Zolpidem: a review of its use in the management of insomnia

Medical management for cerebellar mutism syndrome following posterior fossa surgery: A systematic review

INTRODUCTION

Cerebellar mutism syndrome (CMS) is a serious complication of posterior fossa surgeries affecting mainly pediatric age group. The pathophysiology is still not fully understood. It adversely affects the recovery of patients. There is no definitive and standardized management for CMS. However pharmacological therapy has been used in reported cases with variable effectiveness. We aim through this review to summarize the available evidence on pharmacological agents used to treat CMS.

METHOD

A thorough systematic review until December 2022, was conducted using PubMed Central, Embase, and Web of Science, databases to identify case reports and case series of CMS patients who underwent posterior fossa surgery and received pharmacological treatment. Patients with pathologies other than posterior fossa lesions were excluded from the study.

RESULTS

Of 592 initial studies, 8 studies met our eligibility criteria for inclusion, with 3 more studies were added through manual search; reporting on 13 patients. The median age of 13 years (Standard deviation SD=10.60). The most frequent agent used was Bromocriptine. Other agents were fluoxetine, midazolam, zolpidem, and arpiprazole. Most patients recovered within 48 hours of initiating medical therapy. The median follow-up period was 4 months (SD=13.8). All patients showed complete recovery at the end of follow-up period.

CONCLUSION

Cerebellar mutism syndrome is reported after posterior fossa surgeries, despite attempts to identify risk factors, pathophysiology, and management of CMS, it remains a challenging condition with significant morbidity. Different Pharmacological treatments have been proposed with promising results. Further studies and formalized clinical trials are needed to evaluate available options and their effectiveness.

Imidazo[1,2-a]pyridine and Imidazo[1,5-a]pyridine: Electron Donor Groups in the Design of D-π-A Dyes

This work investigates the electron-donating capabilities of two 10-π electron nitrogen bridgehead bicyclic [5,6]-fused ring systems, imidazo[1,2-a]pyridine and imidazo[1,5-a]pyridine rings. Eight compounds with varying positions of electron-withdrawing moieties (TCF or DCI) coupled to the imidazopyridine ring were synthesized and studied. DCI-containing compounds (Ib-IVb) exhibited a purely dipolar nature with broad absorption bands, weak fluorescence, large Stokes shifts, and strong solvatochromism. In contrast, TCF-containing compounds (Ia-IVa) demonstrated diverse properties. Imidazo[1,2-a]pyridine derivatives Ia and IIa were purely dipolar, while imidazo[1,5-a]pyridine derivatives IIIa and IVa displayed a cyanine-like character with intense absorption and higher quantum yields of emission. The observed gradual red shift in optical properties with changing electron-donor groups (IIb < Ib < IIIb < IVb) and (IIa < Ia < IIIa < IVa) underscores the stronger electron-donor character of imidazo[1,5-a]pyridine compared to that of imidazo[1,2-a]pyridine. Furthermore, crystalline powders of imidazo[1,2-a]pyridine derivatives exhibited fluorescence despite minimal emission in solution. Two compounds (Ib and IVa) were successfully formulated into nanoparticles for potential in vivo imaging applications in zebrafish embryos.

Design and synthesis of imidazo[1,2-a]pyridine-chalcone conjugates as antikinetoplastid agents

A library of imidazo[1,2-a]pyridine-appended chalcones were synthesized and characterized using 1 H NMR, 13 C NMR and HRMS. The synthesized analogues were screened for their antikinetoplastid activity against Trypanosoma cruzi, Trypanosoma brucei brucei, Trypanosoma brucei rhodesiense and Leishmania infantum. The analogues were also tested for their cytotoxicity activity against human lung fibroblasts and primary mouse macrophages. Among all screened derivatives, 7f was found to be the most active against T. cruzi and T. b. brucei exhibiting IC50 values of 8.5 and 1.35 μM, respectively. Against T. b. rhodesiense, 7e was found to be the most active with an IC50 value of 1.13 μM. All synthesized active analogues were found to be non-cytotoxic against MRC-5 and PMM with selectivity indices of up to more than 50.

