Application and synthesis of thiazole ring in clinically approved drugs

Identification of hydroxyphenyl cyanovinyl thiazoles as new structural scaffold of potential antibacterial agents

Unique hydroxyphenyl cyanovinyl thiazoles (HCTs) as new structural scaffolds of potential antibacterial agents were developed to overcome global increasingly serious drug resistance. Some synthesized HCTs could suppress the growth of the tested strains, especially, benzothiophenyl HCT 5c exhibited superior anti-Escherichia coli activity with a lower MIC of 0.5 μg/mL to norfloxacin (MIC = 1 μg/mL). The active benzothiophenyl HCT 5c displayed no obvious hemolysis, low cytotoxicity and a much lower trend for the development of drug-resistance than norfloxacin. Further exploration revealed that benzothiophenyl HCT 5c could intercalate to DNA to form a DNA-5c complex, which disturbed the biological functions to facilitate bacterial death. ADME analysis indicated that compound 5c possessed favorable druggability and promising pharmacokinetic properties. This work provided an insight into further developing hydroxyphenyl cyanovinyl thiazoles as new structural scaffold of promising antibacterial candidates.

The Liebeskind-Srogl cross-coupling reaction towards the synthesis of biologically active compounds

In this review, we emphasize the significance of the Liebeskind-Srogl cross-coupling reaction, a palladium-catalyzed process involving the reaction between a thioester and a boronic acid. This reaction has emerged as a fundamental technique in synthetic methodologies aimed at the development of biologically active compounds. The Liebeskind-Srogl cross-coupling method has become an essential approach in chemistry, facilitating the diversification of complex structures that would be significantly more challenging to synthesize through alternative approaches. In this review, we aim to outline the numerous possibilities for preparing a wide range of derivatives, each with notable biological potential.

Exploring the Potential of Pyridine Carboxylic Acid Isomers to Discover New Enzyme Inhibitors

Pyridine carboxylic acid isomers - picolinic acid, nicotinic acid, and isonicotinic acid - have historically resulted in a plethora of drugs against tuberculosis, cancer, diabetes, Alzheimer's, angina, dementia, depression, allergy, respiratory acidosis, psoriasis, acne, hypertension, hyperlipidemia, HIV/AIDS (specifically HIV-1), among others. Despite the large number of therapeutic agents derived from these isomers, the research involving these scaffolds is still exceptionally active. The current surge in enzyme inhibitory activities by the compounds derived from them has further created space for the discovery of new drug candidates. This review focuses on the medicinal relevance of these isomers by analyzing structure-activity relationships (SARs) and highlighting emerging trends from patents filed over the last decade. Notably, pharmaceutical giants like Bayer, Bristol-Myers Squibb, Novartis, Curis, and Aurigene have developed enzyme inhibitors based on these scaffolds with nanomolar potency. The role of these isomers in the development of antiviral agents, including protease inhibitors, is also discussed. Overall, this review brings to the readers, a pragmatic opportunity to comprehend the recent literature, highlighting the scaffolds' importance in the design of new enzyme inhibitors. Furthermore, it discusses the structure-activity relationship of pyridine carboxylic acid-derived compounds and highlights the current patenting trends in medicinal chemistry.

Identification of 3-[(4-Acetylphenyl)(4-Phenylthiazol-2-Yl)Amino]Propanoic Acid Derivatives as Promising Scaffolds for the Development of Novel Anticancer Candidates Targeting SIRT2 and EGFR

Background: A series of novel polysubstituted thiazole derivatives were synthesized, and their antiproliferative properties were evaluated using both 2D and 3D lung cancer models. Methods: The compounds were obtained via esterification, oximation, hydrazinolysis, and condensation reactions. Results: Structure-activity relationship analysis revealed that the antiproliferative activity was structure-dependent. Notably, oxime derivatives 21 and 22, along with carbohydrazides 25 and 26, exhibited low micromolar activity that was significantly greater than that of cisplatin (p < 0.005), a standard chemotherapeutic agent. These compounds demonstrated potent, antiproliferative activity against H69 small-cell lung carcinoma cells, as well as anthracycline-resistant H69AR cells. Moreover, compounds 21, 22, 25, and 26 effectively induced cell death in A549 agarose-based 3D spheroids, further supporting their potential therapeutic application. The in silico studies proposed that compound 22 is able to interact with human SIRT2 and EGFR via conserved amino acid residues. Conclusions: The ability of these thiazole derivatives to target both drug-sensitive and drug-resistant lung cancer models highlights their promise as scaffolds for further optimization and preclinical development. Future studies will focus on structural modifications to enhance potency, selectivity, and pharmacokinetic properties, paving the way for the development of novel thiazole-based antiproliferative agents.

Game Changers: Blockbuster Small-Molecule Drugs Approved by the FDA in 2024

This article profiles 27 innovative advancements in small-molecule drugs approved by the U.S. Food and Drug Administration (FDA) in 2024. These drugs target various therapeutic areas including non-small cell lung cancer, advanced or metastatic breast cancer, glioma, relapsed or refractory acute leukemia, urinary tract infection, Staphylococcus aureus bloodstream infections, nonalcoholic steatohepatitis, primary biliary cholangitis, Duchenne muscular dystrophy, hypertension, anemia due to chronic kidney disease, extravascular hemolysis, primary axillary hyperhidrosis, chronic obstructive pulmonary disease, severe alopecia areata, WHIM syndrome, Niemann-Pick disease type C, schizophrenia, supraventricular tachycardia, congenital adrenal hyperplasia, and cystic fibrosis. Among these approved small-molecule drugs, those with unique mechanisms of action and designated as breakthrough therapies by the FDA represent a significant proportion, highlighting ongoing innovation. Notably, eight of these drugs (including Rezdiffra®, Voydeya®, Iqirvo®, Voranigo®, Livdelzi®, Miplyffa®, Revuforj®, and Crenessity®) are classified as "first-in-class" and have received breakthrough therapy designation. These agents not only exhibit distinct mechanisms of action but also offer substantial improvements in efficacy for patients compared to prior therapeutic options. This article offers a comprehensive analysis of the mechanisms of action, clinical trials, drug design, and synthetic methodologies related to representative drugs, aiming to provide crucial insights for future pharmaceutical development.

