Indirect Friedländer Reaction: From Transfer Hydrogenation to Acceptorless Dehydrogenative Coupling and Metal-Free Approaches.

The Friedländer quinoline synthesis represents a fundamental method for the construction of quinoline derivatives, a versatile class of heterocyclic compounds widely prevalent in pharmaceuticals and materials science. This synthesis traditionally involves the condensation of 2-aminoaryl ketones with carbonyl compounds, typically ketones or aldehydes, in the presence of an acid or base under reflux conditions. However, recent advancements have highlighted indirect approaches (starting from 2-aminobenzyl alcohol) to achieve the same quinoline framework, offering distinct advantages in selectivity, substrate scope, and functional group tolerance.

Targeting Alzheimer's pathology: Tetralone- and thiochromanone-based benzyl pyridinium derivatives as promising multi-target-directed ligands.

The lack of therapeutics that can fully halt the progression of Alzheimer's disease (AD) has prompted us to design and synthesize a series of tetralone/thiochromanone-based benzyl pyridinium salts (4a-4s) aimed at modulating multiple pathological targets associated with AD. Preliminary screening for cholinesterase and monoamine oxidase inhibition identified compounds 4e and 4g as the most potent inhibitors (AChE IC₅₀: 2.17 ± 0.

van der Waals pressure assisted synthesis of solid state nanomercury from mercury salts under ambient conditions: a sustainable approach for effortless Hg(II) removal from wastewater and safe storage thereof.

The synthesis and characterisation of stable solid mercury nanoparticles (HgNPs) face significant hurdles, as the physical properties of the material under ambient conditions limit the fabrication and characterisation of the element in the nanoregime. Extremely stringent conditions (1.2 GPa or -38 °C) are mandatory for achieving mercury in the solid state.

Critical validation of a GC-MS/MS methodology for confirmatory quantification of dioxins and PCBs in fish/ fish oil: Integrating a tiered surveillance strategy.

Dioxins and polychlorinated biphenyls (PCBs) are toxic, bioaccumulative persistent organic pollutants (POPs) requiring sensitive analysis in critical matrices, such as fish and fish products, to meet stringent regulatory standards. This study introduces a cost-effective complement to high-resolution mass spectrometry through a refined gas chromatography-tandem mass spectrometry workflow. The methodology integrates streamlined sample preparation, validation under European Union, 2017, and comprehensive measurement uncertainty estimation.

Harnessing coconut shell waste: Innovative utilization of activated carbon for effective quantification and decontamination of dioxins in fish oil.

Effective management of dioxins and polychlorinated biphenyls (PCBs) in food/feed matrices demands widespread surveillance and innovative decontamination strategies. This study investigates a cost-effective approach using coconut shell-based activated carbon (AC) as an efficient sorbent for two key applications: (i) facilitating the fractionation of dioxins and PCBs during routine analysis to improve surveillance and (ii) decontaminating these pollutants from feed-grade fish oil. The developed AC exhibited enhanced textural characteristics, transitioning from mesoporous to predominantly microporous structure.

Observation of Molecular Complexes in Oligo-Phenylenevinylene (OPV) Organogels by Neutron Diffraction.

In an earlier report, we conjectured that oligo-phenylenevinylene (OPV) molecules bearing terminal OH groups may form molecular complexes in organogels prepared in benzyl alcohol. This assumption was based on circumstantial evidence only. In this paper, we report on new experimental evidence by means of neutron diffraction that unambiguously demonstrates this conjecture.

Lyophilized ash gourd ( (Thunb.) Cogn.) juice alleviates diet-induced prediabetes in a rat model.

Prediabetes is characterized by elevated blood sugar levels, indicating an increased risk of developing diabetes. This study evaluated the effects of ash gourd (AG), a tropical fruit from the Cucurbitaceae family, on prediabetes, as well as its phytochemical composition. A prediabetic rat model was developed in Sprague-Dawley (SD) rats by administering a high fat diet (HFD) for 16 weeks.

Nanochitin: Green nanomaterial for sustainable applications in agriculture and environmental remediation.

The need for a green and sustainable nanomaterial sourced from biomass in the form of nanochitin has raised interest in paving the way towards incorporating biological resources for the production of functional materials. Nanochitin as nanofibers and nanocrystals/whiskers have attractive features like their ability to self-assemble into multidimensional biomaterials while retaining their intrinsic characteristics. Herein, the review discusses chitin's molecular association and hierarchical assemblies and gives an overview of the extraction methods adopted to produce nanochitin.