Synthesis of Imidazo[1,2-a]pyridine-Fused 1,3-Benzodiazepine Derivatives with Anticancer Activity via a One-Pot Cascade GBB-3CR/Pd(II)-Catalyzed Azide-Isocyanide Coupling/Cyclization Process

A new one-pot synthesis of imidazo[1,2-a]pyridine-fused 1,3-benzodiazepine derivatives via a sequential GBB-3CR/Pd(II)-catalyzed azide-isocyanide coupling/cyclization process was developed. The Groebke-Blackburn-Bienaymé three-component reactions (GBB-3CR) of 2-aminopyridine, 2-azidobenzaldehydes, and isocyanides in the presence of a catalytic amount of p-toluenesulfonic acid gave azide intermediates without separation. The reaction was followed by using another molecule of isocyanides to produce imidazo[1,2-a]pyridine-fused 1,3-benzodiazepine derivatives in good yields by the Pd(II)-catalyzed azide-isocyanide coupling/cyclization reaction. The synthetic approach produces novel nitrogen-fused polycyclic heterocycles under mild reaction conditions. The preliminary biological evaluation demonstrated that compound 6a inhibited glioma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.

Speedy Gonzales analysis method in one drop of beverage, for crimes committed with drugs from three different groups

Sertraline, zolpidem and fentanyl, are drugs with potential to be used in cases of rape, property theft and organ theft. In this study, a 15 min dilute-and-shoot analysis method was developed for the simultaneous confirmation and quantification of these drugs, using liquid chromatography tandem mass spectrometry (LC-MS/MS), in the residues of fruit juice types (mixed fruit juice, cherry juice and apricot juice), frequently consumed soft drinks. A C₁₈ phenomenex column (3 µm × 100 mm × 3 mm) was used in LC-MS/MS analysis. Validation parameters were determined by means of linearity, linear range, LOD, LOQ, repeatability and intermediate precision studies. The linearity of the method was shown up to 2.0 μgmL^-1 concentration and r² was ≥ 0.99, for each analyte. LOD and LOQ values were found in the ranges of 4.9-10.2 and 13.0-57.5 ngmL^-1 for all the analytes. Accuracies were between 74 and 126%. HorRat values calculated (between 0.57 and 0.97), revealed that the inter-day precisions (RSD% ≤ 15.5%) are acceptable. The simultaneous extraction and determination of these analytes in beverage residues in very low amounts as 100 µL is challenging because of the difficulty arising from the different chemical properties, the complexity of mixed fruit juice matrix. The method is important for hospitals (especially in emergency-toxicology cases), criminal and special laboratories from the point of determining the combined or single use of these drugs in drug facilitated crimes (DFC) and finding out the reasons of deaths related to these drugs.

Arousal Regulation by the External Globus Pallidus: A New Node for the Mesocircuit Hypothesis

In the decade since its debut, the Mesocircuit Hypothesis (MH) has provided researchers a scaffolding for interpreting their findings by associating subcortical-cortical dysfunction with the loss and recovery of consciousness following severe brain injury. Here, we leverage new findings from human and rodent lesions, as well as chemo/optogenetic, tractography, and stimulation studies to propose the external segment of the globus pallidus (GPe) as an additional node in the MH, in hopes of increasing its explanatory power. Specifically, we discuss the anatomical and molecular mechanisms involving the GPe in sleep-wake control and propose a plausible mechanistic model explaining how the GPe can modulate cortical activity through its direct connections with the prefrontal cortex and thalamic reticular nucleus to initiate and maintain sleep. The inclusion of the GPe in the arousal circuitry has implications for understanding a range of phenomena, such as the effects of the adenosine (A2A) and dopamine (D2) receptors on sleep-wake cycles, the paradoxical effects of zolpidem in disorders of consciousness, and sleep disturbances in conditions such as Parkinson's Disease.

