Nicotinamide (Nico) and derivatives of pyridine are important materials in both the pharmaceutical and agrochemical industries. In the 21st century, pyridine-based agrochemical products achieved commercial success because of their structural diversity and different modes of action that can be explored to improve the effectiveness of the compounds. In this article, we explore the cocrystallization of nicotinamide/isonicotinamide and substituted pyridines and their synthons to understand their ease of formation. A cocrystal of Nico and 2-chloro-3-hydroxypyridine (2Cl3OHPY) was synthesized using solution and mechanochemical methods, and characterized by X-ray diffraction. The structural stability and intermolecular interaction of the (Nico)·(2Cl3OHPY) cocrystal were investigated using differential scanning calorimetry (DSC) and density functional theory (DFT). The cocrystal has strong chain (N-H...N), dimer (N-H...O) and discrete (N-H...O) hydrogen bonds with energy strengths of -31.21, -66.99 and -36.82 kJ mol-1, respectively, and a short C-H...π bond that builds a twisted three-dimensional structure (viewed along the c axis) and stabilizes the crystal packing. The results show that the compound is chemically stable, and the two dominating interactions are electrostatic and dispersion energies. An analysis of the aromatic amide and pyridine synthon in the CSD reveals the presence of close supporting interactions that strengthen the N-H...N hydrogen bond. The understanding of the structural properties and intermolecular interactions in the (Nico)·(2Cl3OHPY) cocrystal and NH2...Npy synthon provided in this study could be used to design materials for different applications, including pigments, explosives, drugs, agrochemicals and food additives.

Caryota mitis Lour. is a tropical palm species traditionally used in folk medicine and considered a potential source of natural bioactive compounds. The present study aimed to investigate the phytochemical composition and antioxidant activity of the ethanolic fruit extract of Caryota mitis Lour. collected in Thai Nguyen province, Viet Nam. Qualitative phytochemical screening revealed the presence of several important secondary metabolites, including flavonoids, tannins, alkaloids, and saponins. The phytochemical profile of the extract was further analyzed using GC–MS, which tentatively identified more than 100 compounds belonging to different chemical groups such as flavonoids, lignans, alkaloids, steroids, ketones, and aromatic amides. Among the detected compounds, 3,3-Dimethoxy-2-butanone and 1-Butanamine were identified as major constituents. Several compounds with known biological activities, including flavonoid and phenolic derivatives, were also detected, suggesting potential pharmacological significance. The antioxidant activity of the extract was evaluated using the DPPH radical scavenging assay. The extract exhibited concentration-dependent antioxidant activity with considerable free radical scavenging capacity compared with vitamin C. The observed antioxidant potential may be associated with the synergistic effects of phenolic and flavonoid constituents present in the extract. These findings indicate that Caryota mitis Lour. fruits may serve as a promising natural source of bioactive compounds for pharmaceutical and functional food applications.

Chiral pesticides and herbicides (CPHs) show significant enantioselective differences in bioactivity, toxicity, and environmental behavior, making single-enantiomer production highly desirable for better efficacy and lower ecological risk. Among existing methods, lipase-catalyzed kinetic resolution is a more environmentally friendly alternative to chemical and chromatographic separations, as it has advantages of mild reaction conditions, low toxic and harmful byproducts, and excellent catalytic performance. Lipases have been broadly utilized for the production and processing of various CPHs, including organophosphorus pesticides, aryloxypropionate herbicides, pyrethroids, and aromatic amides. During the processing carried out through esterification, transesterification, and hydrolysis reactions, strategies such as solvent engineering, tailored reaction media, enzyme immobilization, and membrane-assisted processes can improve the catalytic efficiency, stereoselectivity, and stability. Artificial intelligence (AI)-assisted design of lipase, such as rational design, semirational design, and de novo design, will greatly change the prospects of enzyme engineering for the lipase-catalyzed enantioselective resolution of CPHs.

