Comprehensive Insights into Medicinal Research on Imidazole-Based Supramolecular Complexes

Comparing the transfection efficiency of cationic monomer ratios in vinylimidazole and aminoethyl methacrylate copolymers

Employing polycations as non-viral gene delivery vectors has been extensively studied owing to their safety, efficiency and possibility of modifying them in an intended way compared with viral vectors. However, the main challenge is finding a biocompatible and transfection-efficient polymer. In this study, 2-aminoethyl methacrylate (A) and 1-vinyl imidazole (V) were copolymerized at three different molar ratios by a free radical polymerization method and novel biocompatible polycations with narrow molecular weight distribution were obtained. The resulting copolymers were used for condensation of plasmid DNA (pDNA) at different N/P ratios followed by physicochemical characterizations of resulting polyplexes. At N/P ratio of 2, the nanoplexes were smaller than 120 nm. The optimum formulations were stable in presence of polyanions and capable of protecting the condensed pDNA against nucleases. The polyplexes having V to A molar ratio of 1:1 were the most efficient carrier in transfecting HeLa cells and were introduced as a promising non-viral vector.

Benzo-α-pyrone-derived multitargeting actions to enhance the antibacterial performance of sulfanilamides against Escherichia coli

A novel class of benzopyrone-sulfanilamide hybrids was synthesized from phenols via multi-step reactions. Some prepared compounds effectively suppressed bacterial growth at low concentrations, and especially, sulfanilamide-hybridized 2-methyl-5-nitroimidazolyl benzopyrone 11c exhibited significant inhibitory potency against Escherichia coli (MIC = 0.0022 mM), which was 11-fold more active than clinical norfloxacin. Furthermore, compound 11c showed negligible hemolytic activity, low cytotoxicity and no drug resistance. Mechanistic studies indicated that the highly active 11c disrupted bacterial membrane integrity, reduced metabolic activity, bound DNA grooves to inhibit replication without the ability to cleave DNA, and induced reactive oxygen species (ROS) accumulation, collectively leading to bacterial death. These results highlight the potential of sulfanilamide-hybridized benzopyrones as multitarget antibacterial agents, warranting further development to combat bacterial infections.

Exploring USFDA-Approved Imidazole-Based Small Molecules in Drug Discovery: A Mini Perspective

In the present work, we have explored the importance of the imidazole ring and its importance in drug discovery, citing the key approvals in the present decade (2013-2024). The pharmacological attribution for the approved drugs revealed that out of 20 approved drugs, 45% of the approvals were made as anti-infectives, followed by approvals under the category of genetic and metabolic disorders, sexual endocrine disorders, anticancer, and to treat blood pressure, gastrointestinal disorders, and neurological conditions. Most approved drugs were dispensed through solid dosage forms (13) and thus had predominantly oral routes beside others. The metabolism pattern revealed that the drugs undergo metabolism via the involvement of multiple enzymes, where CYP3A4 and CYP3A5 were the core enzymes. The excretion pattern of these drugs revealed that the drugs are majorly excreted via the fecal route. The chemical analysis showed that pyrrolidine/pyrrole was the major heterocycle in the approved drugs, followed by the indole ring in the hybridization. Considering the substitution pattern, most drugs possessed amide, amines, and fluoro group as the functional substitution with the 2,4-substitution pattern seen in most approved drugs. Besides this, the three approved drugs were found to possess chiral centers and exhibit chirality. The article also expanded to cover the synthetic routes and metabolic routes for this versatile ring system and case studies for its utility to serve as bioisostere in drug discovery. Furthermore, this article also presents the receptor-ligand interactions of imidazole-based drugs with various target receptors. The present article is, therefore, put forth to assist medicinal chemists and chemists working in drug discovery of this versatile ring system.

A comprehensive insight into naphthalimides as novel structural skeleton of multitargeting promising antibiotics

The globally growing antimicrobial resistance seriously threatens human health, increasing efforts have been devoting to the development of novel antibiotics. Naphthalimides contain a special skeleton of cyclic double imides and the naphthalene framework, this unique structure can exert multitargeting abilities which are helpful to overcome the escalating issue of resistance. Therefore, research in connection with the development of naphthalimides as novel antimicrobial agents is becoming progressively active. It has been revealed that naphthalimides as novel structural skeleton of multitargeting promising antibiotics could not only target DNAs and enzymes, disturb membrane, produce reactive oxygen species, etc. suggesting the multitargeting actions which do not induce resistance, but also show a broad antimicrobial spectrum with safety profile and pharmacokinetic characteristics, implying large potential as a new type of antibiotics via continuous efforts toward antimicrobial naphthalimides. This review presents naphthalimides as a new type of potential antimicrobial agents and discusses rational design strategies, structure-activity relationships, and mechanisms of action, with a comprehensive view to providing a new insight for in the rational design of efficient, broad-spectrum, and low-toxic naphthalimide antibiotics.