Synthesis of Tunable Fluorescent Imidazole-Fused Heterocycle Dimers

A short, concise, and one-pot synthesis of imidazo-fused heterocycle dimers with tunable fluorescent properties has been developed. By the first time use of glyoxal dimethyl acetal in the Groebke–Blackburn–Bienaymé (GBB) three-component reaction (3CR), the innovation features a new series of fluorescence-tunable imidazo-fused heterocycle dimers exhibiting a broad substrate scope with good yields. Luminescence studies demonstrate that these GBB-dimers possess color-tunable properties, and their emission colors can be successively changed from blue to green and yellow by easy substituent control.

Crystal structure and Hirshfeld surface analysis of 2-oxo-2-phenylethyl 3-nitroso-2-phenylimidazo[1,2-a]pyridine-8-carboxylate

In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, generating (5) and (28) ring motifs. In addition, weak C—H⋯π and π-stacking inter­actions are observed.

The title compound, C₂₂H₁₅N₃O₄, is built up from a central imidazo[1,2-a]pyridine ring system connected to a nitroso group, a phenyl ring and a 2-oxo-2-phenyl­ethyl acetate group. The imidazo[1,2-a] pyridine ring system is almost planar (r.m.s. deviation = 0.017 Å) and forms dihedral angles of 22.74 (5) and 45.37 (5)°, respectively, with the phenyl ring and the 2-oxo-2-phenyl­ethyl acetate group. In the crystal, the mol­ecules are linked into chains parallel to the b axis by C—H⋯O hydrogen bonds, generating R₂¹ (5) and R₄⁴ (28) graph-set motifs. The chains are further linked into a three-dimensional network by C—H⋯π and π-stacking inter­actions. The inter­molecular inter­actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (36.2%), H⋯C/C⋯H (20.5%), H⋯O/O⋯H (20.0%), C⋯O/O⋯C (6.5%), C⋯N/N⋯C (6.2%), H⋯N/N⋯H (4.5%) and C⋯C (4.3%) inter­actions.

The top 100 most cited papers in insomnia: A bibliometric analysis

OBJECTIVE

The number of citations to a paper represents the weight of that work in a particular area of interest. Several highly cited papers are listed in the bibliometric analysis. This study aimed to identify and analyze the 100 most cited papers in insomnia research that might appeal to researchers and clinicians.

METHODS

We reviewed the Web of Science (WOS) Core Collection database to identify articles from 1985 to 24 March 2022. The R bibliometric package was used to further analyze citation counts, authors, year of publication, source journal, geographical origin, subject, article type, and level of evidence. Word co-occurrence in 100 articles was visualized using VOS viewer software.

RESULTS

A total of 44,654 manuscripts were searched on the Web of Science. Between 2001 and 2021, the top 100 influential manuscripts were published, with a total citation frequency of 38,463. The top countries and institutions contributing to the field were the U.S. and Duke University. Morin C.M. was the most productive author, ranking first in citations. Sleep had the highest number of manuscripts published in the top 100 (n = 31), followed by Sleep Medicine Reviews (n = 9). The most cited manuscript (Bastien et al., Sleep Medicine, 2001; 3,384 citations) reported clinical validation of the Insomnia Severity Index (ISI) as a brief screening indicator for insomnia and as an outcome indicator for treatment studies. Co-occurrence analyses suggest that psychiatric disorders combined with insomnia and cognitive behavioral therapy remain future research trends.

CONCLUSION

This study provides a detailed list of the most cited articles on insomnia. The analysis provides researchers and clinicians with a detailed overview of the most cited papers on insomnia over the past two decades. Notably, COVID-19, anxiety, depression, CBT, and sleep microstructure are potential areas of focus for future research.

