It has been shown that 3-formylpyrazolo[1,5-a]pyrazine-4-carboxylates obtained by the selective formylation of pyrazolo[1,5-a]pyrazine-4-carboxylates react with 1,2-ethanediamine or 1,3-propanediamine in methanol at room temperature to give pentaazacyclopenta[d]acenaphthalenes or pentaazaaceanthrylenes.

The development of effective insecticides is crucial for sustainable agriculture. This research focuses on a series of pyridine derivatives (3–9) that were prepared and evaluated for their agricultural bioefficacy as potential insecticides against cowpea aphid, Aphis craccivora Koch (Homoptera: Aphididae). The results demonstrate significant variations in bioefficacy among the tested compounds. Toxicity index analysis revealed the following order of insecticidal activity: 8>4>6>3>5>7>9, highlighting compound 8 as the most potent. Furthermore, potential binding interactions were elucidated through molecular docking studies between these compounds and relevant insect target proteins. So, the observed bioactivity trends were rationalized with the use of the docking data, which offered useful information on the binding affinities and molecular interactions. AChE, or acetylcholine esterase (PDB ID: 2ACE), has been docked against the seven synthetic molecules (3–9). Interestingly, compounds (2-(pyridin-2-ylthio)acetonitrile; 8), (2-(pyridin-2-ylthio)acetic acid; 6), and (ethyl 2-(pyridin-2-ylthio)acetate; 4) had the highest binding affinity, with respective docking scores (S) of -7.51, -7.45, and -7.12 kcal/mol, while compounds (thieno[2,3-b]pyridine derivatives; 7 and 9) had the lowest binding affinity (S=-6.52 and -6.73 kcal/mol, respectively). According to protein-ligand docking configurations, these compounds exhibited a range of binding interactions inside the 2ACE active site. Hence, this study contributes to the development of new pyridine-based insecticides for sustainable pest management in agricultural applications.

The Diels-Alder cycloaddition of cyclopentadienone derivative 3-methyl-5,6,7,8-tetrahydroazulen-1(4H)-one with a series of maleimide derivatives is studied using Molecular Electron Density Theory at the B3LYP/6-311++G(d,p) computational level. Conceptual Density Functional Theory analysis predicts low reaction polarity, which is confirmed by global electron density transfer analysis at the transition structures. Topological analysis reveals the electron distribution and evolution of multiple covalent and non-covalent interactions at the transition structures. The results indicate that these Diels-Alder reactions follow an asynchronous one-step mechanism under kinetic control, favouring the endo product formation. Bonding Evolution Theory shows that the reaction mechanism can further be decomposed into five distinct bonding evolution phases. In addition, a molecular docking study is conducted to assess the antimicrobial potential of the reaction products against Escherichia coli and Staphylococcus aureus. An evaluation of the results of binding affinity and molecular interactions concludes that the products are viable as antimicrobial agents.

Metalaxyl-M is a modern and more efficient version of metalaxyl which is designated to provide effective control of damaging fungal diseases. This work aimed to develop and validate a low-cost, accurate, fast, and simple analytical method for determination of active ingredient metalaxyl-M using high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The development of the novel method was performed on reversed-phase brownlee™ C-18 column at constant temperature 30 ºC. The mobile phase consists of acetonitrile and distilled water in volumetric ratio 62.5:37.5, a flow rate of 1.2 mL/min, and the detective wavelength at 270 nm. The validation protocol underscore in our study was SANCO/3030/99 rev. 5. Specificity, linearity, LOD, LOQ, precision, recovery, and accuracy parameters were calculated and discussed. The values for multiple correlation coefficient (R² ≥ 0.990), relative standard deviation (RSD < 1.5 %), recoveries ranged from (99.21 - 101.16 %) were found within acceptance criteria.

Considering the very important medicinal and biological properties of heterocycles including isatin skeleton, synthesis of isatin-containing compounds has attracted the attention of medicinal and organic chemists, especially researchers involved in the synthesis of heterocycles. The present review focuses on the recent investigation in the synthesis of heterocycles with isatin moiety using isatin derivatives as reaction reactants via multi-component for the period of 2014–2024. The reports were classified according to the conditions of the reactions, which distinguishes this review from similar studies. In some reports, green chemistry has been used, such as the use of green solvent, green and reusable catalyst, solvent-free conditions, microwave irradiations and ultrasonic irradiations. Most reviews of isatin published so far have focused only on spirooxindoles, but this review not only addresses the condition for the synthesis of spirooxindoles, but also the synthesis of other isatin-contaning heterocycles such as pyrroloquinolines, imidazole-indoles and pyrazoloquinoline. The main objective of this review is to present an overview of the latest methodologies involving isatin in the multicomponent synthesis of heterocyclic compounds, specifically for organic and medicinal chemists.