Unlocking the Antibacterial Potential of Naphthalimide-Coumarins to Overcome Drug Resistance with Antibiofilm and Membrane Disruption Ability against Escherichia coli

Resistance by bacteria to available antibiotics is a threat to human health, which demands the development of new antibacterial agents. Considering the prevailing conditions, we have developed a library of new naphthalimide-coumarin moieties as broad-spectrum antibacterial agents to fight against awful drug resistance. Preliminary studies indicate that compounds 8e and 8h display excellent antibacterial activity against Escherichia coli, exceeding the performance of marketed drug amoxicillin. These drug candidates effectively inhibit biofilm formation and disrupt the biofilm virulence factor, which is accountable for the formation of strong biofilm. In addition to this, both compounds exhibit fast bactericidal properties, thus shortening the time of treatment and resisting the emergence of drug resistance for up to 20 passages. Further, biofunctional evaluation reveals that both compounds effectively disrupt the membrane, causing the leakage of cytoplasmic contents and loss in metabolic activity. Both compounds 8e and 8h efficiently induce the ROS, leading to the oxidation of GSH to GSSG, decreasing the GSH activity of the cell, and causing oxidative damage to the cells. Additionally, both compounds effectively bind with DNA to block DNA replication and form supramolecular complexes, thus exhibiting antibacterial activity. Moreover, these compounds readily bind human serum albumin with high binding constants and can be transported to the target site easily. These findings reveal that newly synthesized naphthalimide-coumarin conjugates have the potential to build as potent antibacterial agents and can be used further for clinical trials.

Discovery of Quinazolone Pyridiniums as Potential Broad-Spectrum Antibacterial Agents

The overprescription of antibiotics in medicine and agriculture has accelerated the development and spread of antibiotic resistance in bacteria, which severely limits the arsenal available to clinicians for treating bacterial infections. This work discovered a new class of heteroarylcyanovinyl quinazolones and quinazolone pyridiniums to surmount the increasingly severe bacterial resistance. Bioactive assays manifested that the highly active compound 19a exhibited strong inhibition against MRSA and Escherichia coli with extremely low MICs of 0.5 μg/mL, being eightfold more active than that of norfloxacin (MICs = 4 μg/mL). The highly active 19a with rapid bactericidal properties displayed imperceptible resistance development trends, negligible hemolytic toxicity, and effective biofilm inhibitory effects. Preliminary explorations on antibacterial mechanisms revealed that compound 19a could cause membrane damage, embed in intracellular DNA to hinder bacterial DNA replication, and induce metabolic dysfunction. Surprisingly, active 19a was found to trigger the conformational change in PBP2a of MRSA to open the active site, which might account for its high inhibition against MRSA. In addition, the little effect of molecule 19a on the production of reactive oxygen species indicated that bacterial death was not caused by oxidative stress. The above comprehensive analyses highlighted the large potential of quinazolone pyridiniums as multitargeting broad-spectrum antibacterial agents.

Sulfoxidation of pyrimidine thioate derivatives and study their biological activities

In a quest to innovate biologically active molecules, the benzoylation of 4,6-dimethylpyrimidine-2-thiol hydrochloride (1) with benzoyl chloride derivatives was employed to produce a series of pyrimidine benzothioate derivatives (2-5). Subsequent sulfoxidation of these derivatives (2-5) using hydrogen peroxide and glacial acetic acid yielded a diverse array of pyrimidine sulfonyl methanone derivatives (6-9). In parallel, the sulfoxidation of pyrimidine sulfonothioates (10-12) yielded sulfonyl sulfonyl pyrimidines (13-15), originating from the condensation of compound 1 with sulfonyl chloride derivatives. The newly synthesized compounds underwent characterization via FT-IR, NMR, mass spectrometry, and elemental analyses. Biological screenings unveiled interesting properties: compounds 1 and 6 exhibited significant antimicrobial potency against S. epidermidis and S. haemolyticus, whereas compound 11 showed distinct insensitivity. Excitingly, compounds 12 and 6 showcased robust antioxidant activity by efficiently scavenging DPPH• radical, underscoring their potential in oxidative stress mitigation. Notably, compounds 10 and 12 displayed promising anti-tumor effects, with compound 12 demonstrating superior efficacy against the MCF-7 breast cancer cell line compared to compound 10. The study revealed a spectrum of biological activities across the synthesized derivatives, with modifications often resulting in diminished bioactivity compared to the parent compound 1. These findings shed light on the intricate relationship between chemical modifications and biological properties, offering valuable insights for future drug discovery endeavors.