Bicyclic nucleoside analogues: synthesis of thiazolopyrimidine-based nucleosides a copper-catalysed tandem reaction of 5-iodocytidine with isothiocyanates.

We have devised a copper-catalysed tandem annulation reaction to generate a new class of bicyclic nucleoside analogues (BCNAs), namely, amino-substituted thiazolopyrimidine ribonucleosides. The reaction between triacetyl-5-iodo-cytidine and an appropriate organic isothiocyanate in the presence of a Cu salt and ligand resulted in the formation of an amino-substituted thiazolopyrimidine moiety. This reaction was found to be compatible with a range of aliphatic and aromatic isothiocyanates, affording the corresponding products in moderate to good yields.

Functionalization of Indoles with 1,3,5-Triazinanes: Chemistry of Aminomethylation vs the Hofmann-Martius-Type Rearrangement.

We have developed efficacious routes toward the selective synthesis of two classes of compounds such as C-3 amino-methylated indoles and 4-indol-3-yl-methylanilines from the same precursors, namely, indoles and 1,3,5-triazinanes. It is reported that the controlled cleavage of 1,3,5-triazinanes can be effected by heat for the generation of aryl imine motifs, and we observed that the presence of Lewis acid influences the course of these transformations toward different products. The reaction toward indol-3-yl-methylanilines proceeds via a nucleophilic attack of indole to the aryl imine generated from the 1,3,5-triazinanes to form an amino-methylated product which undergoes a Lewis acid mediated Hofmann-Martius-type rearrangement.

A Comprehensive Appraisal of Bisbenzylisoquinoline Alkaloids Isolated From Genus Cyclea for Anticancer Potential.

The pharmaceutical industry and academia are continuously searching for novel and effective anticancer lead compounds to ensure patient safety, provide a cure, and surpass all other obstacles. Given the indeterminate nature of cancer etiology, the importance of drugs capable of targeting multiple pathways cannot be overstated. Among naturally occurring compounds, bisbenzylisoquinoline (BBIQ) alkaloids, such as berberine, tetrandrine, chelidonine, and berbamine, have demonstrated significant anticancer potential by modulating diverse signaling pathways.

Synthesis of 2-hydroxy analogues of castanospermine, 1-epi-castanospermine and their iminooctitols from sugar-derived lactam.

The synthesis of 2-hydroxy analogues of castanospermine from two new iminooctitols via Mitsunobu cyclization is described. The iminooctitols were derived from the dihydroxylation of an allyl alcohol intermediate, obtained by adding vinylmagnesium bromide to the C6-aldehyde of a protected 1-deoxynojirimycin. An orthogonally protected hemiacetal with silyl group at the C6-hydroxy position and remaining as benzyl ethers, synthesized in four steps from d-glucose, served as a building block in the synthesis of the 1-deoxynojirimycin intermediate.

Distinguishing the Bimodal Interaction of a Squaraine Dye with a Protein by a Functional Group Photodeprotection Strategy.

In this study, we present a protecting group photocleavage method to investigate both covalent and noncovalent interactions between a squaraine dye (PSq) and Bovine Serum Albumin (BSA). This approach allows for the photoinduced activation and deactivation of PSq fluorescence, providing valuable insights into the dual-mode interaction of the dye with the protein.

Photonic Inks with Dual-Layer Security Features by Encapsulation of Color Tunable Fluorescent Dyes in PMMA Colloidal Microspheres.

To counter economic terrorism by preventing counterfeit currency, documents and high-value commercial products, new-generation security inks with multiple safety features are required. Herein, color-tunable pyrylium and pyridinium dye-encapsulated polymethyl methacrylate (PMMA) colloidal microspheres are reported to exhibiting brilliant emission and photonic properties. A combination of the PMMA colloidal photonic ink having structural color variation and the dye-encapsulated colloidal photonic ink with fluorescence modulation is used for security labeling.

Emerging alternative food protein sources: production process, quality parameters, and safety point of view.

The rise in the global population has increased the demand for dietary food protein. Strategies to maximize agricultural and livestock outputs could strain land and freshwater supply and contribute to substantial negative environmental impacts. Consequently, there has been an emphasis on identifying alternative sources of edible proteins that are more sustainable, sustainable, ethical, and healthy.

Correction: A comprehensive apoptotic assessment of niloticin in cervical cancer cells: a tirucallane-type triterpenoid from (Wall.) Parker.

[This corrects the article DOI: 10.1039/D4MD00318G.].