AIE-active Cyclen-BODIPYs as multiresponsive fluorescent probes for imaging in biological samples: Design and comprehensive study

The aggregation-induced emission (AIE) effect opens up new opportunities and prospects for the development of organic light-emitting materials. By exploiting the intrinsic ability of boron-dipyrromethenes (BODIPYs) to form aggregates, we rationally designed water-soluble AIE-active dyes derived from BODIPY fluorophores by their modification with azamacrocyclic units. The most AIE-active cyclen-BODIPY derivatives 5a and 8a showed high fluorescence quantum yields and they were found to be sensitive to water content, viscosity, pH, and temperature with a "turn-on" fluorescence response. The DLS and SEM results showed that these compounds exist as nanoscale aggregates in aqueous solutions. A possible molecular arrangement of dye 5a in aggregates was rationalized using TD-DFT calculations. The biologically relevant metal ions, such as Li+, K+, Na+, and Mg2+, have no pronounced effect on absorption and emission spectra of the dyes 5a and 8a. In vitro confocal microscopy studies in HeLa cells demonstrated that dyes 5a and 8a successfully permeated the cell membrane and selectively labeled lysosomes. These findings suggest that cyclen-BODIPY derivatives hold promise for investigating lysosomal dynamics and function in living cells via fluorescence imaging.

Investigation of Thiazolidine-2,4-Dione Derivatives as Acetylcholinesterase Inhibitors: Synthesis, In Vitro Biological Activities and In Silico Studies

The inhibition of acetylcholinesterase (AChE), an enzyme responsible for the inactivation and decrease in acetylcholine in the cholinergic pathway, has been considered an attractive target for small-molecule drug discovery in Alzheimer's disease (AD) therapy. In the present study, a series of TZD derivatives were designed, synthesized, and studied for drug likeness, blood-brain barrier (BBB) permeability, and adsorption, distribution, metabolism, excretion, and toxicity (ADMET). Additionally, docking studies of the designed compounds were performed on AChE. Additionally, all the TZD derivatives (CHT1-5) showed an acceptable affinity for AChE inhibition, and the results showed convincing binding modes in the active site of AChE. Among them, 5-(4-methoxybenzylidene) thiazolidine-2,4-dione (CHT1) was identified as the most potent AChE inhibitor (IC50 of 165.93 nM) with the highest antioxidant activity. Following the exposure of PC12 cells to Aβ1-42 (100 μM), a marked reduction in cell survival was observed. Pretreatment of PC12 cells with TZD derivatives had a neuroprotective effect and significantly enhanced cell survival in response to Aβ-induced toxicity. Western blotting analysis revealed that CHT1 (5 and 8 μM) downregulated p-Tau and HSP70 expression levels. The results indicate that CHT1 is a promising and effective AchE-I that could be utilized as a powerful candidate against AD.

Fungal mediated production of novel metabolites of meloxicam and their tankyrase-2 inhibition potentials: an in silico study

The current study focuses on the isolation of a thermophilic fungus capable of biotransforming meloxicam to produce novel metabolites with potential tankyrase inhibitory properties. The isolated strain is identified as Rhizomucor pusillus, confirmed through both morphological and molecular methodologies. The biotransformation process was monitored using high-performance liquid chromatography (HPLC) in conjunction with a two-stage fermentation approach. Previous research, along with LC-MS/MS analyses, has successfully characterized the metabolites generated, providing structural validation. This fungus enabled the conversion of meloxicam into four metabolites: 5-hydroxy methyl meloxicam (M1), 5-carboxy meloxicam (M2), and two previously unreported metabolites (M3 and M4), under controlled conditions of pH 6.0 and a temperature of 40 °C over a 3-day shaking culture period. The fungal strain R. pusillus has demonstrated the ability to generate notable metabolites of meloxicam, particularly M1 and M2, as evidenced by research conducted on mammals. Moreover, in silico analyses have revealed the presence of two novel metabolites that may inhibit tankyrase-2. This finding indicates that R. pusillus possesses an enzymatic system comparable to that found in mammals, facilitating the environmentally sustainable and economically viable production of metabolites. Additionally, this strain is capable of synthesizing substantial amounts of metabolites that could potentially exhibit pharmacological effects.

One-Pot Multicomponent Synthesis of Fully Substituted 1,3-Thiazoles Appended with Naturally Occurring Lawsone

Lawsone is a popular bioactive natural product. 1,3-Thiazoles are also widely distributed in many natural products, FDA-approved drugs, and functional materials. We report herein the first synthesis of naturally occurring lawsone-linked fully substituted 1,3-thiazoles in a one-pot multicomponent reaction (MCR) of arylglyoxals, lawsone, and thiobenzamides in acetic acid at 90 °C, affording lawsone-1,3-thiazole hybrids in excellent yields in short reaction times. The advantages of the present method include facile, robust, and easy access to the medicinally relevant diverse array of fully substituted lawsone-1,3-thiazole hybrids, easy isolation of the product by filtration, thereby avoiding column-chromatographic purifications, short reaction time, and metal- and catalyst-free and gram-scale synthesis.

Low-energy electron driven reactions in 2-bromo-5-nitrothiazole

Thiazole derivatives are biologically relevant molecules, used also in pharmaceutical applications. Herein, we report results for electron attachment to 2-bromo-5-nitrothiazole (BNT) in the gas phase. Employing two crossed electron-molecule beam experiments, we determined the efficiency curves of various fragment anions as a function of the initial electron energy between about 0 and 10 eV as well as the emission angle and kinetic energy distributions of Br- and NO2- ions formed from a resonance near 4 eV. The experiments were supported by quantum chemical calculations, exploring possible dissociation pathways along with their reaction energies. We also compared the electron attachment characteristics of BNT with those of the native thiazole molecule by performing electron attachment experiments and calculations for this molecule as well. Compared to thiazole, which is primarily degraded only by electrons with kinetic energies between about 5 and 10 eV, BNT is susceptible to low-energy electrons near 0 eV with enhanced cross section for (dissociative) electron attachment. However, although BNT offers two localization sites with high electron affinity (Br and NO2 moieties), we do not find the corresponding anions as the dominant negatively charged species formed upon electron attachment. Instead, the reaction channels with an abstraction of Br and NO2 as neutral radicals prevail, accompanied by the opening of the thiazole ring due to the relatively weak C-S bond.