Assembly-enhanced indocyanine green nanoparticles for fluorescence imaging-guided photothermal therapy

The development of theranostic agents that offer complete biocompatibility, coupled with enhanced diagnostic and therapeutic performance, is crucial for fluorescence imaging-guided photothermal therapy in anti-tumor applications. However, the fabrication of nanotheranostics meeting the aforementioned requirements is challenged by concerns regarding biosafety and limited control over construction. Herein, we reported a class of fluorescence imaging-guided photothermal theranostic nanomaterials that are composed of amino acid derivatives and clinically used small photoactive indocyanine green molecules. Through manipulation of noncovalent interactions, these binary building blocks can co-assemble into nanoparticles in a tunable manner. Significantly, such construction not only maintained the fluorescence properties of photoactive molecules, but also enhanced their stability to overcome barriers from photodegradation and complex physiological conditions. These collective features integrated their precise anti-tumor applications, including fluorescence imaging diagnosis and photothermal ablation therapy. This study reported a class of nanotheranostics characterized by biocompatibility, adjustable construction, and robust stability, which are beneficial for the clinical translation of fluorescence imaging-guided photothermal therapy against tumors.

Cardioprotective effects of cinnamoyl imidazole on apoptosis and oxidative stress in hypoxia/reoxygenation-induced H9C2 cell lines

BACKGROUND

This study explored the effects of cinnamoyl imidazole on alleviating oxidative stress and apoptosis in hypoxia/reoxygenation (H/R)-induced H9C2 cells, using computational analysis with in-vitro validation.

METHODS

Computational techniques, including SwissADME and Swiss Target Prediction, were employed to predict the ADME properties and to identify targets of cinnamoyl imidazole. Differential gene expression (DEG) analysis was conducted on myocardial infarction (MI) datasets obtained from the Gene Expression Omnibus. Gene enrichment and molecular simulation studies were done to focus on apoptotic pathways. The computational findings were validated through In vitro experiments on H9C2 cardiomyocytes subjected to 8 h of hypoxia followed by 24 h of reoxygenation. Antioxidant enzyme levels (catalase, GST, GSH-Px, and SOD), mitochondrial membrane potential (ΔΨm), caspase-3 activity, and the expression of CASP3, MAPK8, JAK2, and BCL2L1 were assessed.

RESULTS

Cinnamoyl imidazole has demonstrated favourable pharmacokinetic properties, characterized by high gastrointestinal absorption and low toxicity with negative toxicity for organ endpoints. Molecular docking studies revealed the strong binding affinities for CASP3, MAPK8, and JAK2. In vitro results showed a significant increase in cell viability (94.7 % at 10 μM, p < 0.001) and antioxidant enzyme activity, along with a 64.3 % reduction in caspase-3 activity at 1000 μM (p < 0.01). Cinnamoyl imidazole treatment preserved mitochondrial membrane potential, downregulated pro-apoptotic genes CASP3 and MAPK8, and upregulated the anti-apoptotic gene BCL2L1.

CONCLUSION

Cinnamoyl imidazole effectively mitigates oxidative stress and apoptosis in H/R-induced H9C2 cells, enhancing cell viability and antioxidant defenses while maintaining mitochondrial integrity.

Design and synthesis of coumarin-based amphoteric antimicrobials with biofilm interference and immunoregulation effects

Bacterial infections pose a threat to human and animal health, and the formation of biofilm exacerbates the microbial threat. New antimicrobial agents to address this challenge are much needed. In this study, several new amphoteric compounds derived from the natural product coumarin were designed and synthesized by mimicking the structure and function of antimicrobial peptides. Strong inhibitory effect of 8b was observed on S. aureus 29213 and five isolated clinically positive strains, with an MIC value of 1-4 μg mL-1, accompanied by the potential advantages of rapid sterilization and no drug resistance. The in vivo activity of 8b was supported by good antibacterial and anti-inflammatory effects in a mouse wound infection model. More importantly, good immunomodulatory effects, inhibition of biofilm formation, and biofilm clearance were detected in the treatment using 8b, which makes it a potential candidate antibacterial for controlling S. aureus infections forming biofilm.

Synthesis and antibacterial medicinal evaluation of carbothioamido hydrazonyl thiazolylquinolone with multitargeting antimicrobial potential to combat increasingly global resistance

