Bridge control of photophysical properties in benzothiazole-phenoxazine emitters – from thermally activated delayed fluorescence to room temperature phosphorescence

The bridging phenyl group in a fluorescent phenoxazine-benzothiazole donor-acceptor dyad is replaced by either a naphthalene or a thiophene moiety to probe the influence of a more extended conjugated system...

Thiophene and its Analogs as Prospective Antioxidant Agents: A Retrospect

: The field of Free Radical Chemistry has gained considerable interest in the current scenario. The formation of free radicals is attributable to different physiochemical factors, radiation exposure, pathological conditions, environmental contaminants, and as by-products of metabolized drugs. The concentration of free radicals is regulated strongly under normal conditions by physiological antioxidants. Free radicals may cause oxidative damage to proteins, lipids, sugars, and DNA when abundantly produced or when antioxidants are depleted. This imbalance of reduction-oxidation, referred to as oxidative stress, can change the body's physiological conditions and ultimately lead to tissue injury, further contributing to various disease pathologies. A proper balance between free radicals and antioxidants is required for an effective physiological process. The oxidation mechanism is chemically hindered by antioxidants; these are often called free radical scavengers. The application of an external antioxidant source is crucial in addressing the issue of oxidative stress. Plenty of naturally occurring, semi-synthetic, and synthetic antioxidants are used, and the search for an efficient, non-toxic, and safe antioxidant is stepped up over time. As an influential scaffold, thiophene and its derivatives have become a significant source of interest for researchers due to its substantial variety of biological activities. The versatility of thiophene moiety has been identified by an affluent unveiling of its derivatives with anti-inflammatory, antioxidant, anti-cancer, and antimicrobial behaviors. Thiophene activity has been influenced greatly by the nature and orientation of the substitutions. The current study aims at addressing various synthetic compounds with thiophene or condensed thiophene as a fundamental moiety or substituent as radical scavengers.

Facile Synthesis, Characterization and in Silico Docking Studies of Novel Thiazolidine-2,4-Dione-Based Mannich Base Bearing Furan/Thiophene Moiety as Promising Anti-Inflammatory Agents

Mannich bases are compounds bearing a β-amino carbonyl moiety. They are formed in the Mannich reaction that consists of an amino alkylation of an acidic proton placed next to a carbonyl functional group by formaldehyde and a primary or secondary amine. Mannich base products are known for their curative properties such as anti-inflammatory, antibacterial, anticancer, antifungal, anthelmintic, anticonvulsant, analgesic, anti-HIV, antipsychotic, antiviral, and antimalarial activities. Further, thiazolidinedione derivatives have shown to be efficacious in inflammatory diseases as wide-ranging as psoriasis, ulcerative colitis and non-alcoholic steatohepatitis. In light of the above observations, new series of thiazolidine-2,4-dione based Mannich base derivatives were synthesized via a simple and catalyst-free procedure involving the condensation of thiazolidine-2,4-dione, formaldehyde and secondary amines in DMF solvent. The structures of the newly synthesized compounds were confirmed by their IR, 1H-NMR, and Mass spectra. The synthesized compounds were tested for their in silico anti-inflammatory activity by Docking studies against COX-2 enzyme (PDB: 1CX2). Compounds 4a and 4b showed good in silico anti-inflammatory properties comparable to that of standard drug Diclofenac and may be considered as promising candidates for the development of new anti-inflammatory agents.

Intelligent Consensus Predictions of Biodegradation Half-Life of Petroleum Hydrocarbons (PHCs)

The present study explores the important chemical features of diverse petroleum hydrocarbons (PHCs) responsible for their biodegradation by developing partial least squares (PLS) regression-based quantitative structure-property relationship (QSPR) models. The biodegradability is estimated in terms of biodegradation half-life (Logt1/2). All the PLS models were extensively validated by different internationally acceptable internal (R2= 0.849–0.861; Q2 = 0.833–0.849; R2adj = 0.845–0.858) and external (Q2F1= 0.825-0.848; Q2F2 = 0.822–0.845) validation parameters. The consensus predictions were also performed by using the “intelligent consensus predictor” (ICP) tool, which improves the predictive ability of individual models based on mean absolute error (MAE)-based criteria. The models suggested that the biodegradation of PHCs is dependent on the presence of substituents on the aromatic ring, 12 atom containing ring system, thiophene moiety, electron rich chemicals, large molecular size, degree of unsaturation, degree of branching, cyclization, and hydrophobicity.

Synthesis, characterization, and performance of oligothiophene cyanoacrylic acid derivatives for solar cell applications

New dye sensitizers based on an oligothiophene cyanoacrylic acid derivative were synthesized and characterized for solar cell applications. The structures of the new dyes prepared as sensitizers based on oligothiophenes, namely5,5''-di-2-cyanoacrylic acid [2,2':5',2''-terthiophene] (dye1), [2,2':5',2''-terthiophene]-5-cyanoacrylic acid(dye2), and [2,2':5',2'':5'',2'''-quaterthiophene]-5-cyanoacrylic acid(dye3) were confirmed by elemental analysis, mass spectrometry, and 1H-NMR spectral data. The P3HT/dye2/nc-TiO2 solar cell produced the highest efficiency of 0.05% with an open circuit voltage of 0.65V compared to dyes 1 and 3 solar cells. That may have been attributed to the dyes’ molecular structure, which had different chain lengths and numbers of groups of cyanoacrylic connected to the dyes’ thiophene moiety The dark current suppressed in the P3HT/dye2/nc-TiO2 solar cells indicated the formation of the charge blocking layer, which produced an enhanced open-circuit voltage accompanied by a high onset voltage.