Visible-Light-Induced Annulation of Benzothioamides with Sulfoxonium Ylides To Construct Thiazole Derivatives

Herein, visible-light-induced annulation of benzothioamides with sulfoxonium ylides to furnish thiazole derivatives is developed under transition-metal-, photocatalyst-, and oxidant-free conditions. This protocol exhibits good substrate scope, affording the desired products with satisfied yields in a mild and green manner. Detailed mechanistic studies suggest that the benzothioamide substrate plays a dual role in this reaction. Under visible-light irradiation, excited benzothioamide, in its triplet state, could undergo S attack to the C═S moiety of the sulfoxonium ylide followed by the dissociation of dimethyl sulfoxide and H migration to give a key adduct. In addition, benzothioamide could act as an organocatalyst to facilitate the intramolecular cyclization of the adduct and proton transfer steps. After the dehydration of the cyclized intermediate, the desired thiazole derivatives can be produced.

Current antibiotics for leptospirosis: Are still effective?

Leptospirosis is a recurring zoonotic disease of global significance. Leptospirosis is curable, and antibiotics are available for its treatment. However, little is known about the effectiveness of the currently used antibiotics against different Leptospira species, serovars, and strains. This review aimed to give insight into the anti-leptospiral activities of the currently available antibiotics towards Leptospira strains and their effectiveness in treating and preventing leptospirosis. Anti-leptospiral activities from natural resources were also reviewed. The literature search was conducted using several databases. The majority of Leptospira strains were sensitive to the current antibiotics. Antibiotics can accelerate the defervescence and reduced the occurrence of leptospirosis cases, nevertheless, there is no affirmative evidence on the beneficial effects of the antibiotics compared to placebo in preventing death. Adverse reactions like Jarisch-Herxheimer reactions (JHR) in patients treated with the current antibiotics were also reported. Plants, marine actinobacteria and propolis are shown as potential sources of new anti-leptospiral compounds. Although leptospirosis can still be adequately treated with current antibiotics, continuous susceptibility testing and the development of novel antibiotics especially from natural resources are highly encouraged.

Thiazole and Isothiazole Chemistry in Crop Protection

Thiazole and isothiazole are types of five-membered heterocycles that contain both sulfur and nitrogen atoms. They have gained attention in the field of green pesticide research due to their low toxicity, strong biological activity, and ability to undergo diverse structural modifications. By incorporating thiazole and isothiazole groups into various compounds, researchers have been able to create a wide range of pesticides with broad-spectrum effectiveness. Understanding the relationship between the structure of these compounds and their activities is crucial for the development of new and highly potent pesticides. This review highlights thiazole and isothiazole derivatives with various biological activities and aims to inspire the development of innovative pesticide based on these structures.

The synthesis and antileukemic activity of 5-substituted thiazolyl urea derivatives

A series of novel 5-substituted thiazolyl urea derivatives were synthesized and evaluated for their efficacy as antileukemic agents against two human leukemic cell lines (THP-1 and MV-4-11). Results showed that the activities of the investigated compounds were quite sensitive to the positions and properties of the aromatic substituents. Among these compounds, compound 12k showed the highest activity with IC50 values of 29 ± 0.3 nM for THP-1 cells and 98 ± 10 nM for MV-4-11 cells.

Thiazole-fused androstenone and ethisterone derivatives: potent β- and γ-actin cytoskeleton inhibitors to treat melanoma tumors

Melanoma, the most fatal form of skin cancer, often becomes resistant to the current therapeutic approaches in most patients. To explore new treatment options, fused thiazole derivatives were synthesized, and several of these compounds demonstrated potent anti-melanoma activity both in vitro and in vivo. These compounds exhibited significant cytotoxicity against melanoma cell lines at low concentrations. The lead molecules induced apoptosis and caused G2/M phase cell cycle arrest to a lesser extent. These compounds also displayed remarkable antimetastatic activities in several cell-based and molecular assays, significantly inhibiting key processes of metastasis, such as cell migration and adhesion. mRNA sequencing revealed significant downregulation of β-actin (ACTB) and γ-actin (ACTG1) at the transcriptional level, and a similar effect was observed at the protein level by western immunoblotting and proteomics assays. Actin-rich membrane protrusions formation is crucial for facilitating metastasis by promoting cell migration. Fluorescence microscopy demonstrated that compounds E28 and E47 inhibited the formation of these membrane protrusions and impaired actin cytoskeleton dynamics. Docking studies suggested the lead compounds may suppress tumor proliferation and metastasis by targeting the mechanistic target of Rapamycin complex 2 (mTORC2). All these findings unanimously indicated the translational perspective of ethisterone and androstenone fused thiazole derivatives as potent antimetastatic and antimelanoma agents. In a preclinical mouse melanoma model, compounds E2 and E47 significantly reduced tumor growth and greatly improved overall mice survival, while showing a favorable safety profile based on a comprehensive blood plasma metabolite profile. These lead molecules also displayed promising physicochemical properties, making them strong candidates for further drug development studies.

Insight into the therapeutic potential of pyrazole-thiazole hybrids: A comprehensive review

Several pyrazole-thiazole hybrids featuring two potentially bioactive pharmacophores with or without linker have been synthesized using the molecular hybridization approach as target structures by medicinal chemists to modulate multiple drug targets simultaneously. The presented review aims to provide an overview of the diversified and wide array of pharmacological activities of these hybrids bestowing anticancer, antifungal, antibacterial, analgesic, anti-inflammatory, antioxidant, antitubercular, antiviral, antiparasitic, and miscellaneous activities. The structure-activity relationships and potential mechanism of action are also reviewed to shed light on the development of more effective and biotargeted candidates. This review focuses on the latest research advances in the biological profile of pyrazole-thiazole hybrids reported from 2015 to the present, providing medicinal researchers with a comprehensive platform to rationally design and develop more promising pyrazole-thiazole hybrids.

