Sampath Chinnam

As the most varied class of organic compounds, N-heterocycles—especially pyrimidine derivatives, which are found in many remarkable synthetic substances—have important chemical, biological, and industrial uses. This review sheds light on a number of techniques for building diverse fused pyrimidine scaffolds using N-heterocycle moieties as adaptable precursors. Recent studies demonstrate the promise of pyrimidine-based heterocyclic hybrids, particularly those with bicyclic (pyrido[2,3-d]pyrimidine and pyrano[2,3-d]pyrimidine) and tricyclic (pyrido[2,3-d:5,6-d′]dipyrimidine) moieties that exhibit enhanced cytotoxicity and target selectivity. Because they developed N-heterocyclic-based pyrimidine analogous frameworks in a single reaction step, multicomponent reactions are crucial in the advanced, proficient synthesis of medications. Green along with ecofriendly protocols for syntheses of such organic moieties are essential for sustainable growth of the pharmaceutical and agrochemical fields. This review highlights the structure–activity relationships guiding the advancement for next-generation pyrimidine pharmaceutical chemotypes and embraces various synthetic strategies and summarizes recent research developments, as well as reveals the many important biological characteristics (anticancer, in vitro α-amylase inhibitory, antimicrobial, antiviral, anti-inflammatory, antioxidant, antituberculosis, antidiabetic, anticholinesterase, antiplatelet, and in vitro antimalarial agents).

Chalcone-based analogues have gained significant attention due to their promising inhibitory activity against multiple viral targets. To identify potential anti-SARS-CoV-2 drug candidates, we designed and synthesized novel chalcone analogues via the Claisen–Schmidt reaction, affording excellent product yields (87–94%). Compound 3c was crystallized by slow evaporation of an ethanolic solution at room temperature. X-ray diffraction analysis revealed that the compound crystallized in the monoclinic crystal system with P21/c space group. The crystallographic data uncovered crystal packing, bond lengths, bond angles and other key parameters. Docking studies revealed that the synthesized compounds 3(a–d) exhibited moderate binding affinities, with compound 3d showing the strongest affinity at −4.657 kcal mol−1. These values are less favourable than the reference inhibitors (−7.424 and −8.245 kcal mol−1 for the co-crystallized ligand and remdesivir, respectively), suggesting potential for further optimizations through medicinal chemistry approaches. The molecular dynamics simulations of the 3d complex demonstrated fluctuations within a satisfactory range (2.5–4.5 Å), as observed in the root mean square deviation plots at 100 ns. Furthermore, absorption, distribution, metabolism and excretion analysis indicated that all compounds displayed drug-like properties, with high gastrointestinal absorption, suggesting bioavailability. The present work provides a promising platform for further development of chalcone-based compounds as promising anti-SARS-CoV-2 agents.

α-MnMoO ₄ nanocubes serve as a bifunctional material, acting as a light-driven photocatalyst for the degradation of organic pollutants and as a heterogeneous catalyst for conversion of o -phenylenediamine into 2-substituted benzimidazole derivatives.

The increasing energy demand and environmental challenges associated with fossil fuel use have spurred interest in renewable energy sources, particularly biofuels derived from waste biomass and plastics. This study investigates the catalytic co-pyrolysis of pistachio nutshells (PNS) and polystyrene (PS) to produce pyrolysis oil and char with enhanced fuel properties. The experiments were conducted in a semi-batch reactor under varying temperatures (500–650 °C), 30 °C min⁻¹ heating rate, and 100 mL min⁻¹ inert gas flow rate. Furthermore, PS loadings (20–50 wt%) and CuO loadings (5 and 10 wt%) were employed to improve the pyrolysis oil characteristics. The optimum conditions were found to be 550 °C with 30 wt% PS and 5 wt% CuO loading, yielding a maximum bio-oil output of 49 wt%. The characterisation of the pyrolysis oil revealed significant improvements in fuel quality with catalytic treatment, including an increased higher heating value (HHV) of 35.90 MJ kg⁻¹, reduced oxygen content (11.69 wt%), and lower viscosity (36.40 cP). Similarly, the resulting biochar exhibited high carbon content (76.57 wt%), low ash and moisture content (<1%), and enhanced calorific value, indicating its potential as a solid fuel or soil amendment. FTIR and NMR analyses confirmed the reduction of oxygenated functional groups and the presence of desirable hydrocarbon structures in the oil, while XRD and SEM analyses demonstrated improved structural properties of the char. The results highlight the synergistic benefits of co-processing biomass and plastic waste, as well as the catalytic role of CuO in enhancing product quality. This approach offers a sustainable waste-to-energy pathway, promoting circular economy principles and advancing the production of renewable fuels from mixed solid wastes.

In this study, we have synthesized novel thiohydrazone 3(a–b) and hydrazone analogues 3(c) by one-pot methodology with good to excellent yields (85%–91%). In silico molecular dynamics (MD) simulations, docking, and absorption, distribution, metabolism, excretion and toxicity (ADMET) were evaluated as inhibitor activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PDB ID: 5N5O) main protease. The dynamics simulations studies and docking were conducted by GROMACS and AutoDock Vina. The ADMET studies of all the compounds were evaluated to understand drug-likeness and potential for therapeutic applications. All the synthesized compounds 3(a–c) exhibited strong docking scores between −5.0 and −5.4 kcal mol ⁻¹ to the targeted protein. MD simulations revealed that the 3b protein–ligand complex demonstrated conformational stability throughout most of the 70 ns simulation period with root mean square deviation (RMSD) fluctuations below 3 Å. ADMET predictions indicated that all compounds possessed high gastrointestinal absorption, suggesting good oral bioavailability. By slow evaporation technique, crystals of compound 3b were grown using ethanol and its single crystal X-ray diffraction analysis disclosed that it crystallized in the monoclinic (P2 ₁ /c) crystal system. Crystal data outlined crystal packing, bond lengths, bond angles, intermolecular hydrogen bonding parameters, etc. This study offers further avenues in the discovery of novel and promising hydrazone analogues against SARS-CoV-2 main protease.