Warfarin is an oral anticoagulant widely used in the treatment of cardiovascular diseases and remains a relevant model in pharmacological and structural studies. Its behavior in solution, particularly the equilibrium between different neutral species, is crucial for understanding its bioactivity and affinity for its molecular target, the VKOR enzyme. Nuclear magnetic resonance (NMR) studies and theoretical calculations based on density functional theory (DFT) have confirmed the existence in solution of keto and enol forms in dynamic equilibrium, in addition to cyclic hemiacetal species.

In this context, the DP4+ method, which statistically compares experimental and calculated chemical shifts, allows for the validation of structures with high precision, even in the presence of equilibrium species. Its Bayesian approach improves reliability in complex assignments, integrating ¹H and ¹³C data and solvent effects.

For the structural study, a commercial formula (sodium salt) was used. After its isolation by dissolution in water (filtering out insoluble residues under vacuum) and subsequent controlled acidification of the aqueous medium, the neutral compound was obtained and characterized by ¹HNMR in DMSO at different temperatures. One-dimensional and two-dimensional experiments (¹³CNMR, COSY, HSQC, HMBC, and NOESY) were also performed, and theoretical shifts were calculated with Gaussian 09 (B3LYP/6-31+G(d,p)).

The analysis revealed the presence of two neutral species in equilibrium (Keq = 1.8). The application of DP4+ allowed confirming that these species were two diastereomeric hemiacetals. The integration of NMR, DFT calculations, and DP4+ enabled a precise structural assignment of warfarin in solution, validating its complex chemical behavior.

In this work, we computationally investigated the effectiveness of heavy metal removal utilizing the siderophore, i.e. protochelin by calculating the siderophore's interaction & Gibb’s free energy with various heavy metal pollutants. In this work, DFT was used to calculate the interaction & Gibb’s free energy of Protochelin with several metals, including (Cr⁺⁶, Cr⁺³, Ni⁺², Cu⁺², Zn⁺², As⁺², Hg^+2, and Pb⁺²) using hybrid DFT functional PBE0 along with basis set def2-SVP and def2-TZSVP. Cr shows a high chelating affinity for Protochelin compared to other metals in order of (Protochelin-Cr⁺⁶ > Protochelin-As⁺³ > Protochelin-Cr⁺³ > Protochelin- Fe⁺³ > Protochelin-Ni⁺² > Protochelin-Cu⁺² > Protochelin-Pb⁺² > Protochelin-Zn⁺² > Protochelin-Hg⁺²). The research results indicate that a siderophore would be an excellent choice as a metal-chelating chemical. These results are further supported by various computational analyses such as FMOs analysis & DOS spectra (indicating there is a decrease in band gap in metal-protochelin complexes). Non-covalent Interaction (NCI) analysis was further employed to provide further insight into the nature and strength of intermolecular forces between protochelin and the targeted metal pollutants (Cr, Ni, Cu, Zn, As, Hg, Pb. Additionally, RMSD analysis showed minimal structural changes within a 2000 fs simulation at 25°C, 50°C, 75°C and 100°C proving that both protochelin and its metal complexes do not exhibit any physical changes at any of the mentioned temperatures thereby indicating the stability of protochelin-metal complexes. It is now viable to create plants and bacteria that may be utilized efficiently to sequester metal pollutants from the soil and water using various approaches, such as genetic engineering.

Abstract

Abstract

An important class of heterocyclic chemicals are Pyrimidine derivatives, providing a wide spectrum of biological activities in the form of antibacterial and antifungal, anti-HIV, anti-hypertensive, anti-inflammatory, anti-cancer, anti-convulsant, anti-depressant, and anti-tuberculosis acts. The chalcone group also has a significant impact on the pharmacological activity of compounds used for therapeutic purposes, acting as antibiotics, antioxidants, and anticancer agents. In this research, the derivative 1-(4-(4-(dimethylamino)-2-hydroxyphenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-5-yl) ethan-1-one was prepared. From the reaction of thiourea with acetyl acetone and 4-dimethylamino-2-hydroxybenzaldehyde, then the product was reacted with some aldehydes in the presence of ethanol and a little hydrochloric acid as a catalyst, after that the product was reacted with some aldehydes to prepare chalcone. The prepared derivatives were characterized by FT-IR, ¹H-NMR and ¹³C-NMR spectrum and melting point was measured as well as studying the biological activity of the prepared compounds as antibacterial. The molecular docking of these derivatives was also determined as anti-breast cancer by docking of prepared derivatives with (PDB:3eqm) protein by use (MOE 2015 program).The prepared compounds showed good efficacy as antibacterial agents against Gram-negative bacteria at diluted concentrations. Additionally, molecular docking studies demonstrated good efficacy of some derivatives as breast cancer inhibitors, along with a study of the toxic effects of the prepared compounds using the ProTox-3.0 program - Prediction of toxicity of chemicals.