In the present study, novel amide derivatives of soybean oil fatty acids were synthesized via amidation of hydrolyzed fatty acids with aniline and benzylamine, yielding aromatic amides with structurally distinct amine moieties. These compounds were designed as potentially effective and biodegradable corrosion inhibitors. Comprehensive physicochemical characterization of the amides was performed using FT-IR and ¹H/¹³C NMR spectroscopy, while their thermal stability was assessed through thermogravimetric (TG) derivative thermogravimetric (DTG) and differential thermal analysis (DTA). The corrosion inhibition performance of the synthesized compounds was investigated using electrochemical techniques in CO₂-saturated 1 wt% NaCl solution. Linear polarization resistance (LPR) measurements were employed to study the time dependence of the corrosion rate, whereas potentiodynamic polarization (Tafel) curves were recorded to determine the electrochemical parameters of the corrosion process. The LPR results indicated that the inhibition efficiency of carbon steel increased with increasing inhibitor concentration, reaching 93-96% at 100 ppm. The inhibition mechanism was further elucidated by examining the surface morphology of mild steel using scanning electron microscopy (SEM). SEM images revealed that inhibitor-treated samples exhibited a smoother and less damaged surface compared to the uninhibited system, indicating the formation of a protective film. Adsorption behavior followed the Langmuir adsorption isotherm, and the calculated Gibbs free energy of adsorption (- 39 to - 42kJ mol⁻¹) suggested strong and spontaneous adsorption with a dominant chemisorption contribution. The antimicrobial activity of the compounds was evaluated against sulfate-reducing bacteria (Desulfovibrio desulfuricans) as well as Gram-negative bacteria (Escherichia coli and coliforms). The benzylamine-derived fatty acid amide demonstrated the highest activity, achieving complete inhibition of D. desulfuricans growth at 50mg L⁻¹. The results indicate that soybean oil fatty acid amides exhibit dual functionality, combining anticorrosive and antimicrobial properties, and may serve as promising environmentally friendly inhibitors for corrosion protection in oil-field environments affected by microbial activity.

Pyridone-fused aromatic belts, namely amide-bridged [6]cycloparaphenylenes, were successfully synthesized to investigate how polar amide groups govern symmetry and electronic structure in π-conjugated nanobelt molecules. The polar orientations of the six amide bonds give rise to two discrete structural isomers: S6- and D3-symmetric aromatic belts. These compounds were obtained through an efficient macrocyclization directed by the cis-preference of tertiary aromatic amides, followed by Ni-mediated intramolecular aryl-aryl coupling. Single-crystal x-ray diffraction analyses revealed that both isomers adopt rigid belt-shaped architectures with enhanced π-conjugation along the framework. The D3-symmetric isomer was successfully resolved into (M,M)- and (P,P)-enantiomers using chiral HPLC and the isomer exhibited a distinct chiroptical response in electronic circular dichroism spectroscopy (|gabs| = 2.7 × 10-3). Notably, cyclic voltammetry was used to demonstrate that the D3-symmetric isomer possesses a narrow HOMO-LUMO energy gap of 2.35eV together with considerably stabilized frontier molecular orbitals. This work establishes a versatile molecular design concept for constructing aromatic belts with well-defined chiroptical properties and high oxidative robustness, expanding opportunities in nanobelt science and chiral functional materials.

ABSTRACT Pyridone‐fused aromatic belts, namely amide‐bridged [6]cycloparaphenylenes, were successfully synthesized to investigate how polar amide groups govern symmetry and electronic structure in π‐conjugated nanobelt molecules. The polar orientations of the six amide bonds give rise to two discrete structural isomers: S 6 ‐ and D 3 ‐symmetric aromatic belts. These compounds were obtained through an efficient macrocyclization directed by the cis ‐preference of tertiary aromatic amides, followed by Ni‐mediated intramolecular aryl–aryl coupling. Single‐crystal x‐ray diffraction analyses revealed that both isomers adopt rigid belt‐shaped architectures with enhanced π‐conjugation along the framework. The D 3 ‐symmetric isomer was successfully resolved into ( M,M )‐ and ( P,P )‐enantiomers using chiral HPLC and the isomer exhibited a distinct chiroptical response in electronic circular dichroism spectroscopy (| g abs | = 2.7 × 10 −3 ). Notably, cyclic voltammetry was used to demonstrate that the D 3 ‐symmetric isomer possesses a narrow HOMO–LUMO energy gap of 2.35 eV together with considerably stabilized frontier molecular orbitals. This work establishes a versatile molecular design concept for constructing aromatic belts with well‐defined chiroptical properties and high oxidative robustness, expanding opportunities in nanobelt science and chiral functional materials.