The global microbial resistance is a serious threat to human health, and multitargeting compounds are considered to be promising to combat microbial resistance. In this work, a series of new thiazolylquinolones with multitargeting antimicrobial potential were developed through multi-step reactions using triethoxymethane and substituted anilines as start materials. Their structures were confirmed by 1H NMR, 13C NMR and HRMS spectra. Antimicrobial evaluation revealed that some of the target compounds could effectively inhibit microbial growth. Especially, carbothioamido hydrazonyl aminothiazolyl quinolone 8a showed strong inhibitory activity toward drug-resistant Staphylococcus aureus with MIC value of 0.0047 mM, which was 5-fold more active than that of norfloxacin. The highly active compound 8a exhibited negligible hemolysis, no significant toxicity in vitro and in vivo, low drug resistance, as well as rapidly bactericidal effects, which suggested its favorable druggability. Furthermore, compound 8a was able to effectively disrupt the integrity of the bacterial membrane, intercalate into DNA and inhibit the activity of topoisomerase IV, suggesting multitargeting mechanism of action. Compound 8a could form hydrogen bonds and hydrophobic interactions with DNA-topoisomerase IV complex, indicating the insertion of aminothiazolyl moiety was beneficial to improve antibacterial efficiency. These findings indicated that the active carbothioamido hydrazonyl aminothiazolyl quinolone 8a as a chemical therapeutic candidate demonstrated immense potential to tackle drug-resistant bacterial infections.

A Benzimidazole-Based N-Heterocyclic Carbene Derivative Exhibits Potent Antiproliferative and Apoptotic Effects against Colorectal Cancer

Background and Objectives: Colorectal cancer (CRC) remains a major global health issue. Although chemotherapy is the first-line treatment, its effectiveness is limited due to drug resistance developed in CRC. To overcome resistance and improve the prognosis of CRC patients, investigating new therapeutic approaches is necessary. Materials and Methods: Using human colorectal adenocarcinoma (HT29) and metastatic CRC (SW620) cell lines, the potential anticancer properties of a newly synthesized compound 1-(Isobutyl)-3-(4-methylbenzyl) benzimidazolium chloride (IMBZC) were evaluated by performing MTT cytotoxicity, cell migration, and colony formation assays, as well as by monitoring apoptosis-related protein and gene expression using Western blot and reverse transcription-quantitative polymerase chain reaction technologies. Results: Tested at various concentrations, the half-maximal inhibitory concentrations (IC50) of IMBZC on HT29 and SW620 cell growth were determined to be 22.13 µM (6.97 μg/mL) and 15.53 µM (4.89 μg/mL), respectively. IMBZC did not alter the cell growth of normal HEK293 cell lines. In addition, IMBZC inhibited cell migration and significantly decreased colony formation, suggesting its promising role in suppressing cancer metastasis. Mechanistic analyses revealed that IMBZC treatment increased the expression of pro-apoptotic proteins p53 and Bax, while decreasing the expression of anti-apoptotic proteins Bcl-2 and Bcl-xL, thus indicating the induction of apoptosis in IMBZC-treated CRC cells, compared to untreated cells. Additionally, the addition of IMBZC to conventional chemotherapeutic drugs (i.e., 5-fluorouracil, irinotecan, and oxaliplatin) resulted in an increase in the cytotoxic potential of the drugs. Conclusions: This study suggests that IMBZC has substantial anticancer effects against CRC cells through its ability to induce apoptosis, inhibit cancer cell migration and colony formation, and enhance the cytotoxic effects of conventional chemotherapeutic drugs. These findings indicate that IMBZC could be a promising chemotherapeutic drug for the treatment of CRC. Further research should be conducted using in vivo models to confirm the anti-CRC activities of IMBZC.

Unique aminothiazolyl coumarins as potential DNA and membrane disruptors towards Enterococcus faecalis

Aminothiazolyl coumarins as potentially new antimicrobial agents were designed and synthesized in an effort to overcome drug resistance. Biological activity assay revealed that some target compounds exhibited significantly inhibitory efficiencies toward bacteria and fungi including drug-resistant pathogens. Especially, aminothiazolyl 7-propyl coumarin 8b and 4-dichlorobenzyl derivative 11b exhibited bactericidal potential (MBC/MIC = 2) toward clinically drug-resistant Enterococcus faecalis with low cytotoxicity to human lung adenocarcinoma A549 cells, rapidly bactericidal effects and no obvious bacterial resistance development against E. faecalis. The preliminary antibacterial action mechanism studies suggested that compound 11b was able to disturb E. faecalis membrane effectively, and interact with bacterial DNA isolated from resistant E. faecalis through noncovalent bonds to cleave DNA, thus inhibiting the growth of E. faecalis strain. Further molecular modeling indicated that compounds 8b and 11b could bind with SER-1084 and ASP-1083 residues of gyrase-DNA complex through hydrogen bonds and hydrophobic interactions. Moreover, compound 11b showed low hemolysis and in vivo toxicity. These findings of aminothiazolyl coumarins as unique structural scaffolds might hold a large promise for the treatments of drug-resistant bacterial infection.

