for understanding the signal transduction of the adrenergic system at the atomic level, which will facilitate rational structure-based discovery of safer and more effective medications for α2AAR.

Synergistic Effect of Imidazoline Derivative and Benzimidazole as Corrosion Inhibitors for Q235 Steel: An Electrochemical, XPS, FT-IR and MD Study

Synergistic Effect of Imidazoline Derivative and Benzimidazole as Corrosion Inhibitors for Q235 Steel: An Electrochemical, XPS, FT-IR and MD Study

Ring opening and skeletal reconstruction of 3-vinyl benzofuranone-chromone synthons: catalyst-free access to skeletally-diverse 2-pyridone and optically active imidazoline derivatives.

Herein is reported the first example of ring opening and skeletal reconstruction of 3-vinyl benzofuranone-chromones 1 as versatile synthons, which can react with ammonia or primary aliphatic amines as binucleophiles, for the eco-friendly and atom-economical synthesis of diverse and functionalized 2-pyridones 3 with potential biological activity in good to excellent yields (77-93%). When using optically active 1,2-diphenylethylenediamine 2 as the binucleophile, the in situ generated 2-pyridone intermediates are successfully transformed to novel optically active functionalized imidazoline derivatives 4 with high efficiency (up to 87% yield). In particular, this is the first report on the catalyst-free intramolecular cyclization occurring between an amide and a primary aliphatic amine for the construction of imidazoline molecules.