Thiophene Motif Research Articles

Design, Synthesis, Characterization, Enzyme Inhibition, Molecular Docking, and Pharmacological Evaluation of New Chalcone‐Sulfonate Derivatives Bearing Thiophene

AbstractThe novel chalcone‐sulfonate derivatives bearing thiophene motif were synthesized and characterized using 1H NMR, 13C NMR, and HRMS analysis. The evaluation of in vitro and in silico potential pancreatic lipase inhibition activity of the novel chalcone‐sulfonate derivatives bearing thiophene motif was scanned. IC50 values of compounds 5 i (28.76±2.11 μM) and 5 f (30.58±0.45 μM) were determined to be more effective pancreatic lipase inhibitors for in vitro studies. The best potential inhibitor for pancreatic lipase binding affinity was found as compound 5 f (−9.8 kcal mol−1) for in silico studies. Although compounds 5 f and 5 i were identified as the best pancreatic lipase inhibitor candidates in vitro and molecular docking studies, compounds 5 f and 5 i were predicted mutagenic and carcinogenic properties in mice according to ADMET studies. Deeply, compound 5 h was a more effective pancreatic lipase inhibitor according to enzyme inhibition, molecular docking, and ADMET studies. It can be said that compound 5 h may be a more efficient drug candidate than orlistat in the treatment of obesity.

Catalytic asymmetric functionalization and dearomatization of thiophenes.

The asymmetric synthesis of thiophene-derived compounds, including catalytic asymmetric dearomatization of thiophene and atroposelective synthesis of benzothiophene derivatives, has rarely been reported. In this work, the asymmetric transformation of the thiophene motif is investigated. Through the rational design of substrates with a thiophene structure, by using the vinylidene ortho-quinone methide (VQM) intermediate as a versatile tool, axially chiral naphthyl-benzothiophene derivatives and thiophene-dearomatized chiral spiranes were obtained in high yields with excellent enantioselectivities.

C7‐Halomethylene/methyl‐C3‐thiophenyl‐spirocyclic‐β‐lactams: Synthesis, X‐ray Analysis, Antimicrobial Evaluation, Cytotoxicity Profile and Molecular Docking Interactions

AbstractIn the realm of healthcare, the continuous evolution of new alternative antimicrobial agents provides hope in addressing the progressively daunting issue of severe multidrug resistance. In our quest to confront drug resistance, we explored the conjugation of thiophene motif with β‐lactams into single matrix to develop a series of spirocyclic‐β‐lactams. For this, stereoselective synthesis of cis‐C3‐alkyloxy‐C4‐thiophenyl substituted monocyclic β‐lactams was achieved which were further subjected to intramolecular sulfenyl‐cyclization to furnish C7‐halomethylene/methyl‐C3‐thiophenyl substituted spirocyclic‐β‐lactams. The synthesized compounds were investigated in vitro for their potential activity against six multidrug‐resistant bacterial strains. The most promising C7‐iodomethylene‐C3‐thiophenyl‐spirocyclic‐β‐lactam 7 a appended with 4′‐methoxyphenyl moiety, exhibited acceptable activity against B. cereus and P. aeruginosa with MIC values of 0.75 and 6.25 μg/mL respectively, surpassing ampicillin and vancomycin. Furthermore, this compound demonstrated antifungal effectiveness against C. tropicalis (1.5 μg/mL). On the basis of substituent type and their respective positions, compounds possessing −OCH3 and −C=CHX (halomethylene) groups exhibited more inhibitory potential than others. Active derivatives tested for their cytotoxicity on normal human hepatic (THLE‐2) cell lines confirmed their non‐toxic nature. Further, molecular docking studies predicted the favourable binding interactions of spirocycles within active sites of target proteins. Moreover, several compounds illustrate satisfactory in silico ADME profile. These outcomes provided bright prospect for development of spirocyclic‐β‐lactams as potential solution to combat evolving multidrug resistance.