One-Pot Synthesis of 3-Methyl-2-arylimidazo[1,2-a]pyridines Using Calcium Carbide as an Alkyne Source

An efficient method for the construction of 3-methyl-2-arylimidazo[1,2-a]pyridines from the reactions of calcium carbide, 2-aminopyridines, and aromatic aldehydes is described. The notable advantages for this strategy include the use of an inexpensive and concise solid alkyne source, cheap and readily available raw materials, wide-scope substrates, and a simple work-up procedure.

Electrochemical sulfonylation of imidazoheterocycles under batch and continuous flow conditions

An efficient and versatile protocol for the C-H sulfonylation of imidazoheterocycles via electrochemical activation was established under batch and flow conditions. The selective C-H bond functionalization proceeded under catalyst- and oxidant-free conditions and tolerated a wide range of functional groups. Various sodium sulfinates as well as imidazo[1,2-a]-pyridines, -pyrimidine, -quinolines, and -isoquinolines, imidazo[1,2-b]pyridazine, imidazo[2,1-b]thiazoles and benzo[d]imidazo[1,2-b]thiazoles reacted successfully. Interestingly, significant acceleration and higher yields were obtained under microfluidic conditions.

Gold-catalyzed oxidation of terminal alkynes to glyoxals and their reactions with 2-phenylimidazo[1,2-a]pyridines: one-pot synthesis of 1,2-diones

A novel one-pot protocol for the convenient and efficient synthesis of (2-phenylimidazo[1,2-a]pyridin-3-yl)alkane-1,2-diones (3) in good yields (32-88%) from 2-phenylimidazo[1,2-a]pyridines (1) and terminal alkynes (2) has been established with a wide range of substrate scope. A tandem reaction sequence containing gold-catalyzed double oxidations of terminal alkynes to generate glyoxals, nucleophilic addition of 2-phenylimidazo[1,2-a]pyridines to glyoxals to yield α-hydroxyl ketones, and oxygenation of the α-hydroxyl ketones to afford the final products 3 under air atmosphere is involved in this method. Simple operation, mild reaction conditions, and widely available substrates make this strategy more affordable.

KIO4 -mediated Selective Hydroxymethylation/Methylenation of Imidazo-Heteroarenes: A Greener Approach

Herein, we report a KIO₄ -mediated, sustainable and chemoselective approach for the one-pot C(sp² )-H bond hydroxymethylation or methylenation of imidazo-heteroarenes with formaldehyde, generated in situ via the oxidative cleavage of ethylene glycol or glycerol (renewable reagents) through the Malaprade reaction. In the presence of ethylene glycol, a series of 3-hydroxymethyl-imidazo-heteroarenes was obtained in good to excellent yields. These compounds are important intermediates to access pharmaceutical drugs, e.g., Zolpidem. Furthermore, by using glycerol, bis(imidazo[1,2-a]pyridin-3-yl)methane derivatives were selectively obtained in good to excellent yields.

Copper(I/II)-Promoted Diverse Imidazo[1,2-α]pyridine Synthesis on Solid-Phase Bound DNA Oligonucleotides for Encoded Library Design

DNA-encoded libraries designed around heterocyclic scaffolds have proven highly productive in target-based screening. Here, we show the synthesis of imidazopyridines on a controlled pore glass-coupled DNA oligonucleotide for solid phase-initiated encoded library synthesis. The target compounds were synthesized by a variant of the A3 coupling reaction from aminopyridines, alkynes, and aldehydes promoted by copper(I/II) and furnished diverse substituted scaffolds with functionalities for library design. Although proceeding under forcing conditions, it produced minimal DNA damage.