Anti-Infection of Oral Microorganisms from Herbal Medicine of Piper crocatum Ruiz & Pav

The WHO Global Status Report on Oral Health 2022 reveals that oral diseases caused by infection with oral pathogenic microorganisms affect nearly 3.5 billion people worldwide. Oral health problems are caused by the presence of S. mutans, S. sanguinis, E. faecalis and C. albicans in the oral cavity. Synthetic anti-infective drugs have been widely used to treat oral infections, but have been reported to cause side effects and resistance. Various strategies have been implemented to overcome this problem. Synthetic anti-infective drugs have been widely used to treat oral infections, but they have been reported to cause side effects and resistance. Therefore, it is important to look for safe anti-infective alternatives. Ethnobotanical and ethnopharmacological studies suggest that Red Betel leaf (Piper crocatum Ruiz & Pav) could be a potential source of oral anti-infectives. This review aims to discuss the pathogenesis mechanism of several microorganisms that play an important role in causing health problems, the mechanism of action of synthetic oral anti-infective drugs in inhibiting microbial growth in the oral cavity, and the potential of red betel leaf (Piper crocatum Ruiz & Pav) as an herbal oral anti-infective drug. This study emphasises the importance of researching natural components as an alternative treatment for oral infections that is more effective and can meet global needs.

Cyanomethylquinolones as a New Class of Potential Multitargeting Broad-Spectrum Antibacterial Agents

This work identified a class of cyanomethylquinolones (CQs) and their carboxyl analogues as potential multitargeting antibacterial candidates. Most of the prepared compounds showed high antibacterial activities against most of the tested bacteria, exhibiting lower MIC values (0.125-2 μg/mL) than those of clinical norfloxacin, ciprofloxacin, and clinafloxacin. The low hemolysis, drug resistance, and cytotoxicity, as well as good predictive pharmacokinetics of active CQs and carboxyl analogues revealed their development potential. Furthermore, they could eradicate the established biofilm, facilitating bacterial exposure to these antibacterial candidates. These active compounds could induce bacterial death through multitargeting effects, including intercalating into DNA, up-regulating reactive oxygen species, damaging membranes directly, and impeding metabolism. Moreover, the highly active cyclopropyl CQ 15 exhibited more effective in vivo anti-MRSA potency than ciprofloxacin. These findings highlight the potential of CQs and their carboxyl analogues as multitargeting broad-spectrum antibacterial candidates for treating intractable bacterial infections.

A Unique Hybridization Route to Access Hydrazylnaphthalimidols as Novel Structural Scaffolds of Multitargeting Broad-Spectrum Antifungal Candidates

This study developed a class of novel structural antifungal hydrazylnaphthalimidols (HNs) with multitargeting broad-spectrum potential via multicomponent hybridization to confront increasingly severe fungal invasion. Some prepared HNs exhibited considerable antifungal potency; especially nitrofuryl HN 4a (MIC = 0.001 mM) exhibited a potent antifungal activity against Candida albicans, which is 13-fold higher than that of fluconazole. Furthermore, nitrofuryl HN 4a displayed low cytotoxicity, hemolysis and resistance, as well as a rapid fungicidal efficacy. Preliminary mechanistic investigations revealed that nitrofuryl HN 4a could inhibit lactate dehydrogenase to decrease metabolic activity and promote the accumulation of reactive oxygen species, leading to oxidative stress. Moreover, nitrofuryl HN 4a did not exhibit membrane-targeting ability; it could embed into DNA to block DNA replication but could not cleave DNA. These findings implied that HNs are promising as novel structural scaffolds of potential multitargeting broad-spectrum antifungal candidates for treating fungal infection.

Three-component cascade reaction of 3-ketonitriles, 2-unsubstituted imidazole N-oxides, and aldehydes

A three-component condensation of 2-unsubstituted imidazole N-oxides, 3-ketonitriles, and aldehydes is described. The reaction proceeds via sequential Knoevenagel condensation/Michael addition under mild, catalyst-free conditions with various substrates. Furthermore, the corresponding 2-functionalized imidazole N-oxides can be further dehydrated to (Z)-2-aroyl-3-(1H-imidazol-2-yl)-acrylonitriles, which may also be directly prepared by changing the reaction conditions as a cascade of Knoevenagel condensation/Michael addition/dehydration.

Synthesis and in silico inhibitory action studies of azo-anchored imidazo[4,5-b]indole scaffolds against the COVID-19 main protease (Mpro)

The present work elicits a novel approach to combating COVID-19 by synthesizing a series of azo-anchored 3,4-dihydroimidazo[4,5-b]indole derivatives. The envisaged methodology involves the L-proline-catalyzed condensation of para-amino-functionalized azo benzene, indoline-2,3-dione, and ammonium acetate precursors with pertinent aryl aldehyde derivatives under ultrasonic conditions. The structures of synthesized compounds were corroborated through FT-IR, 1H NMR, 13C NMR, and mass analysis data. Molecular docking studies assessed the inhibitory potential of these compounds against the main protease (Mpro) of SARS-CoV-2. Remarkably, in silico investigations revealed significant inhibitory action surpassing standard drugs such as Remdesivir, Paxlovid, Molnupiravir, Chloroquine, Hydroxychloroquine (HCQ), and (N3), an irreversible Michael acceptor inhibitor. Furthermore, the highly active compound was also screened for cytotoxicity activity against HEK-293 cells and exhibited minimal toxicity across a range of concentrations, affirming its favorable safety profile and potential suitability. The pharmacokinetic properties (ADME) of the synthesized compounds have also been deliberated. This study paves the way for in vitro and in vivo testing of these scaffolds in the ongoing battle against SARS-CoV-2.