Immobilization of Thermomyces lanuginosus lipase on metal-organic frameworks and investigation of their catalytic properties and stability

Surface adsorption is a convenient and readily available method for immobilizing enzymes on metal-organic frameworks (MOFs). Metal-organic framework-5 (MOF-5), isoreticular metal-organic frameworks-3 (IRMOF-3), and multivariate analysis of MOF-5/IRMOF-3 (MMI) with a half-amino group (-NH2) were prepared in this study. Thermomyces lanuginosus lipase (TLL) was chosen as a commercially available enzyme for immobilization on the surfaces of these MOFs. Briefly, 1.5 mg of TLL was added to 10 mg of the MOFs, and after 24 h, 67, 74, and 88% of the TLL was immobilized on MOF-5, IRMOF-3, and MMI, respectively. Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, energy-dispersive X-ray analysis, and Brunauer-Emmett-Teller analysis were used to characterize the resulting biocomposites. TLL@MOF-5, TLL@IRMOF-3, and TLL@MMI exhibited activities of 55, 75, and 110 U/mg, respectively. Investigation of the activity and stability of the prepared biocatalysts showed that TLL immobilized on MMI was 2.34-fold more active than free TLL. TLL@MMI exhibited high stability and activity even under harsh conditions. After 24 h of incubation in a mixture of 50% (v/v) MeOH, TLL@MMI retained 80% of its activity, whereas TLL@MOF-5 and free TLL lost 50 and 60% of their activities, respectively. TLL@MMI was used to synthesize 2-arylidenehydrazinyl-4-arylthiozole derivatives (91-98%) in a one-pot vessel by adding benzaldehydes, phenacyl bromides, and thiosemicarbazide to water. The efficiency of the 4a derivative with free TLL was 43%, whereas that with TLL@MMI was 98%.

Structure-Activity Relationship of Hydrazinylthiazole-5-Carbaldehydes as Potential Anti-Diabetic Agents

Diabetes is an emerging threat to the world due to large number of deaths reported within the last decade. To overcome its spread and complications, herein, we reported synthesis and anti-diabetic potential of twelve novel 2-[(arylidenyl)methylidene]hydrazinyl-1,3-thiazole-5-carbaldehydes (3 a-l). All compounds have shown good to excellent α-amylase inhibitory activity, among them ortho substituted analogues, the compound 3 a (IC50=14.6 mM) and 3 l (IC50=17.9 mM) showed excellent inhibition potential due to the strong electron donating nature of the substituents attached at the aryl ring. The compounds 3 a-3 h (IC50=6.70-10.80 ppm) exhibited excellent anti-glycation potential as compared to standard amino-guanidine (IC50=11.92 ppm). Almost all the tested compounds are found biocompatible and very safe to the human erythrocyte cells at all tested concentrations. The molecular docking results have found that the binding energy score of all the tested compounds against human serum albumin protein (pdb: 1AO6) is between -5.1827 and -6.8661 kcal/mol which is far better than standard amino-guanidine (-4.234 kcal/mol).

Eco-friendly Regioselective Synthesis, Biological Evaluation of Some New 5-acylfunctionalized 2-(1H-pyrazol-1-yl)thiazoles as Potential Antimicrobial and Anthelmintic Agents

The present study describes an eco-friendly NBS-assisted regioselective synthesis of new 5-acylfunctionalized 5-acylfunctionalized 2-(1H-pyrazol-1-yl)thiazoles by condensation of 3,5-dimethyl-1H-pyrazole-1-carbothioamide with unsymmetrical 1,3-diketones under solvent-free conditions. The structural elucidation of the newly synthesized compounds was accomplished using various spectroscopic techniques viz. FTIR, NMR and mass spectrometry. All the newly synthesized compounds were examined for their in vitro antimicrobial potential against both pathogenic gram positive and gram negative bacterial and fungal species as well as anthelmintic activity against Pheretima posthuma earthworms. The results of antimicrobial activity revealed that all tested compounds 3 a-j showed excellent antimicrobial potential particularly against S. aureus. It was also observed that compounds 3 e and 3 i (MIC=62.5 μg/mL) showed greater potency against E. coli, whereas compounds 3 a and 3 h (MIC=50 μg/mL and 62.5 μg/mL) demonstrated better activity against P. aeruginosa and compound 3 i (MIC=62.5 μg/mL) exhibited superior activity against S. pyogenus when compared to standard drug Ampicillin (MIC=100μg/mL). Compound 3 e and 3 j revealed remarkable antifungal and anthelmintic activities. To find out binding interactions of target compounds with target proteins and pharmacokinetic parameters of the compounds, in silico investigations involving molecular docking studies and ADMET predictions were also performed.

Development of potential cathepsin B inhibitors: Synthesis of new bithiazole derivatives, in vitro studies supported with theoretical docking studies

Cysteine cathepsins play a crucial role in cancer, inflammation, and the regulation of degenerative processes such as apoptosis, making them significant targets in drug development. In this study, we designed, synthesized, and characterized sixteen novel bi-thiazole derivatives, confirmed by 1H NMR, 13C NMR, HRMS, and X-ray analysis, which demonstrated significant therapeutic potential as inhibitors of cathepsin B. The synthesized thiazoles showed % inhibition in the range of 59.11-77.32, out of which bis-methoxyphenyl derivative 8k showed the highest inhibition of 77.32 % with IC50 and ki values of 1.04 nM and 0.52 nM, respectively. Methoxy-containing derivatives 8c, 8g, 8i, 8j, 8l, and 8o showed improved inhibition over methyl and chloro. In silico studies of the new bis-thiazole compounds at cathepsin B active sites supported the in vitro findings, indicating that the synthesized bis-thiazole esters are promising therapeutic candidates for conditions involving elevated cathepsin B levels.

Synthesis of hydroxy-thiazoline substituted pyridine derivatives via [3 + 2] annulation of 1,4-dithiane-2,5-diol with cyanopyridine

A series of hydroxy-thiazoline substituted pyridine compounds were synthesized via the annulation of 1,4-dithiane-2,5-diol with cyanopyridine catalyzed by organic bases. The yields could reach up to 95%. The reaction required no solvent, and the products were obtained from raw materials and catalysts simply by grinding the mixture at room temperature for 10 min. The reaction could be well tolerated by variously substituted cyanide compounds. The universal applicability of this method was proven by gram-scale reaction and product derivatization.

Clinical pharmacokinetics of cefpodoxime: a systematic review

INTRODUCTION

Cefpodoxime, a third-generation cephalosporin, is a broad-spectrum antibiotic widely used to treat acute upper respiratory tract infections (RTI). This systematic review aims to present a comprehensive view of all the available pharmacokinetics (PK) data associated with the pharmacodynamics (PD) parameters of cefpodoxime in humans.