'Z-trip'? A Comprehensive Overview and a Case-series of Zolpidem Misuse

Although believed safer compared to short-acting benzodiazepines (BZD), in the past few years a growing concern has developed relating to the abuse of Z-drugs, and specifically of zolpidem. Here we aim to review the evidence for the misuse of zolpidem and describe several related cases collected in Italy. A comprehensive overview is here carried by using several databases, and by combining the search strategy of free text terms and exploding a range of MESH headings relating to the topics of Zolpidem and Abuse and/or Misuse as follows: ((Zolpidem[Title/Abstract]) AND (Abuse[Title/Abstract]) OR (Misuse[Title/Abstract])), without time and/or language restrictions. Furthermore, a case series of 8 cases of zolpidem misuse and/or abuse, collected in different Italian psychiatric settings (psychiatric public hospital, psychiatric private rehabilitation clinic, and private practice), have been here described. According to our findings, zolpidem should be prescribed with the same caution as BZDs, especially in patients with a history of drug abuse or in the elderly. Behavioural modifications, including bizarre behaviours, psychomotor agitation, sleep-related complex behaviours have been reported. Monitoring of zolpidem use in selected populations is warranted. Psychiatrists and physicians should be aware of the misuse potential of zolpidem and adopt measures restricting its use.

Recent Advances in the Use of the Dimerization Strategy as a Means to Increase the Biological Potential of Natural or Synthetic Molecules

The design of C₂-symmetric biologically active molecules is a subject of interest to the scientific community. It provides the possibility of discovering medicine with higher biological potential than the parent drugs. Such molecules are generally produced by classic chemistry, considering the shortness of reaction sequence and the efficacy for each step. This review describes and analyzes recent advances in the field and emphasizes selected C₂-symmetric molecules (or axial symmetric molecules) made during the last 10 years. However, the description of the dimers is contextualized by prior work allowing its development, and they are categorized by their structure and/or by their properties. Hence, this review presents dimers composed of steroids, sugars, and nucleosides; known and synthetic anticancer agents; polyphenol compounds; terpenes, known and synthetic antibacterial agents; and natural products. A special focus on the anticancer potential of the dimers transpires throughout the review, notwithstanding their structure and/or primary biological properties.

Annulation of Conjugated Azine-Imine with a Sulfoxonium Ylide in a Noncarbenoid Route to Synthesize Multisubstituted Imidazole-Fused Heterocycles

A new [4+1]-annulation of in situ generated heterocyclic azine-aldimines with β-keto sulfoxonium ylides has been developed. The reaction constructs N-fused imidazole rings. In the reaction, the ylides play a dual-functional role of a nucleophilic 1,1-dipolar one-carbon synthon and a source of an internal oxidant, dimethyl sulfoxide, that promotes in situ dehydrogenation to product scaffolds. The method enables access to imidazo-pyridine, pyrazine, and pyrimidine heteroaromatics.

Determination of zolpidem phenyl-4-carboxylic acid and zolpidem 6-carboxylic acid in hair using gas chromatography-electron ionization-tandem mass spectrometry

A gas chromatography-electron ionization-tandem mass spectrometric (GC-EI-MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC-EI-MS/MS. The linear ranges were 8-100 pg/mg for ZPCA and 16-200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra- and inter-day precisions were within 16.9 and 11.7%, while intra- and inter-day accuracies were -7.0-8.7 and -2.8-7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9-35.9 pg/mg and ZCA 16.6-21.8 pg/mg. The method proved to be suitable for picogram-level determination of ZPCA and ZCA in human hair.

An electrolyte- and catalyst-free electrooxidative sulfonylation of imidazo[1,2-a]pyridines

An electrolyte- and catalyst-free electrooxidative C–H activation reaction is developed to afford 3-sulfonylated imidazo[1,2-a]pyridines in good to excellent yields.

8-Aminoimidazo[1,2-a]pyridine (AIP) directed Pd(ii) catalysis: site-selective ortho-C(sp2)–H arylation in aqueous medium

An efficient and facile Pd(ii) catalyzed selective ortho and β-C(sp²)–H arylation reaction employing the 8-AIP (aminoimidazo[1,2-a]pyridine) auxiliary as a removable N,N-bidentate directing group in a green solvent (water) has been reported.

