Dinitrogen Activation: A Novel Approach with P/B Intermolecular FLP.

This study explores the reactivity of a new intermolecular P/B frustrated Lewis pair in the context of dinitrogen activation through a push-pull mechanism. The ab initio molecular dynamics model known as atom-centered density matrix propagation plays a pivotal role in elucidating the weakly associated encounter complex. In-depth analysis, mainly through intrinsic reaction coordinate calculations, supports a single-step mechanism.

Submicromolar fluorescence 'turn-on' detection of fluoride anions using -(tetra-aryl) calix[4]pyrrole.

-(tetra-aryl) picket calix[4]pyrrole 1 featuring -fluorophenyl groups at all four -positions in a -configuration has been synthesized and characterized unambiguously using single-crystal X-ray diffraction analysis. This pre-organized system possesses a deep binding pocket created by the four aryl groups so that anions can be accommodated through anion-π interactions and four-point N-H⋯anion hydrogen bonds. Single-crystal X-ray diffraction analysis of the CsF and TEAF (TEA = tetraethylammonium) complexes of receptor 1 unequivocally confirms the formation of 1 : 1 complexes, revealing the binding modes in the solid state.

Landscaping DNA binding potential of piperine derivatives by computational and biophysical methods.

Piperine, the alkaloid from Black pepper, is known for its wide range of pharmacological effects. The DNA binding activity of piperine was reported earlier. In this work, we explore the DNA duplex binding properties of four piperine derivatives, piperonal, piperonyl alcohol, piperonylic acid, and piperic acid using biophysical and computational techniques.

A comparative study of titanium complexes bearing 2-(arylideneamino)phenolates and 2-((arylimino)methyl)phenolates as catalysts for ring-opening polymerization of ε-caprolactone and L-lactide.

Titanium complexes bearing 2-(arylideneamino)phenolates and 2-((arylimino)methyl)phenolates were synthesized, and their catalytic activities in the polymerization of ε-caprolactone and L-lactide were studied. Among five-membered ring Ti complexes bearing 2-(arylideneamino)phenolates, FCl-Ti exhibited the highest level of catalytic activity ([CL] : [FCl-Ti] = 100 : 1, where [CL] = 2 M, and conv. = 86% at 60 °C after 9 h).

An Integrated Polysaccharide Hydrogel with Versatile Fluorescence Responses through Noncovalent Reformation of Gel Aggregation and for Bioimaging.

Functionalized hydrogels, with their unique and adaptable structures, have attracted significant attention in materials and biomaterials research. Fluorescent hydrogels are particularly noteworthy for their sensing capabilities and ability to mimic cellular matrices, facilitating cell infiltration and tracking of drug delivery. Structural elucidation of hydrogels is crucial for understanding their responses to stimuli such as the pH, temperature, and solvents.

Ab initio investigation on the mechanism of SO activation by P/B intermolecular frustrated Lewis pairs.

Context: In silico study investigates the activation of sulfur dioxide by newly designed frustrated Lewis pairs, i.e., [P(Bu)…B(CNBSHF)], where the Lewis acid part is a super Lewis acid.

Design, synthesis, studies and apoptotic activity of novel amide enriched 2-(1)- quinazolinone derivatives.

Cancer is a broad classification of diseases that can affect any organ or body tissue due to aberrant cellular proliferation for unknown reasons. Many present chemotherapeutic drugs are highly toxic and have little selectivity. Additionally, they lead to the development of medication resistance.

Design, synthesis and in silico molecular docking evaluation of novel 1,2,3-triazole derivatives as potent antimicrobial agents.

Chalcone and triazole scaffolds have demonstrated a crucial role in the advancement of science and technology. Due to their significance, research has proceeded on the design and development of novel benzooxepine connected to 1,2,3-triazolyl chalcone structures. The new chalcone derivatives produced by benzooxepine triazole methyl ketone and different aromatic carbonyl compounds are discussed in this paper.

In Silico Investigation of the Mechanism of Disulfide Bond Dissociation by New Frustrated Lewis Pairs.

Understanding the mechanism of disulfide bond cleavage is important in various scientific disciplines including organic synthesis, catalysis, and biochemistry. In this study, an in silico investigation has been carried out for the dissociation of disulfide bonds using newly designed frustrated Lewis pairs (FLPs). The study revealed that the cleavage of the disulfide bond by the FLP P(Bu)/B(CNBSHF) can also be used like the conventional FLP (Bu)P/B(CF).

A liquid chromatography-tandem mass spectrometry method development for the quantification of favipiravir drug and its related impurities in rat plasma and its application to pharmacokinetic studies.