AREAS COVERED

The PubMed, Google Scholar, Cochrane Library, and Science Direct, were systematically searched to identify studies on the PK of cefpodoxime. Out of 746 papers, 26 articles meeting the eligibility criteria were included that have reported the PK data. The drug exposure for the patients undergoing hemodialysis was 50% lower than healthy participants. The renal clearance was almost 27% less in pediatric patients than in adults. The plasma concentrations of cefpodoxime exceeded the minimum inhibitory concentration (MIC) for 90% of skin pathogens, including Streptococcus species and Staphylococcus species (i.e.) < 1 μg/mL and 2-4 μg/mL respectively.

EXPERT OPINION

The current study includes detailed information on clinical PK of cefpodoxime in healthy, diseased, pediatric populations as well as drug-drug interactions and drug-food interactions. Moreover, this systematic review also explicated PK/PD properties of drug with a specific impact on MIC of drug. The present review will also assist clinicians in the development of PK models for cefpodoxime.

Novel thiazole-based cyanoacrylamide derivatives: DNA cleavage, DNA/BSA binding properties and their anticancer behaviour against colon and breast cancer cells

A novel series of 2-cyano-3-(pyrazol-4-yl)-N-(thiazol-2-yl)acrylamide derivatives (3a-f) were synthesized using Knoevenagel condensation and characterized using various spectral tools. The weak nuclease activity of compounds (3a-f) against pBR322 plasmid DNA was greatly enhanced by irradiation at 365 nm. Compounds 3b and 3c, incorporating thienyl and pyridyl moieties, respectively, exhibited the utmost nuclease activity in degrading pBR322 plasmid DNA through singlet oxygen and superoxide free radicals' species. Furthermore, compounds 3b and 3c affinities towards calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were investigated using UV-Vis and fluorescence spectroscopic analysis. They revealed good binding characteristics towards CT-DNA with Kb values of 6.68 × 104 M-1 and 1.19 × 104 M-1 for 3b and 3c, respectively. In addition, compounds 3b and 3c ability to release free radicals on radiation were targeted to be used as cytotoxic compounds in vitro for colon (HCT116) and breast cancer (MDA-MB-231) cells. A significant reduction in the cell viability on illumination at 365 nm was observed, with IC50 values of 23 and 25 µM against HCT116 cells, and 30 and 9 µM against MDA-MB-231 cells for compounds 3b and 3c, respectively. In conclusion, compounds 3b and 3c exhibited remarkable DNA cleavage and cytotoxic activity on illumination at 365 nm which might be associated with free radicals' production in addition to having a good affinity for interacting with CT-DNA and BSA.

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

A series of new RS-, RS-CH2- and R2N-CH2-functionalized сatechols with heterocyclic fragments such as 1,3,4-oxadiazole, 1,2,4-triazole, thiazole, or pyridine were synthesized by the reaction of 3,5-di-tert-butyl-o-benzoquinone or 3,5-di-tert-butyl-6-methoxymethylcatechol with different heterocyclic thiols. The S-functionalized catechols were prepared by the Michael reaction from 3,5-di-tert-butyl-o-benzoquinone and the corresponding thiols. The starting reagents such as substituted 1,3,4-oxadiazole-2-thiols and 4H-triazole-3-thiols are characterized by thiol-thione tautomerism, therefore their reactions with 3,5-di-tert-butyl-6-methoxymethylcatechol can proceed at the sulfur or nitrogen atom. In the case of mercapto-derivatives of thiazole or pyridine, this process leads to the formation of the corresponding thioethers with a methylene linker. At the same time, thiolated 1,3,4-oxadiazole or 1,2,4-triazole undergo alkylation at the nitrogen atom in the reaction with 3,5-di-tert-butyl-6-methoxymethylcatechol to form the corresponding thiones. The yield of reaction products ranges from 42 to 80%. The crystal structures of catechols with 3-nitropyridine or 1,3,4-oxadiazole-2(3H)-thione moieties were established by single-crystal X-ray analysis. The possibility of forming intra- and intermolecular hydrogen bonds has been established for these compounds. The electrochemical behavior of the studied compounds is influenced by several factors: the nature of the heterocycle and its substituents, the presence of a sulfur atom in the catechol ring, or a thione group in the heterocyclic core. The radical scavenging activity and antioxidant properties were determined using the reaction with synthetic radicals, the cupric reducing antioxidant capacity assay, the inhibition process of superoxide radical anion formation by xanthine oxidase, and the process of lipid peroxidation of rat liver (Wistar) homogenates in vitro.

An Insight into Rational Drug Design: The Development of In-House Azole Compounds with Antimicrobial Activity

Antimicrobial resistance poses a major threat to global health as the number of efficient antimicrobials decreases and the number of resistant pathogens rises. Our research group has been actively involved in the design of novel antimicrobial drugs. The blueprints of these compounds were azolic heterocycles, particularly thiazole. Starting with oxadiazolines, our research group explored, one by one, the other five-membered heterocycles, developing more or less potent compounds. An overview of this research activity conducted by our research group allowed us to observe an evolution in the methodology used (from inhibition zone diameters to minimal inhibitory concentrations and antibiofilm potential determination) correlated with the design of azole compounds based on results obtained from molecular modeling. The purpose of this review is to present the development of in-house azole compounds with antimicrobial activity, designed over the years by this research group from the departments of Pharmaceutical and Therapeutical Chemistry in Cluj-Napoca.

An Update on the Nitrogen Heterocycle Compositions and Properties of U.S. FDA-Approved Pharmaceuticals (2013-2023)

This Perspective is a continuation of our analysis of U.S. FDA-approved small-molecule drugs (1938-2012) containing nitrogen heterocycles. In this study we report drug structure and property analyses of 321 unique new small-molecule drugs approved from January 2013 to December 2023 as well as information about frequency of important heteroatoms such as sulfur and fluorine and key small nitrogen substituents (CN and NO2). The most notable change is an incredible increase in drugs containing at least one nitrogen heterocycle─82%, compared to 59% from preceding decades─as well as a significant increase in the number of nitrogen heterocycles per drug. Pyridine has claimed the #1 high-frequency nitrogen heterocycle occurrence spot from piperidine (#2), with pyrimidine (#5), pyrazole (#6), and morpholine (#9) being the big top 10 climbers. Also notable is high number of fused nitrogen heterocycles, apparently driven largely by newly approved cancer drugs.