Palladium catalyzed 8-aminoimidazo[1,2-a]pyridine (AIP) directed selective β-C(sp2)–H arylation

An unprecedented palladium(ii) catalyzed selective β-C(sp²)–H arylation reaction using an 8-AIP (aminoimidazo[1,2-a]pyridine) auxiliary as a new N,N-bidentate directing group has been demonstrated.

Sonication Assisted One-Pot Synthesis of Substituted Imidazopyridine from Styrene in Water

The present protocol is a simple and eco-friendly approach for the one-pot procedure for the synthesis of substituted imidazopyridines ranging from important feedstock's like styrene promoted by NBS. Through sonicator and microwave commercially available styrene with NBS in water followed by reaction with 2- aminopyridines afforded important heterocyclic scaffolds in an one-pot procedure.

Visible-Light-Induced Dehydrogenative Imidoylation of Imidazo[1,2-a]pyridines with α-Amino Acid Derivatives and α-Amino Ketones

A new and efficient visible-light-promoted dehydrogenative cross-coupling reaction of imidazo[1,2-a]pyridines with α-amino carbonyl compounds toward imidoyl imidazo[1,2-a]pyridines is developed. A diverse range of imidazo[1,2-a]pyridines undergoes the dehydrogenative imidoylation smoothly with α-amino carbonyl compounds to access the corresponding products in satisfactory yields. We have also proposed the possible reaction mechanism based on preliminary mechanistic studies. The synthetic method has the advantages of wide substrate scope, good functional tolerance, and mild reaction conditions, which make this transformation more practical and sustainable.

Relationship between plasma exposure of zolpidem and CYP2D6 genotype in healthy Korean subjects

Zolpidem, a widely prescribed hypnotic agent, is extensively metabolized by cytochrome P450 (CYP) 3A4, and CYP2C9, CYP1A2 and CYP2D6 are also involved in the metabolism of zolpidem. The aim of the study was to investigate the effects of CYP2D6 genotypes on the exposure of zolpidem. The healthy male volunteers were divided into three different genotype groups (CYP2D6*wt/*wt [*wt = *1 or *2], CYP2D6*wt/*10, and CYP2D6*10/*10). Each subject received a single oral dose of zolpidem 5 mg with or without a steady-state concentration of clarithromycin (a potent inhibitor of CYP3A4), and plasma concentrations of zolpidem were measured up to 12 h after zolpidem dosing by using liquid chromatography-tandem mass spectrometry method. When zolpidem was administered alone, the exposure of zolpidem (the total areas under the curve and the mean peak plasma concentrations) was not significantly different among three different genotype groups. Even with the steady-state concentration of clarithromycin, a potent CYP3A4 inhibitor, there were no significant differences in the exposure of zolpidem in relation to CYP2D6 genotypes.

Series of Functionalized 5-(2-Arylimidazo[1,2-a]pyridin-3-yl)pyrimidine-2,4(1H,3H)-diones: A Water-Mediated Three-Component Catalyst-Free Protocol Revisited

A water-mediated and catalyst-free practical method for the synthesis of a new series of pharmaceutically interesting functionalized 5-(2-arylimidazo[1,2-a]pyridin-3-yl)pyrimidine-2,4(1H,3H)-diones has been accomplished based on a one-pot multicomponent reaction between arylglyoxal monohydrates, 2-aminopyridines/2-aminopyrimidine, and barbituric/N,N-dimethylbarbituric acids under reflux conditions. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvents, use of water as reaction medium, clean reaction profiles, operational simplicity, ease of product isolation/purification without the aid of tedious column chromatography, good to excellent yields, and high atom-economy and low E-factor.