Discovery of indolylacryloyl-derived oxacins as novel potential broad-spectrum antibacterial candidates

The emergence of serious bacterial resistance towards clinical oxacins poses a considerable threat to global public health, necessitating the development of novel structural antibacterial agents. Seven types of novel indolylacryloyl-derived oxacins (IDOs) were designed and synthesized for the first time from commercial 3,4-difluoroaniline via an eight-step procedure. The synthesized compounds were characterized by modern spectroscopic techniques. All target molecules were evaluated for antimicrobial activities. Most of the prepared IDOs showed a broad antibacterial spectrum and strong activities against the tested strains, especially ethoxycarbonyl IDO 10d (0.25-0.5 μg/mL) and hydroxyethyl IDO 10e (0.25-1 μg/mL) exhibited much superior antibacterial efficacies to reference drug norfloxacin. These highly active IDOs also displayed low hemolysis, cytotoxicity and resistance, as well as rapid bactericidal capacity. Further investigations indicated that ethoxycarbonyl IDO 10d and hydroxyethyl IDO 10e could effectively reduce the exopolysaccharide content and eradicate the formed biofilm, which might delay the development of drug resistance. Preliminary exploration of the antibacterial mechanism revealed that active IDOs could not only destroy membrane integrity, resulting in changes in membrane permeability, but also promote the accumulation of reactive oxygen species, leading to the production of malondialdehyde and decreased bacterial metabolism. Moreover, they exhibited the capability to bind with DNA and DNA gyrase, forming supramolecular complexes through various noncovalent interactions, thereby inhibiting DNA replication and causing bacterial death. All the above results suggested that the newly developed indolylacryloyl-derived oxacins should hold great promise as potential multitargeting broad-spectrum antibacterial candidates to overcome drug resistance.

Novel aminothiazoximone-corbelled ethoxycarbonylpyrimidones with antibiofilm activity to conquer Gram-negative bacteria through potential multitargeting effects

The emergence of drug-resistant microorganisms threatens human health, and it is usually exacerbated by the formation of biofilm, which forces the development of new antibacterial agents with antibiofilm activity. In this work, a novel category of aminothiazoximone-corbelled ethoxycarbonylpyrimidones (ACEs) was designed and synthesized, and some of the prepared ACEs showed potent bioactivity against the tested bacteria. In particular, imidazolyl ACE 6c showed better inhibitory activity towards Acinetobacter baumannii and Escherichia coli with MIC values both of 0.0066 mmol/L than norfloxacin. It was also revealed that imidazolyl ACE 6c not only possessed inconspicuous hemolytic rate and cytotoxicity, low drug resistance and no risk of penetrating the blood-brain barrier, but also exhibited obvious biofilm inhibition and eradication activities. The preliminary mechanism research suggested that imidazolyl ACE 6c could induce metabolic dysfunction by deactivating lactate dehydrogenase and promote the accumulation of reactive oxygen species to decrease the reduced glutathione and ultimately cause oxidative damage in bacteria. Furthermore, ACE 6c was also found that could insert into DNA to form the supramolecular complex of 6c-DNA and trigger cell death. The multidimensional effect might promote bacterial cell rupture, leading to the leakage of intracellular content. These findings manifested that novel imidazolyl ACE 6c as a potential multitargeting antibacterial agent with potent antibiofilm activity could provide new possibility for the treatment of refractory biofilm-intensified bacterial infections.

Discovery of benzopyridone cyanoacetates as new type of potential broad-spectrum antibacterial candidates

Unique benzopyridone cyanoacetates (BCs) as new type of promising broad-spectrum antibacterial candidates were discovered with large potential to combat the lethal multidrug-resistant bacterial infections. Many prepared BCs showed broad antibacterial spectrum with low MIC values against the tested strains. Some highly active BCs exhibited rapid sterilization capacity, low resistant trend and good predictive pharmacokinetic properties. Furthermore, the highly active sodium BCs (NaBCs) displayed low hemolysis and cytotoxicity, and especially octyl NaBC 5g also showed in vivo potent anti-infective potential and appreciable pharmacokinetic profiles. A series of preliminary mechanistic explorations indicated that these active BCs could effectively eliminate bacterial biofilm and destroy membrane integrity, thus resulting in the leakage of bacterial cytoplasm. Moreover, their unique structures might further bind to intracellular DNA, DNA gyrase and topoisomerase IV through various direct noncovalent interactions to hinder bacterial reproduction. Meanwhile, the active BCs also induced bacterial oxidative stress and metabolic disturbance, thereby accelerating bacterial apoptosis. These results provided a bright hope for benzopyridone cyanoacetates as potential novel multitargeting broad-spectrum antibacterial candidates to conquer drug resistance.