Synthesis and biological activity evaluation of aromatic bisselenocyanate compounds.

To explore the contribution of the carboxylic group to the antiproliferative activity of 5-aminosalicylic-4-thiazolinone-based hybrids, multiple derivatives were synthesized, including free carboxylic, hydroxamic acid, and amidation with glycine or 2-amino-5-nitrothiazole. The antiproliferative activity of these derivatives was compared with that of methyl ester, aliphatic, and aromatic amides of the hybrid against eight cancer cell lines and one normal cell line using the sulforhodamine B (SRB) assay. Among the newly synthesized compounds, glycinate amide 9b exerted good to moderate antiproliferative activity against five cancer cell lines., It displayed superior activity against the Jurkat and Lymphoma cell lines with IC50 values of 4.74 µM and 7.16 µM, The overall results show that the methyl ester derivative of the hybrids is the most active among the tested derivatives against all tested cell lines with low micromolar to nanomolar potency. While hybrids with free or amidated carboxylic groups are much less potent. ADME study revealed that the difference in physicochemical properties might rationalize the activity pattern. This study demonstrates that the nature of the carboxylic group in these hybrids critically influences their antiproliferative activity. The findings pave the way for developing optimized anticancer salicylate drugs by focusing on modifications that improve key physicochemical properties.

Chiral propargylamines are a class of versatile building blocks in organic synthesis. Despite the recent breakthroughs on the catalytic asymmetric reductive alkynylation of amides to access propargylamines, a general protocol amenable to both aromatic and aliphatic tertiary amides remains elusive. Herein, we report that our recently developed methodology for the catalytic asymmetric reductive alkynylation of tertiary aliphatic amides can be extended to tertiary aromatic amides. Employing Vaska's complex/CuI/Carreira's (R,P)-PINAP ligand as the catalytic system and 1,1,3,3-tetramethyl-disiloxane (TMDS) as the hydrosilylation reagent, the method highlights good reagent economy and/ or excellent asymmetric induction as compared to the known ones. Moreover, the reductive alkynylation of tertiary aliphatic amides has been extended to a series of functionalized alkynes. It is expectable that the versatility, excellent functional group tolerance, and chemoselectivity of the method lay the foundation for diverse applications in organic synthesis and medicinal chemistry.

We report the first Ru(II)-catalyzed annulative linear dienylation reaction of aromatic amides with allenyl carbinol acetates. The protocol capitalizes on an oxidizing directing group and leverages regioselective 1,2-insertion of the allene motif to afford valuable 3-styrylisoquinolinones in high yields with exclusive trans-olefin geometry. It is operationally simple and scalable, features a wide substrate generality, and also remains effective in the presence of medicinally relevant scaffolds. The products can be further transformed into π-extended tetracyclic pyrano[2,3,4-gh]phenanthridines, which serve as efficient photocatalysts for reductive coupling reactions, as demonstrated by dehalogenative phenanthridinone formation and reductive pinacol coupling. DFT studies were carried out to elucidate the reaction mechanism and the origin of the observed selectivity.

The catalytic hydrogenation of amides continues to be one of the most difficult reductive transformations in organic synthesis. Despite significant efforts in past decades, there is no general protocol reported allowing the synthesis of various primary amines from the corresponding primary amides using molecular hydrogen. To perform this challenging reaction, here we report a specific homogeneous ruthenium catalyst based on the methoxy-substituted triphos ligand (Triphos(p-anisole)). In the presence of this Ru-catalyst system, industrially relevant, functionalized, and structurally diverse aromatic, heterocyclic and aliphatic primary amides including fatty amides have been selectively hydrogenated to produce the corresponding primary amines under comparably mild conditions (typically 115 °C and 10 bar H2). The resulting amines are valuable compounds with diverse applications in chemistry, medicine and biology as well as in materials and energy technologies.