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.

Regiodivergent C-H alkynylation of 2-arylthiazoles switched by RuII and PdII catalysis

Two complementary regiodivergent C-H alkynylations of 2-arylthiazoles are reported. When RuII catalysis is employed, an aryl ortho-alkynylation process is favored. The alkynylated products are gained in good yields. With the use of PdII catalysis, a thiazole C5-alkynylation process is developed, allowing for the construction of C5-alkynylated products. This strategy not only expands the methods for the functionalization of 2-arylthiazoles, but also provides new opportunities for the rapid assembly of complex molecular structures, which may have great potential in organic synthesis, medicinal chemistry, and materials science.

Design, Synthesis, Biological Evaluation, and Molecular Docking Studies of Pleuromutilin Derivatives Containing Thiazole

In this study, we designed and synthesized a series of pleuromutilin derivatives containing thiazole. The in vitro antimicrobial efficacy of these synthesized compounds was examined by using four strains. Compared with tiamulin (MIC = 0.25 μg/mL), compound 14 exhibited potency in inhibiting MRSA growth (MIC = 0.0625 μg/mL) in these derivatives. Meanwhile, the time-killing kinetics further demonstrated that compound 14 could efficiently inhibit the MRSA growth. After exposure at 4 × MIC, the postantibiotic effect (PAE) of compound 14 was 1.29 h. Additionally, in thigh-infected mice, compound 14 exhibited a more potent antibacterial efficacy (-1.78 ± 0.28 log10 CFU/g) in reducing MRSA load compared to tiamulin (-1.21 ± 0.23 log10 CFU/g). Moreover, the MTT assay on RAW 264.7 cells demonstrated that compound 14 (8 μg/mL) had no significant cytotoxicity. Docking studies indicated the strong affinity of compound 14 toward the 50S ribosomal subunit, with a binding free energy of -9.63 kcal/mol. Taken together, it could be deduced that compound 14 was a promising candidate for treating MRSA infections.

Synthesis of new N-(5,6-methylenedioxybenzothiazole-2-yl)-2-[(substituted)thio/piperazine]acetamide/propanamide derivatives and evaluation of their AChE, BChE, and BACE-1 inhibitory activities

In this study, the synthesis of N-(5,6-methylenedioxybenzothiazole-2-yl)-2-[(substituted)thio/piperazine]acetamide/propanamide derivatives (3a-3k) and to investigate their acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and β-secretase 1 (BACE-1) inhibition activity were aimed. Mass, 1H NMR, and 13C NMR spectra were utilized to determine the structure of the synthesized compounds. Compounds 3b, 3c, 3f, and 3j showed AChE inhibitory activity which compound 3c (IC50 = 0.030 ± 0.001 µM) showed AChE inhibitory activity as high as the reference drug donepezil (IC50 = 0.0201 ± 0.0010 µM). Conversely, none of the compounds showed BChE activity. Compounds 3c and 3j showed the highest BACE-1 inhibitory activity and IC50 value was found as 0.119 ± 0.004 µM for compound 3j whereas IC50 value was 0.110 ± 0.005 µM for donepezil, which is one of the reference substance. Molecular docking studies have been carried out using the data retrieved from the server of the Protein Data Bank (PDBID: 4EY7 and 2ZJM). Using in silico approach behavior active compounds (3c and 3j) and their binding modes clarified.

Novel hybrid thiazoles, bis-thiazoles linked to azo-sulfamethoxazole: Synthesis, docking, and antimicrobial activity

The reaction of sulfamethoxazolehydrazonoyl chloride with thiosemicarbazones, bis-thiosemicarbazones, or 4-amino-3-mercapto-1,2,4-triazole in dioxane in the presence of triethylamine as a basic catalyst at reflux resulted in the regioselective synthesis of thiazoles and bis-thiazoles linked to azo-sulfamethoxazole as novel hybrid molecules. The structures of the new compounds were confirmed using a range of spectra. Each compound's antibacterial properties were evaluated using the agar well-diffusion technique, and most of them demonstrated significant potency. In silico investigations revealed that the described compounds had strong interactions with the binding sites of MurE ligase, tyrosyl-tRNA synthetase, and dihydropteroate synthase, demonstrating inhibitory activity.

Three-Component Assembly of Dihydropyrrolo[3,4-e][1,3]thiazines from Elemental Sulfur, Maleimides, and 1,3,5-Triazinanes

A three-component reaction for the synthesis of dihydropyrrolo[3,4-e][1,3]thiazines has been developed. Elemental sulfur, maleimides, and 1,3,5-triazinanes are assembled together through sulfuration/nucleophilic attack in N-methylpyrrolidin-2-one (NMP) under mild conditions. A small amount of NaHCO3 is important for the activation of the reaction. In this method, sulfur plays a dual role in thiazine ring formation, while triazinanes are utilized as three-atom synthons in the annulation reaction.

A Review of FDA-Approved Anti-HIV-1 Drugs, Anti-Gag Compounds, and Potential Strategies for HIV-1 Eradication

Acquired immunodeficiency syndrome (AIDS) is an enormous global health threat stemming from human immunodeficiency virus (HIV-1) infection. Up to now, the tremendous advances in combination antiretroviral therapy (cART) have shifted HIV-1 infection from a fatal illness into a manageable chronic disorder. However, the presence of latent reservoirs, the multifaceted nature of HIV-1, drug resistance, severe off-target effects, poor adherence, and high cost restrict the efficacy of current cART targeting the distinct stages of the virus life cycle. Therefore, there is an unmet need for the discovery of new therapeutics that not only bypass the limitations of the current therapy but also protect the body's health at the same time. The main goal for complete HIV-1 eradication is purging latently infected cells from patients' bodies. A potential strategy called "lock-in and apoptosis" targets the budding phase of the life cycle of the virus and leads to susceptibility to apoptosis of HIV-1 infected cells for the elimination of HIV-1 reservoirs and, ultimately, for complete eradication. The current work intends to present the main advantages and disadvantages of United States Food and Drug Administration (FDA)-approved anti-HIV-1 drugs as well as plausible strategies for the design and development of more anti-HIV-1 compounds with better potency, favorable pharmacokinetic profiles, and improved safety issues.

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.