Synthesis, optical, photophysical and solvatochromoic properties on the D-π-A dye with benzo[b]thiophene moiety

A D-π-A solvatochromic chromophore based on the novel benzo[b]thiophene moiety donor, the tricyanofuran (TCF) acceptor, alkoxy chains modified aniline and extended π-conjugations have been synthesized and systematically investigated in this paper. The absorption and fluorescence emission spectra of the dye in different polar solvents were studied. A positive solvatochromism of the dye was observed also with a color change of the solution that could be observed with the naked eye. The HOMO and LUMO values of the dye was obtained by both cyclic voltammetry and theoretical calculations. By adding acid/base into the DMSO solution of the dye, the color, absorption and fluorescence emission spectra of the solution showed the good characteristics of pH switch, which has potential applications for the molecular sensors and probe.

Chimeric Drug Design with a Noncharged Carrier for Mitochondrial Delivery

Recently, it was proposed that the thiophene ring is capable of promoting mitochondrial accumulation when linked to fluorescent markers. As a noncharged group, thiophene presents several advantages from a synthetic point of view, making it easier to incorporate such a side moiety into different molecules. Herein, we confirm the general applicability of the thiophene group as a mitochondrial carrier for drugs and fluorescent markers based on a new concept of nonprotonable, noncharged transporter. We implemented this concept in a medicinal chemistry application by developing an antitumor, metabolic chimeric drug based on the pyruvate dehydrogenase kinase (PDHK) inhibitor dichloroacetate (DCA). The promising features of the thiophene moiety as a noncharged carrier for targeting mitochondria may represent a starting point for the design of new metabolism-targeting drugs.

Synthesis and optical properties of new 4-substituted pyrimidines - D-A type chromophores

The set of 4-aryl(hetaryl)pyrimidines, where aryl/hetaryl is a highly electron donating substituent was synthesized. Optical and electrochemical properties of the synthesized compounds were studied and the values of a forbidden band gap energy ( ) were determined. The narrowest bandgap was found to be inherent to 4-ferrocenylpyrimidine (1.8 eV) and the most long-wavelength emission maximum ‑ to para-substituted pyrimidine which structure embeds a thiophene moiety between N-hexylcarbazolyl fragment and the pyrimidine core (577 нм).

A Review on Anticancer Activities of Thiophene and Its Analogs

Cancer is the world's second-largest cause of mortality and one of the biggest global health concerns. The prevalence and mortality rates of cancer remain high despite significant progress in cancer therapy. The search for more effective, as well as less toxic treatment methods for cancer, is at the focus of current studies. Thiophene and its derivatives have surged as an influential scaffold, which, because of their appreciable diversity in biological activities, has drawn the concerned interest of the researchers in the field of medicinal chemistry. By the affluent introduction of its derivatives, which have antioxidant, anti-inflammatory, antimicrobial, and anticancer activities, the adaptability of the thiophene moiety has been displayed. The nature and positioning of the substitutions significantly impacted thiophene moiety activity. This decent array in the living response account about this moiety has picked plentiful researcher’s consideration to inquire about it to its peculiar potential across certain activities. In the field of cancer therapy against different cancer cells, the structure-activity relationship for each of the derivatives showed an excellent understanding of thiophene moiety. Information from the various articles revealed the key role of thiophene moiety and its derivatives to develop the vital lead compound. The essential anticancer mechanisms identified include inhibition of the topoisomerase, inhibition of tyrosine kinase, tubulin interaction and apoptosis induction through the activation of reactive oxygen species. This review is an endeavor to promote the anticancer potential of the derivatives, whether having thiophene or condensed thiophene as a core moiety or as a substituent that can lead in the future to synthesize varieties of chemotherapeutic entities in the field of cancer treatment.

Chimeric Drug Design with a Noncharged Carrier for Mitochondrial Delivery

Recently, it was proposed that the thiophene ring is capable of promoting mitochondrial accumulation when linked to fluorescent markers. As a noncharged group, thiophene presents several advantages from a synthetic point of view, making it easier to incorporate such a side moiety into different molecules. Herein, we confirm the general applicability of thiophene group as mitochondrial carrier for drugs and fluorescent markers, based on a new concept of nonprotonable, noncharged transporters. We implemented this concept in a medicinal chemistry application by developing an anti-tumoral, metabolic chimeric drug, based on PDHK inhibitor dichloroacetate (DCA). The promising features of the thiophene moiety as a noncharged carrier for targeting mitochondria may represent a starting point for the design of new metabolism-aimed drugs.