General Background: Accurate differentiation between melanoma and basal cell carcinoma (BCC) is essential due to their distinct biological characteristics and clinical management. Specific Background: Raman spectroscopy enables label-free biochemical profiling of tissues by detecting molecular vibrations within the 600–1800 cm⁻¹ fingerprint region. Knowledge Gap: However, systematic discrimination between melanoma and BCC using fresh ex vivo Raman spectra remains limited. Aims: This exploratory study assessed the capability of Raman spectral fingerprints to distinguish melanoma from BCC using standardized preprocessing and statistical analysis. Results: Analysis of 40 spectra (20 melanoma, 20 BCC) acquired at 790 nm identified over 1000 statistically significant Raman shifts (FDR < 0.05), grouped into key biochemical bands related to aromatic amino acids, amide structures, and lipid vibrations. Major peaks at 748–755, 1000–1005, 1440–1455, and 1655–1665 cm⁻¹ showed large effect sizes. Principal component analysis demonstrated clear class separation, with PC1 explaining 61.5% of total variance. Novelty: The study defines distinct Raman spectral biomarkers differentiating melanoma and BCC through integrated statistical and multivariate approaches. Implications: These findings support Raman spectroscopy as a rapid molecular profiling tool for skin cancer subtyping and a basis for future clinical translation. Highlights:• Over 1000 Significant Raman Shifts Clustered Into Major Biochemical Bands Distinguishing Tumour Types.• Aromatic Amino Acids, Amide Structures, and Lipid Vibrations Exhibited Large Effect Sizes Between Groups.• Multivariate Modelling Showed Distinct Clustering With Dominant Variance Captured by the First Principal Component. Keywords: Raman Spectroscopy, Melanoma, Basal Cell Carcinoma, Skin Cancer Diagnostics, Spectral Biomarkers

Epidemiological studies indicate associations between exposures to endocrine-disrupting chemicals (EDCs) with reproductive disorders (e.g., early puberty). However, the scientific evidence remains limited, particularly in studies on clinically diagnosed precocious puberty (PP), and the specific pollutant drivers underlying this condition are poorly characterized. Identifying the key hazardous substances contributing to PP thus represents a critical research priority. This study conducted a population-based case–control study to profile the internal exposure to organic pollutants. Using a combination of liquid–liquid extraction (LLE) and solid-phase extraction, we performed suspect screening and nontargeted analysis with high-resolution mass spectrometry (HRMS) (liquid chromatography-/GC-Orbitrap HRMS). Nontargeted analysis revealed a broad spectrum of EDCs, including polycyclic aromatic hydrocarbons, phthalate esters (PAEs), organophosphate esters (OPEs), phenols, amides, and acrylates. Differential analysis between cases and controls further highlighted several pollutant classes, such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFAS), phenols, and chlorinated paraffins. These pollutants were significantly elevated in the PP group. These findings provide new internal exposure data and methodological support for environmental health research. They also offer a scientific foundation for targeted source–control strategies to reduce children’s exposure to harmful pollutants, supporting the broader public health objectives of “Healthy China 2030”.

Aromatic polyamide (PA) thin-film composite membranes are widely employed in reverse osmosis and nanofiltration for seawater desalination and water reuse. However, they can be degraded by chlorine used in water disinfection for biofouling control, hampering operational efficiency and the membrane service life. Tremendous efforts have been made to mitigate the adverse impacts of water disinfection on PA membranes while maintaining biofouling control and filtration performance. This paper reviews the reaction mechanisms of PA membranes with various disinfectants (e.g., chlorine, bromine, chlorine dioxide, monochloramine, peracetic acid, and hydrogen peroxide). Mechanisms for their reactions with the PA membrane model monomer (e.g., benzanilide) include aromatic substitution, N-substitution, and amide bond breakage. In general, disinfectants with a high reduction potential would cause severe membrane damage. An increase in the surface halogen content upon chlorine disinfection can decrease PA membrane hydrophilicity. Yet, degradation of the membrane via an oxidation pathway typically increases its hydrophilicity. Mild oxidation enhances membrane salt rejection because of increasing surface negative charge and tightening effects, while severe oxidation leads to a decline in membrane performance. While summarizing the state of knowledge on the PA membrane performance after water disinfection, this review also identifies several knowledge gaps to highlight future research topics of interest.

Benchmarking spectroscopic-chemometric models for human bloodstain time since deposition in tropical outdoor microenvironments.