A Novel Recyclable Magnetic Nano-Catalyst for Fenton-Photodegradation of Methyl Orange and Imidazole Derivatives Catalytic Synthesis

A magnetite chlorodeoxycellulose/ferroferric oxide (CDC@Fe3O4) heterogeneous photocatalyst was synthesised via treated and modified cotton in two steps. The designed nanocomposites were characterised by FTIR, TGA, XRD, SEM, and VSM analyses. The Fenton-photocatalytic decomposition efficiency of the synthesised magnetic catalyst was evaluated under visible sunlight using Methyl Orange (MO) as a model organic pollutant. The impacts of several degradation parameters, including the light source, catalyst load, irradiation temperature, oxidant dose, and pH of the dye aqueous solution and its corresponding concentration on the Fenton photodegradation performance, were methodically investigated. The (CDC@Fe3O4) heterogeneous catalyst showed a remarkable MO removal rate of 97.9% at 10 min under visible-light irradiation. (CDC@Fe3O4) nanomaterials were also used in a heterogeneous catalytic optimised protocol for a multicomponent reaction procedure to obtain nine tetra-substituted imidazole derivatives. The green protocol afforded imidazole derivatives in 30 min with good yields (91-97%) at room temperature and under ultrasound irradiation. Generally, a synthesised recyclable heterogeneous nano-catalyst is a good example and is suitable for wastewater treatment and organic synthesis.

Benzopyrone-mediated quinolones as potential multitargeting antibacterial agents

A new type of benzopyrone-mediated quinolones (BMQs) was rationally designed and efficiently synthesized as novel potential antibacterial molecules to overcome the global increasingly serious drug resistance. Some synthesized BMQs effectively suppressed the growth of the tested strains, outperforming clinical drugs. Notably, ethylidene-derived BMQ 17a exhibited superior antibacterial potential with low MICs of 0.5-2 μg/mL to clinical drugs norfloxacin, it not only displayed rapid bactericidal performance and inhibited bacterial biofilm formation, but also showed low toxicity toward human red blood cells and normal MDA-kb2 cells. Mechanistic investigation demonstrated that BMQ 17a could effectually induce bacterial metabolic disorders and promote the enhancement of reactive oxygen species to disrupt the bacterial antioxidant defense system. It was found that the active molecule BMQ 17a could not only form supramolecular complex with lactate dehydrogenase, which disturbed the biological functions, but also effectively embed into calf thymus DNA, thus affecting the normal function of DNA and achieving cell death. This work would provide an insight into developing new molecules to reduce drug resistance and expand antibacterial spectrum.

Identification of unique indolylcyanoethylenyl sulfonylanilines as novel structural scaffolds of potential antibacterial agents

The increasing incidence of antibiotic resistance has forced the development of unique antimicrobials with novel multitargeting mechanisms to combat infectious diseases caused by multidrug-resistant pathogens. Structurally unique indolylcyanoethylenyl sulfonylanilines (ISs) were exploited as novel promising antibacterial agents to confront stubborn drug resistance. Some prepared ISs possessed favorable bacteriostatic action towards the tested bacteria. Especially, hydroxyethyl IS 14a exerted 8-fold more potent inhibitory efficacy against multidrug-resistant A. baumannii and E. coli 25922 with the low MIC of 0.5 μg/mL than norfloxacin, and showed low cell toxicity and rapid bactericidal property. Moreover, this compound also possessed obvious effect of eradicating bacterial biofilm, which could effectually relieve the development of drug resistance. A preliminary assessment of the antibacterial mechanism indicated that compound 14a could disintegrate membrane integrity leading to the leakage of intracellular protein, inactivation of lactate dehydrogenase and metabolism inhibition. Hydroxyethyl IS 14a mediated the accumulation of excess reactive oxygen species, which further contributed to reducing glutathione, resulting in oxidative damage to bacteria. Furthermore, IS 14a could intercalate into DNA to hinder the biological function of DNA. Quantum chemical study disclosed that IS 14a with the lowest energy gap was conducive to displaying high bioactivity. These findings demonstrated that hydroxyethyl IS 14a as a prospective antimicrobial candidate for combating A. baumannii and E. coli 25922 would be a promising starting point.