Visible-Light-Driven Deoxygenative Heteroarylation of Alcohols with Heteroaryl Sulfones

The visible-light-promoted deoxygenative radical heteroarylation of alcohols was achieved in the absence of any external photosensitizers. The processes occur through the generation of xanthate salts from alcohols, followed by SET and fragmentation, delivering alkyl radicals to react with heteroaryl sulfones. This method is amenable for a wide range of alcohols with good functional group tolerance, providing a practical strategy for the alkylation of benzo-heteroaromatics. Mechanism studies indicate that direct visible-light excitation of xanthate anions and subsequent SET initiate the reactions.

Investigating Novel Thiophene Carbaldehyde Based Thiazole Derivatives as Potential Hits for Diabetic Management: Synthesis, In Vitro and In Silico Approach

This research work is based on synthesis of eleven novel thiazole derivatives (3 a‐k) of thiophene carbaldehyde. All the synthesized compounds were successfully synthesized, characterized by 1H‐NMR and EI‐MS spectroscopic techniques and finally subjected for their in vitro α‐glucosidase inhibitory activity. Seven derivatives 3 i (IC50=10.21±1.84 μM), 3 b (IC50=11.14±0.99 μM), 3 f (IC50=13.21±2.76 μM), 3 h (IC50=14.21±0.31 μM), 3 k (IC50=15.21±1.02 μM), 3 e (IC50=16.21±1.32 μM), and 3 c (IC50=18.21±1.89 μM), in the series displayed excellent inhibitory potential better than the standard acarbose. However, two compounds 3 g (IC50=33.21±1.99 μM) and 3 d (IC50=42.31±2.12 μM) showed significant activity while two compounds 3 j and 3 a were found less active with IC50 values of 82.31±0.31 and 88.36±1.21 μM respectively. Additional research revealed that the compounds are not exhibiting any cytotoxic effects. The molecular docking study of these derivatives showed their good binding potential for α‐glucosidase active site with excellent interactions and docking scores.

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.

New thiazolyl-isoxazole derivatives as potential anti-infective agents: design, synthesis, in vitro and in silico antimicrobial efficacy

Antimicrobial resistance threatens the efficacious prevention and treatment of infectious diseases caused by microorganisms. To combat microbial infections, the need for new drug candidates is essential. In this context, the design, synthesis, antimicrobial screening, and in silico study of a new series of 5-aryl-3-(2-arylthiazol-4-yl)isoxazole (9a-t) have been reported. The structure of new compounds was confirmed by spectrometric methods. Compounds 9a-t were evaluated for in vitro antitubercular and antimicrobial activity. Against M. tuberculosis H37Rv, fourteen compounds showed good to excellent antitubercular activity with MIC 2.01-9.80 µM. Compounds 9a, 9b, and 9r showed four-fold more activity than the reference drug isoniazid. Nine compounds, 9a, 9b, 9d, 9e, 9i, 9q, 9r, 9s, and 9t, showed good antibacterial activity against E. coli with MIC 7.8-15.62 µg/mL. Against A. niger, four compounds showed good activity with MIC 31.25 µg/mL. Against C. albicans, all twenty compounds reported excellent to good activity with MIC 7.8-31.25 µg/mL. Compounds 9c-e, 9g-j, and 9q-t showed comparable activity concerning the reference drug fluconazole. The compounds 9a-t were screened for cytotoxicity against 3t3l1 cell lines and found to be less or non-cytotoxic. The in silico study exposed that these compounds displayed high affinity towards the M. tuberculosis targets PanK, DprE1, DHFR, PknA, KasA, and Pks13, and C. albicans targets NMT, CYP51, and CS. The compound 9r was evaluated for structural dynamics and molecular dynamics simulations. The potent antitubercular and antimicrobial activity of 5-aryl-3-(2-arylthiazol-4-yl)isoxazole (9a-t) derivatives has recommended that these compounds could assist in treating microbial infections.

Approaches Towards Better Immunosuppressive Agents

Several classes of compounds are applied in clinics due to their immunosuppressive properties in transplantology and the treatment of autoimmune diseases. Derivatives of mycophenolic acid, corticosteroids and chemotherapeutics bearing heterocyclic moieties like methotrexate, azathioprine, mizoribine, and ruxolitinib are active substances with investigated mechanisms of action. However, improved synthetic approaches of known drugs and novel derivatives are still being reported to attempt better accessibility and therapeutic properties. In this review article, we present the synthesis of the designed chemical structures based on recent literature reports concerning novel compounds as promising immunosuppressive drugs. Moreover, some of the discussed derivers revealed also other types of activities with prospective medicinal potential.

Thiazole-based analogues as potential antibacterial agents against methicillin-resistant Staphylococcus aureus (MRSA) and their SAR elucidation

In recent years, the overuse of antibiotics has resulted in the emergence of antibiotic resistance, which is a serious global health problem. Methicillin-resistant Staphylococcus aureus (MRSA) is a common and virulent bacterium in clinical practice. Numerous researchers have focused on developing new candidate drugs that are effective, less toxic, and can overcome MRSA resistance. Thiazole derivatives have been found to exhibit antibacterial activity against drug-sensitive and drug-resistant pathogens. By hybridizing thiazole with other antibacterial pharmacophores, it is possible to obtain more effective antibacterial candidate drugs. Thiazole derivatives have shown potential in developing new drugs that can overcome drug resistance, reduce toxicity, and improve pharmacokinetic characteristics. This article reviews the recent progress of thiazole compounds as potential antibacterial compounds and examines the structure-activity relationship (SAR) in various directions. It covers articles published from 2018 to 2023, providing a comprehensive platform to plan and develop new thiazole-based small MRSA growth inhibitors with minimal side effects.

Green Synthesis and Molecular Docking Study of Some New Thiazoles Using Terephthalohydrazide Chitosan Hydrogel as Ecofriendly Biopolymeric Catalyst

Terephthalohydrazide chitosan hydrogel (TCs) was prepared and investigated as an ecofriendly biopolymeric catalyst for synthesis of some novel thiazole and thiadiazole derivatives. Thus, TCs was used as a promising ecofriendly basic biocatalyst for preparation of three new series of thiazoles and two thiadiazoles derivatives via reacting 2-(2-oxo-1,2-diphenylethylidene) hydrazine-1-carbothio-amide with various hydrazonoyl chlorides and α-haloketones under mild ultrasonic irradiation. Also, their yield% was estimated using chitosan and TCs in a comparative study. The procedure being employed has the advantages of mild reaction conditions, quick reaction durations, and high reaction yields. It also benefits from the catalyst’s capacity to be reused several times without significantly losing potency. The chemical structures of the newly prepared compounds were confirmed by IR, MS, and 1H-NMR. Docking analyses of the synthesized compounds’ binding modes revealed promising binding scores against the various amino acids of the selected protein (PDB Code—1JIJ). SwissADME’s online tool is then used to analyze the physiochemical and pharmacokinetic characteristics of the most significant substances. The majority of novel compounds showed zero violation from Lipinski’s rule (Ro5).