Temporal association between zolpidem medication and the risk of suicide: A 12-year population-based, retrospective cohort study

There have been concerns about abuse and unnecessary chronic administration of zolpidem, and zolpidem's relation to suicide risk. To investigate the temporal association of zolpidem with the risk of suicide, we conducted a 12-year, population-based, retrospective cohort study on the National Health Insurance Service-National Sample Cohort (NHIS-NSC), South Korea. Data were collected from 2002 to 2013 from the NHIS-NSC, and data cleaning was performed for 1,125,691 subjects. Cox proportional hazards regression analysis was used to investigate the correlation over time between zolpidem medication and suicide. Over intervals commencing after 80 months of observation, the adjusted hazard ratio of suicides associated with the use of the zolpidem was 2.01 (95% CI: 1.58-2.56; p < 0.001). The mean cumulative number of days of zolpidem prescription was significantly longer in the suicide group than in the non-suicide group after log-transformation (p = 0.005). Cases of chronic use of zolpidem (over six months or one year) were significantly more common in the suicide group compared to the non-suicide group (p = 0.002 and 0.005, respectively). Subjects who received zolpidem medication had a significantly higher risk of suicide after at least 80 months of observation, suggesting a long-term increased suicide risk associated with insomnia exposed to zolpidem medication.

Electro-organic synthesis of tetrahydroimidazo[1,2-a]pyridin-5(1H)-one via a multicomponent reaction

Electro-synthesis through a one-pot three-component condensation of corresponding aldehydes, Meldrum's acid, and 2-(nitromethylene)imidazolidine resulted in a series of novel tetrahydroimidazo[1,2-a]pyridine-5(1H)-one derivatives containing an electronegative pharmacophore (=CNO₂). The process was carried out in propanol medium with sodium bromide presented as electrolyte, inside an undivided cell with good to excellent yields. As a powerful entry into fused polycyclic structures related to bioactive heterocycles, this green protocol shows great potential.

Benzimidazole Containing Acetamide Derivatives Attenuate Neuroinflammation and Oxidative Stress in Ethanol-Induced Neurodegeneration

Oxidative stress-induced neuroinflammation is the prominent feature of neurodegenerative disorders, and is characterized by a gradual decline of structure and function of neurons. Many biochemical events emerge thanks to the result of this neurodegeneration, and ultimately provoke neuroinflammation, activation of microglia, and oxidative stress, leading to neuronal death. This cascade not only explains the complexity of events taking place across different stages, but also depicts the need for more effective therapeutic agents. The present study was designed to investigate the neuroprotective effects of newly synthesized benzimidazole containing acetamide derivatives, 3a (2-(4-methoxyanilino)-N-[1-(4-methylbenzene-1-sulfonyl)-1H-benzimidazol-2-yl] acetamide) and 3b (2-(Dodecylamino)-N-[1-(4-methylbenzene-1-sulfonyl)-1H-benzimidazol-2-yl] acetamide) against ethanol-induced neurodegeneration in the rat model. Both derivatives were characterized spectroscopically by proton NMR (¹H-NMR) and carbon-13 NMR (¹³C-NMR) and evaluated for neuroprotective potential using different pharmacological approaches. In vivo experiments demonstrated that ethanol triggered neurodegeneration characterized by impaired antioxidant enzymes and elevated oxidative stress. Furthermore, ethanol administration induced neuroinflammation, as demonstrated by elevated expression of tumor necrotic factor (TNF-α), nuclear factor κB (NF-κB), cyclooxygenase-2 (COX2), and ionized calcium-binding adapter molecule-1 (Iba-1), which was further validated by enzyme-linked immunosorbent assay (ELISA). Treatment with 3a and 3b ameliorated the ethanol-induced oxidative stress, neuroinflammation, and memory impairment. The affinity of synthesized derivatives towards various receptors involved in neurodegeneration was assessed through docking analysis. The versatile nature of benzimidazole nucleus and its affinity toward several receptors suggested that it could be a multistep targeting neuroprotectant. As repetitive clinical trials of neuroprotectants targeting a single step of the pathological process have failed previously, our results suggested that a neuroprotective strategy of acting at different stages may be more advantageous to intervene in the vicious cycles of neuroinflammation.