Binding and Transport Properties of a Benzo[b]thiophene‐Based Mono‐(thio)urea Library

AbstractUsing the chemical versatility of the benzo[b]thiophene motif, an extensive library of 24 (thio)urea receptors, with different binding properties and lipophilicities, was prepared and included α,α‐, α,β‐, β,β‐, β,γ‐, α,γ‐, and γ,γ‐benzo[b]thiophene positional isomers, as well as β‐ or γ‐benzo[b]thiophene‐based molecules decorated with aliphatic chains or aryl moieties with different fluorination degrees. 1H NMR titrations, X‐ray crystallographic studies, and DFT calculations were used to study the chloride binding affinities between receptors and substrates. Experimental efflux studies suggested that the anion transmembrane transport activity is dependent on the receptors′ lipophilicity and hydrogen bonding ability. Moreover, LUV based assays indicated that anion efflux occurs mainly through an uniport mechanism. Further MD simulations showed that anion transport is highly dependent on the orientation and interactions of the receptors at the water/lipid interface.

A highly active and selective chalcogen bond-mediated perchlorate channel

Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare. In this work, we report on one such novel monopeptide-based transporter system, featuring both chalcogen bonds for highly efficient anion transport and high transport selectivity toward ClO4− anions. Structurally, these monopeptide molecules associate with each other via H-bonds to produce H-bonded 1D stack that not only one dimensionally but also directionally aligns the terminal bicyclic thiophene motifs to the same side. Functionally, these well-aligned thiophenes create a sulfur-rich transmembrane pathway, combinatorially fine-tunable to enable anions to efficiently cross the membrane in the increasing activity of Cl− < Br− < NO3− < ClO4−via chalcogen bonds, with EC50 values of 0.75, 0.40, 0.37 and 0.093 µmol/L (0.3 mol% relative to lipid molecules), respectively.

Synthesis of a New Class of Spirooxindole-Benzo[b]Thiophene-Based Molecules as Acetylcholinesterase Inhibitors.

A series of new oxindole-based spiro-heterocycles bearing the benzo[b]thiophene motif were synthesized via a 1,3-dipolar cycloaddition reaction and their acetylcholinesterase (AChE) inhibitory activity was evaluated. All the synthesized compounds exhibited moderate inhibitory activities against AChE, while IIc was found to be the most active analog with an IC50 value of 20,840 µM·L−1. Its molecular structure was a 5-chloro-substituted oxindole bearing benzo[b]thiophene and octahydroindole moieties. Based on molecular docking studies, IIc was strongly bound to the catalytic and peripheral anionic sites of the protein through hydrophilic, hydrophobic, and π-stacking interactions with Asp74, Trp86, Tyr124, Ser125, Glu202, Ser203, Trp236, Trp286, Phe297, Tyr337, and Tyr341. These interactions also indicated that the multiplicity of the IIc aromatic core significantly favored its activity.

One-pot synthesis of thioxo-tetrahydropyrimidine derivatives as potent β-glucuronidase inhibitor, biological evaluation, molecular docking and molecular dynamics studies

A series of N,N-diethyl phenyl thioxo-tetrahydropyrimidine carboxamide have been synthesized and investigated for their β-glucuronidase inhibitory activities. All molecules exhibited excellent inhibition with IC50 values ranging from 0.35 to 42.05 µM and found to be even more potent than the standard d-saccharic acid. Structure-activity relationship analysis indicated that the meta-aryl-substituted derivatives significantly influenced β-glucuronidase inhibitory activities while the para-substitution counterpart outperforming moderate potency. The most potent compound in this series was 4g bearing thiophene motif with IC50 of 0.35 ± 0.09 µM. To verify the SAR, molecular docking and molecular dynamics studies were also performed.

Control of Chain Walking by Weak Neighboring Group Interactions in Unsymmetrical Catalysts.