This study examines the reactivity of an intramolecular cyclization process involving benzastatin, a molecule derived from Streptomyces nitrosporeus, using density functional theory (DFT) with the B3LYP functional and the 6-311G(d,p) basis set. Parr indices, calculated by natural bond orbital (NBO) analysis, provide insight into the reactivity and chemical behavior of the system. In addition, the electron localization function (ELF) is used to analyze bond formation during the process. A molecular docking study highlights the pharmacological potential of benzastatin-derived alkaloids against Plasmodium falciparum, the malaria parasite, by targeting the key enzymes falcipain-2 and falcipain-3. The study elucidates the key interactions and binding affinities between the reaction products involved and these enzymes, supported by molecular dynamics simulations to study the stability of the ligand-protein complex over 50 ns. ADMET predictions suggest favorable pharmacokinetic profiles and low toxicity for the compounds, underlining their potential as antimalarial drug candidates.

Angular pyrrolo(pyrido)[1,2-a]quinazolinones, being structurally isomeric to linear pyrrolo(pyrido)[2,1-b]quinazolinone alkaloids, are attractive molecular systems for both synthetic transformations and targeted biomedical research. The pyrrolo(pyrido)[1,2-a]quinazolinone scaffold has proven to be quite effective in the search for compounds with a wide range of pharmacological activities, e.g. anti-inflammatory, antioxidant, antibacterial, antiarrhythmic, and inhibitors of important biotargets. The present review summarises the methods for the synthesis of pyrrolo(pyrido)[1,2-a]quinazolinones as a comprehensive research object, especially in the past decade. They are systematised according to the type of heteroannulation and include the processes of cascade annulation of the pyrimidine and pyrrole (pyridine) cycles to anthranilamides (hydrazides); formation of a pyrimidine nucleus based on ortho-pyrrolyl(pyridinyl) substituted aromatic compounds; annulation of the pyrrole (pyridine) nucleus to a quinazolinone scaffold. It is expected that the generalised material presented will serve as a reliable guide for the rational design of new pharmacologically oriented compounds.

Population growth and economic development have led to an increase in global energy consumption. Solar energy, a major renewable source, is essential to meeting human energy needs. This study, four new organic dyes (A1–A4) with a D–π–D–A structure using DFT and TD-DFT techniques for their potential application in dye-sensitized solar cells (DSSCs). The impact of π-bridge modifications of the A0 (reference molecule) on the structural, photovoltaic, optical and electronic properties was analyzed. The dyes showed band gaps (Egap) ranging from 2.4 to 3.5eV and absorption wavelengths (λ) from 420.16 to 627.4nm. Results suggest that the modification of the π-bridge of dye A0 enhanced intramolecular charge transfer (ICT). and improved hole injection. Theoretical open-circuit voltages (Voc) varied between 1.15 and 2.36 eV, while light harvesting efficiency (LHE) values ranged from 0.80 to 0.93. This study could effectively assist chemists in the synthesis of efficient dyes for DSSCs.

The (3+2) cycloaddition reactions of 2-diazopropane with derivatives of 5-hydroxy-3-methyl-1,5-dihydropyrrol-2-one were investigated using Molecular Electron Density Theory. Calculations were performed at the wB97XD/6-311++G(d,p) level of theory. Conceptual Density Functional Theory indices revealed a low polar character for these reactions, supported by a minimal global electron density transfer at the transition structures, which were classified as forward electron density flux processes. The Electron Localization Function analysis identified 2-diazopropane as a pseudo(mono)radical three-atom component. It further indicated that bond formation does not start at the transition structures. Mechanistically, these reactions proceed via an asynchronous one-step mechanism, ultimately leading to products that are kinetically favored. Furthermore, molecular docking studies were conducted to evaluate the antifungal potential of the reaction products against pathogenic fungal strains, Candida albicans and Aspergillus fumigatus. The docking analysis assessed binding affinities and characterized molecular interactions between the proposed compounds and critical fungal proteins, highlighting their potential as antifungal agents.

A combined experimental and theoretical study of the fundamental thermodynamic parameters of 3-(5-phenyl-1-(pyridin-3-yl)-1H-pyrrol-2-yl)propanoic acid was carried out for the first time. The enthalpies of combustion, formation in the condensed state, fusion, and vaporization were determined using high-precision equipment. Based on the experimentally obtained results, the enthalpies of sublimation and formation in the gaseous state at 298.15 K were calculated using two methods. The possibility of applying analytical methods of Domalski, Joback and quantum chemical calculations to determine the enthalpy of formation in the gas phase is analysed.