Evaluation of Anti-Inflammatory and Anti-Tubercular Activity of 4-Methyl-7-Substituted Coumarin Hybrids and Their Structure Activity Relationships

Four sets of previously synthesized 4-methyl-7-substituted coumarin derivatives were screened for their in vitro anti-inflammatory and anti-tubercular activities. The anti-inflammatory potential of 3a-t, 5a-o, 6a-n, and 7a-f synthesized compounds was evaluated by an anti-denaturation assay using diclofenac sodium as the reference standard. Evaluation of the anti-tuberculous activity of the mentioned compounds was performed by the Resazurin test method against four different TB strains using rifampicin and isoniazid as reference drugs. Based on the anti-inflammatory results, compounds 3o, 5f, 6c, and 7d proved to be the most active compounds in their respective series. Additionally, compounds 3k-n, 5b-d, 6d-f, 6k, 7a, and 7f were found to be the most potent anti-tuberculous agents. In fact, most of the screened compounds exhibited promising activity profiles compared to the respective standard drugs. The structure-activity connections revealed a few intriguing aspects, indicating that the presence of electron-donating and nitrogen-rich fragments boost the anti-inflammatory effects of the examined compounds. However, the presence of electron-withdrawing substituents was required to boost the anti-tubercular activity of the evaluated compounds.

In vitro activity, ultrastructural analysis and in silico pharmacokinetic properties (ADMET) of thiazole compounds against adult worms of Schistosoma mansoni

The present work aimed to carry out in vitro biological assays of thiazole compounds against adult worms of Schistosoma mansoni, as well as the in silico determination of pharmacokinetic parameters to predict the oral bioavailability of these compounds. In addition to presenting moderate to low cytotoxicity against mammalian cells, thiazole compounds are not considered hemolytic. All compounds were initially tested at concentrations ranging from 200 to 6.25 μM against adult worms of S. mansoni parasites. The results showed the best activity of PBT2 and PBT5 at a concentration of 200 μM, which caused 100% mortality after 3 h of incubation. While at 6 h of exposure, 100% mortality was observed at the concentration of 100 µM. Subsequent studies with these same compounds allowed classifying PBT5, PBT2, PBT6 and PBT3 compounds, which were considered active and PBT1 and PBT4 compounds, which were considered inactive. In the ultrastructural analysis the compounds PBT2 and PBT5 (200 µM) promoted integumentary changes with exposure of the muscles, formation of integumentary blisters, integuments with abnormal morphology and destruction of tubercles and spicules. Therefore, the compounds PBT2 and PBT5 are promising antiparasitics against S. mansoni.

Rediscovering Cyanogen Gas for Organic Synthesis: Formation of 2-Cyanothiazole Derivatives

The expeditious synthesis of an API building block, 2-cyanothiazole, from cyanogen gas and a readily available dithiane is reported. A previously undisclosed partially saturated intermediate is formed, which can be further functionalized and isolated by the acylation of the hydroxy group. Dehydration using trimethylsilyl chloride furnished 2-cyanothiazole, which could be further converted to the corresponding amidine. The sequence provided a 55% yield over 4 steps. We envision that this work will spark further interest in cyanogen gas as a reactive and cost-effective synthetic reagent.

Natural Products as the Potential to Improve Alzheimer's and Parkinson's Disease

Alzheimer's disease and Parkinson's disease are the two most common neurodegenerative diseases in the world, and their incidence rates are increasing as our society ages. This creates a significant social and economic burden. Although the exact cause and treatment methods for these diseases are not yet known, research suggests that Alzheimer's disease is caused by amyloid precursor protein, while α-synuclein acts as a causative agent in Parkinson's disease. The accumulation of abnormal proteins such as these can lead to symptoms such as loss of protein homeostasis, mitochondrial dysfunction, and neuroinflammation, which ultimately result in the death of nerve cells and the progression of neurodegenerative diseases. The medications currently available for these diseases only delay their progression and have many adverse effects, which has led to increased interest in developing natural products with fewer adverse effects. In this study, we selected specific keywords and thesis content to investigate natural products that are effective in treating Alzheimer's and Parkinson's diseases. We reviewed 16 papers on natural products and found that they showed promising mechanisms of action such as antioxidant, anti-inflammatory, and mitochondrial function improvement. Other natural products with similar properties could also be considered potential treatments for neurodegenerative diseases, and they can be consumed as part of a healthy diet rather than as medicine.

Thiazolyl hydrazineylidenyl indolones as unique potential multitargeting broad-spectrum antimicrobial agents

The emergence of pathogenic and drug-resistant microorganisms seriously threatens public safety. This work constructed a unique type of thiazolyl hydrazineylidenyl indolones (THIs) to combat global microbial multidrug-resistance. Bioactive evaluation discovered that some target THIs displayed much superior antimicrobial efficacy than clinical chloromycetin, norfloxacin, cefdinir or fluconazole against the tested strains. Eminently, butyl THI 6c displayed a broad antimicrobial spectrum with low MICs of 0.25-1 μg/mL. The highly active THI 6c not only showed low cytotoxicity and hemolysis, rapidly bactericidal ability, good antibiofilm activity and promising pharmacokinetic properties, but also could significantly impede the development of bacterial resistance. Preliminary exploration of antibacterial mechanism revealed that THI 6c could effectively penetrate the cell membrane of MRSA and embed DNA to form 6c‒DNA supramolecular complex and thus hinder DNA replication. Moreover, THI 6c could reduce cell metabolic activity, which might be attributed to the fact that THI 6c could target the pyruvate kinase of MRSA and interfere with the function of the enzyme. These results provided powerful information for further developing thiazolyl hydrazineylidenyl indolones as new broad-spectrum antimicrobial agents.