The versatility of supramolecular chemistry stems from rational molecular design, which allows for the precise control over noncovalent interactions to direct self-assembly processes. Inspired by allosteric regulation in biomolecules, where long-range interactions dictate function, we report a novel aramide macrocyclic palladium complex that adopts distinct conformations upon allosteric complexation with ligands based on 4-substituted pyridine derivatives. Modulating ligand coordination strength and steric demand alters intramolecular three-center hydrogen-bond strength at a remote site, leading to inversion of the orientations of remote amide groups. This approach affords direct control over macrocyclic conformation in the solid state, allowing reversible transition between chairlike conformers with weakly coordinated ligands and V-shaped conformers with strongly coordinated ligands. Crucially, this conformational control, achieved through local binding events, i.e., atomic-level ligand exchange, while preserving the macrocyclic integrity, not only propagates to the supramolecular level but also sequentially modulates crystal packing, ultimately guiding the formation of higher-order structures driven by the precise columnar and layered arrangement of the palladium complex.

The present study reports the divergent reaction of previously underexplored arylglyoxyl radicals generated in situ from arylglyoxals in the presence of tert-butyl hydroperoxide (TBHP) and a catalytic amount of iodine with various amines at two different temperatures leading to the synthesis of arylglyoxal amides at 120 °C and aromatic amides at 180 °C. The two radicals, arylglyoxyl radical and aroyl radical, generated via decarbonylation at higher temperature, could react with amines via radical polar crossover.

A family of α-aminophosphonates, dimethyl (A), dipropyl (B), and diisopropyl (C), was synthesized through a green, catalyst-free Kabachnik-Fields reaction and characterized using FT-IR, NMR, and UV-Vis spectroscopy, single-crystal X-ray diffraction, DFT calculations, and multiscale physicochemical analyses. All compounds crystallize as asymmetric Janus-type dimers stabilized by strong intermolecular N-H⋯OP hydrogen bonds, with alkyl substituents tuning their packing efficiency, directional interactions, and supramolecular organization. SC-XRD and ωB97X-D calculations show excellent agreement with their bond lengths, angles, and overall geometry, validating their dimeric structural model. Vibrational and NMR data corroborate the donor-acceptor polarity of the amide N-H and phosphoryl groups, while XRPD and DLS measurements confirm their structural robustness and concentration-dependent aggregation. Photophysical analyses reveal consistent π → π* transitions on the aromatic amide core with substituent-dependent relaxation. Thermal analysis shows that A possesses the most ordered hydrogen-bonded lattice yet decomposes first due to internal strain, B melts earlier but decomposes slightly later owing to its reduced packing efficiency, and C exhibits the highest melting point via compact dispersive stabilization. DFT and QSAR results further indicate distinct electronic behaviors, where compound A exhibits stronger hydrogen-bonding propensity toward biological targets, B shows steric stabilization, and C balances polarity and hydrophobicity to achieve the most favorable drug-like profile. Overall, this study demonstrates that substituent-driven modulation of hydrogen bonding, steric effects, and dispersive forces enables precise control over the supramolecular and physicochemical properties of α-aminophosphonate dimers, positioning them as versatile scaffolds for pharmaceutical and materials applications.

Cyclized aromatic amides enable 2016.9 ms blue phosphorescence with 15.6% yield via a HLCT state, exhibiting a 68-fold lifetime enhancement over its non-cyclized couterpart.

Two series of alizarine derivatives containing vanillin scaffold (10a-h) or aromatic amide function (12a-h) were synthesized and structurally characterized. The cytotoxic evaluation revealed higher activity towards leukemia cancer cell lines (K562 and HL-60) than solid tumor cells (HeLa and MCF-7). The compound 10h, containing a benzyl group, showed the most prominent activity against K562 cells, and the lowest toxicity towards healthy cells among all active derivatives. The most active compounds 10f, 10h, and 12h were further investigated and induced a significant increase in the percentage of HeLa, K562, and HL-60 cells in the subG1 cell cycle phase in comparison with the control cells. Compounds 10f and 10h activated apoptosis in K562 cells through all three tested caspases, while derivative 12h only induced the activation of the main effector caspase-3. Molecular docking simulations suggest that these compounds can form stable complexes with caspase-3, consistent with their experimentally confirmed involvement in caspase-dependent apoptotic pathways. All three tested derivatives demonstrated moderate to strong binding to bovine serum albumin (BSA), with preferential occupation of subdomain IIA (site I), as supported both experimentally and through docking studies. The interaction study of these compounds with DNA indicated their ability to interact with ct-DNA through the minor groove.