A combined theoretical and experimental study shows how weak attractive interactions of a neighboring group can strongly promote chain walking and chain transfer. This accounts for the previously observed very different microstructures obtained in ethylene polymerization by [κ2-N,O-{2,6-(3',5'-R2C6H3)2C6H3-N═C(H)-(3,5-X,Y-2-O-C6H2)}NiCH3(pyridine)], namely hyperbranched oligomers for remote substituents R = CH3 versus high-molecular-weight polyethylene for R = CF3. From a full mechanistic consideration, the alkyl olefin complex with the growing chain cis to the salicylaldiminato oxygen donor is identified as the key species. Alternative to ethylene chain growth by insertion in this species, decoordination of the monomer to form a cis β-agostic complex provides an entry into branching and chain-transfer pathways. This release of monomer is promoted and made competitive by a weak η2-coordination of the distal aryl rings to the metal center, operative only for the case of sufficiently electron-rich aryls. This concept for controlling chain walking is underlined by catalysts with other weakly coordinating furan and thiophene motifs, which afford highly branched oligomers with >120 branches per 1000 carbon atoms.

Sulfur doped reduced graphene oxide as metal-free catalyst for the oxygen reduction reaction in anion and proton exchange fuel cells

Sulfur doped reduced graphene oxide (S-rGO) is investigated for catalytic activity towards the oxygen reduction reaction (ORR) in acidic and alkaline electrolytes. X-ray photoelectron spectroscopy shows that sulfur in S-rGO is predominantly integrated as thiophene motifs within graphene sheets. The overall sulfur content is determined to be approximately 2.2at.% (elemental analysis). The catalytic activity of S-rGO towards the ORR is investigated by both rotating disc electrode (RDE) and polymer electrolyte fuel cell (PEFC) measurements. RDE measurements reveal onset potentials of 0.3V and 0.74V (vs. RHE) in acidic and alkaline electrolyte, respectively. In a solid electrolyte fuel cell with S-rGO as cathode material, this is reflected in an open circuit voltage of 0.37V and 0.78V and a maximum power density of 1.19mW/cm2 and 2.38mW/cm2 in acidic and alkaline polymer electrolyte, respectively. This is the first report investigating the catalytic activity of a sulfur doped carbon material in both acidic and alkaline liquid electrolyte, as well as in both proton and anion exchange polymer electrolyte fuel cells.

Synthesis, optical, electrochemical properties and photovoltaic performance of novel panchromatic meso-thiophene BODIPY dyes with a variety of electron-donating groups at the 3,5-positions

A series of novel BODIPY derivatives (BDP1–5) containing a thiophene motif at the meso-position and various electron-donating units at the 3,5-positions were designed and synthesized.

Molecular and textural engineering of conjugated carbon nitride catalysts for selective oxidation of alcohols with visible light

A thiophene motif has been integrated into mesoporous carbon nitride (MCN) to improve the photoactivation of molecular oxygen towards the selective oxidation of alcohols. This modification also extends the photoactive part of the spectrum of MCN by electronic modification of the conjugated system.

Identification of the Significant Involvement and Mechanistic Role of CYP3A4/5 in Clopidogrel Bioactivation.

The clinical response to the antiplatelet prodrug clopidogrel is associated with high intersubject variability and a certain level of therapeutic resistance. Previous studies have suggested that genetic polymorphism of CYP2C19 might be one determinant of clopidogrel efficacy and led to the CYP2C19 genotype-tailored antithrombotic therapy. However, evidence against the role of CYP2C19 from multiple studies implied the involvement of other factors. Here, we report that prodrug activation of the thiophene motif in clopidogrel is attenuated by heavy metabolic attrition of the piperidine motif. CYP3A4/5 was identified to be the enzyme metabolizing the piperidine motif. Inhibiting CYP3A4/5-mediated attrition was shown to potentiate active metabolite formation, which was found to be catalyzed by multiple CYP enzymes. Identifying the significant involvement of CYP3A4/5 and characterizing its mechanistic role in clopidogrel bioactivation might assist future pharmacogenomic studies in exploring the full mechanism underlying clopidogrel efficacy.