Favipiravir is an antiviral drug used for the treatment of virus-based diseases such as influenza. In this context, the development of a reliable liquid chromatography-tandem mass spectrometry method for the quantification of the drug and its impurities is necessary, particularly following the COVID-19 pandemic. Chromatographic separation was achieved on an inertial ODS column using gradient elution with a buffer containing triethylamine in high-performance liquid chromatography water and adjusting its pH with formic acid.

Interaction of gyrotactic moment of microorganisms and nanoparticles for magnetized and chemically reactive shear-thinning fluid with stratification phenomenon.

Nanotechnology has gained substantial attention on account of its vast applications in food manufacturing, heat exchanges, electronic cooling systems, medical treatment, coolant processes, energy production, biotechnology, transportation, biochemistry, nuclear reactors, and metrology. Currently, the phenomenon of bioconvection using nanomaterials has found wide industrial and technical implementations. Contemporary nanofluids are a dynamic source for illuminating heat transport systems related to engineering as well as industrial phenomena.

Identification, Synthesis, and Characterization of Potential Oxidative Impurities of Venetoclax: Application of Meisenheimer Rearrangement.

Venetoclax is a potent BCL-2 inhibitor that is used for the treatment of several blood cancers. During the oxidative stress degradation of venetoclax, we observed the formation of two potential impurities at levels of about 8-10%, which have similar molecular weights. The two impurities were isolated and identified as 4-(3-((1-pyrrolo[2,3-]pyridin-5-yl)oxy)-4-(((3-nitro-4-(((tetrahydro-2-pyran-4-yl)methyl)amino)phenyl)sulfonyl)carbamoyl)phenyl)-1-((4'-chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazine 1-oxide (venetoclax -oxide, ) and 2-((1-pyrrolo[2,3-]pyridin-5-yl)oxy)-4-(4-((4'-chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methoxy)piperazin-1-yl)--((3-nitro-4-(((tetrahydro-2-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax hydroxylamine impurity, ).

A new synthetic approach to cyclic ureas through carbonylation using di--butyl dicarbonate (boc anhydride) one pot strategy.

A new approach has been successfully employed to synthesize cyclic ureas carbonylation, utilizing Boc anhydride and employing KCO as a base along with ,-dimethylformamide as the solvent. Remarkably high yields were achieved using KCO in conjunction with (Boc)O, enabling the streamlined preparation of benzimidazolones and 2-benzoxazolones within a single reaction vessel. Significantly, this approach obviates the necessity for using any dangerous reagents, rendering it environmentally friendly, and its key benefit lies in being a metal-free system.

Insights into the catalytic activity of boron-doped thiazoles in the Diels-Alder reaction.

The role of boron-doped thiazoles as a Lewis acid catalyst in [4+2] cycloaddition reaction between 1,3-butadiene and acrolein has been addressed. Three different organic heterocycles were designed to study their catalytic activity. It has been observed that these heterocycles efficiently work as catalysts than the well-known Lewis acid BF.

Coconut coir-derived nanocellulose as an efficient adsorbent for removal of cationic dye safranin-O: a detailed mechanistic adsorption study.

Coconut (Cocos nucifera) coir is an abundant agricultural waste prevalent worldwide. Utilization of this waste has been carried out in this study by obtaining nanocellulose (NC) fibres for wastewater remediation purposes. Nanocellulose was obtained from coconut coir using bleaching and acid-alkali treatments followed by ultrasonication and lyophilization.

Concept-Driven Chemoselective O/N-Derivatization of Prolinol: A Bee-Line Approach to Access Organocatalysts.

An investigation into the sensitivity of reaction conditions to a highly utilized protocol has been reported, wherein the mono-Boc functionalization of prolinol could be controlled for the exclusive synthesis of either -Boc, -Boc, or oxazolidinone derivatives. Mechanistic investigation revealed that the elementary steps could possibly be controlled by (a) a requisite base to recognize the differently acidic sites (NH and OH) for the formation of the conjugate base, which reacts with the electrophile, and (b) the difference in nucleophilicity of the conjugate basic sites. Herein, a successful chemoselective functionalization of the nucleophilic sites of prolinol by employing a suitable base is reported.

A Highly Selective Schiff Base Based Chemodosimeter for the Detection of Perfluorooctanoic Acid by Optical Biosensor.

A simple imine derivative based sensor (IDP) has been synthesized and characterized by  H NMR,  C NMR and mass spectral techniques. IDP is more capable of detecting perfluorooctanoic acid (PFOA) in a selective and sensitive manner. The PFOA as a biomarker interacts with IDP and shows "TURN-ON" response by colorimetric and fluorimetric method.