Fullerene C₆₀ derivatives have been evaluated as potential photosensitizers (PSs) for the inactivation of microorganisms. Fullerenes exhibit several attractive features, including high photostability, absorption in the visible region of the spectrum, and the ability to generate reactive oxygen species (ROS). However, one of the main limitations for their application as PSs is their low solubility in polar solvents, which leads to aggregation in aqueous solutions and biological media, ultimately impairing efficient photoactivity. Nevertheless, advances in fullerene C₆₀ covalent chemistry have enabled the attachment of various functional groups to the spherical carbon cage, thereby enhancing their biological activity.

In this work, a PS derived from fullerene C₆₀ covalently linked to polyethyleneimine (PEI) was developed. PEI is a polymer that acquires positive charges at physiological pH and is capable of interacting with microbial cell membranes. The reaction was carried out in DMF in the presence of TEA at room temperature. The C₆₀-PEI conjugate was purified by dialysis in water for one week to eliminate the rest of the reagents that remained unreacted. UV-visible absorption in H₂O and N,N-dimethylformamide (DMF) indicated that the properties of the C₆₀ are preserved in the conjugate. Moreover, C₆₀-PEI generates singlet oxygen yielding a quantum yield value of 0.15 and 0.07 in DMF and H₂O, respectively. Thus, this methodology enabled the development of a fullerene-derived PS with promising properties for applications in polar environments.

Diketopyrrolopyrrole (DPP) compounds, initially developed as high-performance red pigments, have gained significant attention in recent years due to their remarkable optical, electronic, and structural properties. These characteristics make DPP derivatives highly attractive for a wide range of applications, including organic electronics, photovoltaics, sensors, and bioimaging. The core DPP structure offers a versatile scaffold that can be chemically modified to fine-tune solubility, stability, and intermolecular interactions, thereby expanding their functional potential.

In this work, we present a study on a series of thienyl-substituted DPP derivatives, where targeted modifications have been introduced by varying the alkyl chains attached to the nitrogen atoms of the DPP core. These structural variations influence the molecular packing, solubility, and optoelectronic behavior of the resulting compounds, which are critical parameters for device integration.

A key innovation in our approach is the application of microwave-assisted synthesis, which significantly enhances the efficiency and sustainability of the synthetic process. Unlike conventional heating methods, microwave irradiation enables significantly shorter reaction times (just 40 minutes compared to 12 hours), higher yields (up to 80% for long alkyl chains), and reduced energy consumption, aligning with green chemistry principles.

Our results highlight the effectiveness of combining molecular engineering with advanced synthetic techniques to produce DPP-based materials in a more environmentally friendly and time-efficient manner. This study provides valuable insights into structure–property relationships in DPP systems and offers a promising route for the development of next-generation organic semiconductors.

In this study, a novel bio-based heterogeneous catalyst composed of cellulose, EDTA, and sodium alginate was designed and synthesized through a straightforward protocol. In this regards, the catalyst benefits from an interconnected, synergistic network in which cellulose acts as a renewable matrix, EDTA serves as a chelating agent to improve active site accessibility, and sodium alginate contributes biodegradability and structural stability. The resulting composite shows excellent thermal endurance, catalytic recyclability, and green compatibility. Furtheremore, this catalyst was employed in a one-pot multicomponent condensation reaction for the synthesis of pyrano[2,3-c]pyrazole derivatives. The reaction involved aromatic aldehydes, a pyrazole-based amine compound, and either malononitrile or ethyl acetoacetate as the active methylene sources, conducted in ethanol under mild reflux conditions. The protocol demonstrated high efficiency, delivering the desired products in excellent yields with short reaction times and minimal environmental impact. Moreover, the recyclability of the catalyst was confirmed over multiple cycles with negligible loss of activity. Importantly, pyrano[2,3-c]pyrazoles are known for their wide range of pharmacological properties, including antimicrobial, anticancer, anti-inflammatory, and antioxidant effects. This study introduces a sustainable synthetic route that not only advances heterocyclic design but also aligns with green chemistry principles, offering potential for further applications in medicinal and pharmaceutical research.