Novel 5-(4-alkoxyphenyl)thieno[3,2-b]thiophene-2-carboxylate esters: Highly efficient synthesis and mesogenic evaluation of a new class of materials exhibiting the smectic C phase

A series of alkyl 5-(4-alkoxyphenyl)thieno[3,2-b]thiophene-2-carboxylates were prepared via a direct, efficient Pd(0)-catalysed Suzuki–Miyaura coupling approach. A series of long-chain alkyl thieno[3,2-b]thiophene-2-carboxylate esters, synthesised from newly reported alkyl mercaptoacetates, were elaborated into the target compounds via regioselective (C-5) halogenation followed by cross-coupling with 4-alkoxyphenyltrifluoroborate salts. As expected, these target alkyl 5-(4-alkoxyphenyl)thieno[3,2-b]thiophene-2-carboxylate ester mesogens exhibited the orthogonal smectic A phase; notably, they are the first materials built on the thieno[3,2-b]thiophene motif to also exhibit the smectic C mesophase.

A Novel and Expedient Approach to New Thiazoles, Thiazolo[3,2-a]pyridines, Dihydrothiophenes, and Hydrazones Incorporating Thieno[2,3-b]thiophene Moiety

This paper reports details about the synthesis of a series of novel functionalized symmetrical bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif. Bis-thiazole derivatives 2, 3a-c and thiazolo[3,2-a]pyridine derivatives 4a-c are achieved. The hitherto unknown dihydrothiophene derivatives 6a-d via bis-pyridimium salt 5 are obtained. Additionally, the novel hydrazonothieno[2,3-b]thiophene derivatives 10a-c are obtained via bis-tosylacetylthieno[2,3-b]thiophene derivative 9. All compounds are characterized by 1H-, 13C-NMR, GCMS, IR, and UV-vis spectrometry. These compounds represent a new class of sulfur and nitrogen containing heterocycles that should also be of interest as new materials.

Comprehensive and Facile Synthesis of Some Functionalized Bis-Heterocyclic Compounds Containing a Thieno[2,3-b]thiophene Motif

A comprehensive and facile method for the synthesis of new functionalized bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif is described. The hitherto unknown bis-pyrazolothieno[2,3-b]thiophene derivatives 2a–c, bis-pyridazin othieno[2,3-b]thiophene derivatives 4, bis-pyridinothieno[2,3-b]thiophene derivatives 6a,b, and to an analogous bis-pyridinothieno[2,3-b]thiophene nitrile derivatives 7 are obtained. Additionally, the novel bis-pyradazinonothieno[2,3-b]thiophene derivatives 9, and nicotinic acid derivatives 10, 11 are obtained via bis-dienamide 8. The structures of all newly synthesized compounds have been elucidated by 1H, 13C NMR, GCMS, and IR spectrometry. These compounds represent a new class of sulfur and Nitrogen containing heterocycles that should also be of interest as new materials.

Thiophene-based conjugated oligomers for organic solar cells

Owing to their efficient light harvesting, structural versatility and intrinsic charge transport behavior, thiophene-based π-conjugated systems have attracted much attention in developing high performance organic solar cells. In comparison to the relevant conjugated polymers that are used as active materials in photovoltaic devices, conjugated oligomers possess some critical advantages: (1) well-defined molecular structures lead to their synthetic reproducibility with high purity which is vital to obtain repeatable device performance; (2) crystalline features of oligomers favor the long range order in the solid state and benefit the charge carrier transport; (3) the devices can be readily fabricated by both solution-processable and vacuum-deposited techniques. In this feature article, thiophene-based conjugated oligomers with molecular architectures from 1D to 3D, which play an essential role in the device performance of organic solar cells, will be summarized. We aim to address the influence of the thiophene motifs on the electronic, optical and self-assembly properties of the materials, and eventually conclude the relationship between the molecular structures and photovoltaic properties.

Synthesis of functionalized hydroxy-thiophene motifs as amido- and sulfonamido-phenol bioisosteres

Novel highly substituted hydroxy thiophene motifs were designed and synthesized as viable amido phenol and sulfonamido phenol bioisosteres. Hydroxy group-directed regioselective bromination and palladium-catalyzed amination of thienyl bromide via Buckwald protocol are the key elements of the synthetic approach. The hydroxy thiophene-containing compounds displayed good binding inhibitions.