Degradants of Tenofovir Disoproxil Fumarate Under Forced Yet Mild Thermal Stress: Isolation, Comprehensive Structural Elucidation, and Mechanism.

In addition to understanding the mechanism of action for a specific drug candidate, information regarding degradation pathways/products under various stress conditions is essential to know about their short- and long-term effects on health and environment. In line with that, tenofovir disoproxil fumarate (TDF, a co-crystal form of the prodrug tenofovir with fumaric acid), particularly used as an antiretroviral drug for treatment of HIV and hepatitis-B among others, is subjected to primarily thermal and other ICH-prescribed forced degradation conditions and their various degradation products are identified. Upon thermal degradation at 60°C for 8 h, five different degradants (namely DP-1 to DP-5) are isolated, and their structures are unambiguously confirmed using advanced analytical and spectroscopic techniques including ultra-performance liquid chromatography-mass spectrometry (UPLC-MS), high-resolution mass spectrometry (HRMS), state-of-the-art 1- and 2-dimensional nuclear magnetic resonance (1D and 2D NMR), and Fourier-transform infrared spectroscopic (FT-IR) techniques.

Xanthene-Separated 24 π-Electron Antiaromatic Rosarin Dimer.

Antiaromatic molecules have recently received attention because of their intrinsic properties, such as high reactivity and their narrow HOMO-LUMO gaps. Stacking of antiaromatic molecules has been predicted to induce three-dimensional aromaticity via frontier orbital interactions. Here, we report a covalently linked π-π stacked rosarin dimer that has been examined experimentally by steady-state absorption and transient absorption measurements and theoretically by quantum chemical calculations, including time-dependent density functional theory, anisotropy of induced current density, and nucleus-independent chemical shift calculations.

Synthesis and identification of new sacubitril derivatives as lead compounds for antibacterial, antifungal and antitubercular (TB) activities against dormant tuberculosis.

We identified twenty-two new sacubitril derivatives (5a-v) as lead compounds for various biologically active targets. These compounds were synthesized by reacting an intermediate compound (2,4)-5-([1,1'-biphenyl]-4-yl)-4-(amino)-2-methylpentanoic acid ethyl ester hydrochloride with respective carboxylic acid (RCOOH). The molecular structures of all the newly synthesized compounds were determined by H and C NMR, ESI mass spectrometry, FTIR spectroscopy, and CHN analysis.

Construction of Mechanically Interlocked Fluorescence Photoswitchable [2]Rotaxane with Aggregation-Induced Emission and Molecular Shuttling Behaviors.

Here, we report the design, synthesis, and optical behaviors of a multistimuli responsive [2]rotaxane system constructed from noncovalent interactions between diarylethene (DAE)-based axle and a tetraphenylethene (TPE)-based macrocycle using a snapping supramolecular assembly approach. The shuttling behavior of the macrocycle (-) between dialkylammonium and urea stations could be realized by the influence of acid-base stimuli using H NMR spectroscopy. Switching between the open-form (OF) [2]rotaxanes ( and ) is highly reversible using external chemical stimuli.

Identification, Synthesis, and Characterization of Novel Baricitinib Impurities.

Baricitinib is a novel active pharmaceutical ingredient used in the treatment of rheumatoid arthritis, and it acts as an inhibitor of Janus kinase. During the synthesis of baricitinib, three unknown impurities were identified in several batches between 0.10 and 0.

Analysis of Nonlinear Convection-Radiation in Chemically Reactive Oldroyd-B Nanoliquid Configured by a Stretching Surface with Robin Conditions: Applications in Nano-Coating Manufacturing.

Motivated by emerging high-temperature manufacturing processes deploying nano-polymeric coatings, the present study investigates nonlinear thermally radiative Oldroyd-B viscoelastic nanoliquid stagnant-point flow from a heated vertical stretching permeable surface. Robin (mixed derivative) conditions were utilized in order to better represent coating fabrication conditions. The nanoliquid analysis was based on Buongiorno's two-component model, which features Brownian movement and thermophoretic attributes.

Highly Sensitive and Selective Detection of Melatonin in Biofluids by Antipyrine Based Fluorophore.

A simple fluorescent based organic fluorophore was synthesized and it shows significant fluorescent intensity with melatonin (MLN). Hence, it was applicable to the detection of MLN by colorimetric and fluorimetric techniques at neutral pH. Under optimized experimental condition, the synthesized organic fluorophore detects MLN selectively in the presence of other interfering biomolecules through ICT mechanism.