Design, Synthesis, and Anti-Breast Cancer Potential of Imidazole-Pyridine Hybrid Molecules In Vitro and Ehrlich Ascites Carcinoma Growth Inhibitory Activity Assessment In Vivo

Breast cancer remains a challenging medical issue and is a high priority for biomedical research despite significant advancements in cancer research and therapy. The current study aims to determine the anticancer activity of a group of imidazole-pyridine-based scaffolds against a variety of breast cancer cell lines differing in their receptor expression (estrogen receptor (ER), progesterone receptor (PR), and HER-2). A series of 10 molecules (coded 5a-5j) were synthesized through multicomponent and alkylation reactions. FTIR, MS, 1H, and 13C NMR spectral analyses confirmed the structures and purity of the synthesized molecules. Subsequently, these molecules were tested for their ability to inhibit the viability of cell lines representing carcinoma of the breast, viz., MDA-MB-468 (ER-, PR-, and HER-), BT-474 (ER+, PR+, and HER+), T-47D (ER+, PR+, and HER-), and MCF-7 (ER+, PR+, and HER-) in vitro. Among these 10 molecules, 5a, 5c, 5d, and 5e exhibited better potency, as evidenced by IC50 < 50 μM at 24 h of treatment against BT-474 and MDA-MB-468 cell lines. However, except for 5d, the IC50 value is much higher than 50 μM when tested against T47D and MCF-7 cell lines at 24h. Extended treatment for 48 h reduced the effect of these molecules, as an increase in IC50 was observed. In mice, intraperitoneal administration of 5e retarded the Ehrlich ascites carcinoma (EAC) growth without causing any organ toxicity at the doses tested. In summary, we report the synthesis scheme and key structural requirements for a new series of imidazole-pyridine molecules for in vitro inhibition of the feasibility of breast cancer cells and in vivo inhibition of EAC tumors.

Imidazoles as Serotonin Receptor Modulators for Treatment of Depression: Structural Insights and Structure-Activity Relationship Studies

Serotoninergic signaling is identified as a crucial player in psychiatric disorders (notably depression), presenting it as a significant therapeutic target for treating such conditions. Inhibitors of serotoninergic signaling (especially selective serotonin reuptake inhibitors (SSRI) or serotonin and norepinephrine reuptake inhibitors (SNRI)) are prominently selected as first-line therapy for the treatment of depression, which benefits via increasing low serotonin levels and norepinephrine by blocking serotonin/norepinephrine reuptake and thereby increasing activity. While developing newer heterocyclic scaffolds to target/modulate the serotonergic systems, imidazole-bearing pharmacophores have emerged. The imidazole-derived pharmacophore already demonstrated unique structural characteristics and an electron-rich environment, ultimately resulting in a diverse range of bioactivities. Therefore, the current manuscript discloses such a specific modification and structural activity relationship (SAR) of attempted derivatization in terms of the serotonergic efficacy of the resultant inhibitor. We also featured a landscape of imidazole-based development, focusing on SAR studies against the serotoninergic system to target depression. This study covers the recent advancements in synthetic methodologies for imidazole derivatives and the development of new molecules having antidepressant activity via modulating serotonergic systems, along with their SAR studies. The focus of the study is to provide structural insights into imidazole-based derivatives as serotonergic system modulators for the treatment of depression.

Novel Thiazolylketenyl Quinazolinones as Potential Anti-MRSA Agents and Allosteric Modulator for PBP2a

Bacterial infections caused by methicillin-resistant Staphylococcus aureus have seriously threatened public health. There is an urgent need to propose an existing regimen to overcome multidrug resistance of MRSA. A unique class of novel anti-MRSA thiazolylketenyl quinazolinones (TQs) and their analogs were developed. Some synthesized compounds showed good bacteriostatic potency. Especially TQ 4 was found to exhibit excellent inhibition against MRSA with a low MIC of 0.5 μg/mL, which was 8-fold more effective than norfloxacin. The combination of TQ 4 with cefdinir showed stronger antibacterial potency. Further investigation revealed that TQ 4, with low hemolytic toxicity and low drug resistance, was not only able to inhibit biofilm formation but also could reduce MRSA metabolic activity and showed good drug-likeness. Mechanistic explorations revealed that TQ 4 could cause leakage of proteins by disrupting membrane integrity and block DNA replication by intercalated DNA. Furthermore, the synergistic antibacterial effect with cefdinir might be attributed to TQ 4 with the ability to induce PBP2a allosteric regulation of MRSA and further trigger the opening of the active site to promote the binding of cefdinir to the active site, thus inhibiting the expression of PBP2a, thereby overcoming MRSA resistance and significantly enhancing the anti-MRSA activity of cefdinir. A new strategy provided by these findings was that TQ 4, possessing both excellent anti-MRSA activity and allosteric effect of PBP2a, merited further development as a novel class of antibacterial agents to overcome increasingly severe MRSA infections.