Introduction. The synthesis of new symmetrical bridged bis(6-hydroxypyrimidin-4(3H)-ones) is of significant interest in modern chemistry and pharmaceuticals. Due to their unique structure, such systems have the potential to create new drugs with improved pharmacological properties. They are widely known for their antiviral, antitumor, and antibacterial properties, making them attractive candidates for the development of new therapeutic agents.
This work considers two approaches to the synthesis of new bis(6-hydroxypyrimidin-4(3H)-ones) with aromatic and aliphatic linkers.
Methods. Bis(6-hydroxypyrimidin-4(3H)-ones) (1 a-c), substituted with an aromatic 1,4-phenylene bridge at the 2,2' positions, were obtained by the reaction of N'¹,N'⁴-diphenylbenzene-1,4-dicarboximidamide with an excess of 2-substituted malonylchlorides. The 5,5'-substituted derivatives of bis(6-hydroxypyrimidin-4(3H)-one) with a trimethylene bridge (2 a-c) were obtained through the interaction of N-phenylimidamides and tetraethyl propane-1,1,3,3-tetracarboxylate. The structure of the synthesized compounds was confirmed using ¹H and ¹³C NMR spectroscopy.
Results and Conclusions. The yield of 2,2'-(1,4-phenylene)bis(6-hydroxy-5-substituted-3-phenylpyrimidin-4(3H)-ones) (1 a-c) ranged from 34-71%. It was found that the substituent in the malonylchloride affects the yield of the products. Alkyl substituents facilitate the obtainment of target compounds with higher yields compared to the aromatic phenyl group. The yield of 5,5'-propane-1,3-diylbis(6-hydroxy-2-substituted-1-phenylpyrimidin-4(3H)-ones) (2 a-c) ranged from 58-72%. It was discovered that the presence of aliphatic substituents in N-phenylimidamide leads to the obtainment of these compounds with higher yields compared to the use of N-phenylbenzocarboximidamide.

Bis-coumarins, a widely studied group of compounds associated with coumarins, have been shown to be active as anticoagulants, antiseptics, and urease inhibitors. For its part, multicomponent reactions are convergent processes that combine three or more reactants in a single operation to form a single product. They are invaluable in drug development due to their high atom economy and lack of generation of harmless byproducts.

In this work, nine bis-coumarin molecules were obtained by multicomponent reaction, without catalysts, under thermal heating or microwave irradiation. First, optimization tests were performed using one mol benzaldehyde and two mol of 4‑hydroxycoumarin as starting substrates. The optimal temperature (100 ºC), solvent (n-propanol), and reaction time (4 h for conventional heating and 1 h for microwave irradiation) were then employed for the reaction between 4‑hydroxycoumarin and different 3-formylchromones to obtain bis-coumarins. Excellent yields and selectivity, which in most cases was greater than 65%, both with conventional thermal heating and microwave radiation were achieved. It is noteworthy that the products are insoluble in the reaction solvent; therefore, they precipitate from the reaction medium and are obtained almost pure (corroborated by ¹H‑NMR, melting point determination) without the need for other separation or purification methods such as recrystallization, which require the use of additional solvents.

Lung cancer, encompassing tumors that originate in the bronchi or lung parenchyma, is one of the leading causes of cancer-related mortality worldwide. Historically, it was relatively uncommon at the beginning of the 20th century; however, the sharp increase in cases over subsequent decades has been primarily attributed to the rise in smoking among both men and women. Tobacco use remains the most significant cause of lung cancer, with cigarette smokers accounting for 80–90% of cases. In this context, Moringa Oleifera, commonly known as the drumstick tree, has attracted attention for its potential anticancer properties. Studies have demonstrated that extracts from M. oleifera exhibit strong anticancer activity against various tumors, including breast cancer, by modulating cell cycle regulatory genes and promoting apoptosis. This study aims to perform an in silico screening of 191 bioactive compounds from M. oleifera to identify potential natural inhibitors of Cyclin-Dependent Kinase 2 (CDK2), thereby exploring novel avenues for lung cancer treatment. The obtained results revealed that the plant contains compounds with high binding affinity toward CDK2, with the best-docked compound showing a binding free energy of –8.1 kJ/mol, which also passes Lipinski’s rule of five for drug-likeness. Furthermore, molecular dynamics simulation confirmed the stability of these interactions over time.

Introduction:
Fused nitrogen-containing heterocycles such as naphthyridines are privileged structural motifs found in a range of biologically active molecules and functional materials.^[1–3] Their unique electronic and structural features make them attractive scaffolds in drug discovery, fluorescence-based sensing, and optoelectronic applications.^[4,5] However, existing synthetic methods for these frameworks often involve multi-step procedures, harsh conditions, and limited control over stereoselectivity.^[6]

Methods:
In this work, we present a one-pot, silver-catalyzed method for the highly diastereoselective synthesis of fused polycyclic 1,7-naphthyridine derivatives. The reaction proceeds under mild conditions and tolerates a wide array of functional groups, allowing the incorporation of diverse substituents. The protocol is scalable to gram quantities and requires only celite filtration, evaporation, and column chromatography, eliminating the need for extensive purification.

Results:
This efficient and operationally straightforward method delivers products in good to excellent yields with high diastereoselectivity. The broad substrate scope and mild conditions showcase the robustness of the transformation. Structural confirmation and stereochemical outcomes were supported by NMR analysis and, in select cases, by single-crystal X-ray diffraction.

Conclusion:
This study expands the synthetic utility of silver catalysis in complex heterocycle construction. The resulting 1,7-naphthyridine derivatives are being further investigated for their photophysical properties with potential applications in light-emitting devices and solar energy materials. Simultaneously, their biological activity is being evaluated to identify leads of therapeutic relevance. Overall, this method provides a versatile platform for accessing functional heterocyclic frameworks relevant to materials science and medicinal chemistry.