Chemical Applications Research Articles

Computational design for enantioselective CO2 capture: asymmetric frustrated Lewis pairs in epoxide transformations.

Carbon capture and utilisation (CCU) technologies offer a compelling strategy to mitigate rising atmospheric carbon dioxide levels. Despite extensive research on the CO2 insertion into epoxides to form cyclic carbonates, the stereochemical implications of this reaction have been largely overlooked, despite the prevalence of racemic epoxide solutions. This study introduces an in silico approach to design asymmetric frustrated Lewis pairs (FLPs) aimed at controlling reaction stereochemistry. Four FLP scaffolds, incorporating diverse Lewis acids (LA), Lewis bases (LB), and substituents, were assessed via volcano plot analysis to identify the most promising catalysts. By strategically modifying LB substituents to induce asymmetry, a stereoselective catalytic scaffold was developed, favouring one enantiomer from both epoxide enantiomers. This work advances the in silico design of FLPs, highlighting their potential as asymmetric CCU catalysts with implications for optimising catalyst efficiency and selectivity in sustainable chemistry applications.

Effects of GroMore® Program on Rice Yield and GHG Emissions in a Korean Paddy Rice

The agronomic benefits of pesticides combined with amino acid application to increase rice production have been recognized, but they are still not well-known for greenhouse gas (GHG) emissions and mitigation in irrigated paddy fields. Thus, this study was conducted to investigate the combined effects of pesticide and amino acid application on rice yield and methane (CH4) emissions in a Korean rice paddy. A field experiment was conducted with five levels: none (no pesticide application, T1), different conventional practices (combined application of insecticides and fungicide, T2 and T3), and GroMore® programs (combined application of insecticides, fungicides, and amino acids, T4 and T5). Rice grain yield and yield components were obtained using agronomic measurements. To determine the greenhouse gas intensity (GHGI) of each treatment, CH4 emissions were measured throughout the rice growing period. Results showed that the chemical applications in combination with amino acids in T4 obtained a higher grain yield and number of panicles per plant compared to T1, T2, and T3, while T4 and T5 showed no difference on filled spikelets except for T2. T3 and T5 showed lower respective cumulative CH4 emissions by 30% and 32% during the entire rice growing season, compared to no chemical application (T1). Meanwhile, N2O emissions were negligible in all treatments because the paddy field was flooded most of the growing season. The results of the impact of GroMore® programs on relatively higher grain yield and lower GHG emissions are presented. In conclusion, the application of pesticides combined with amino acids obtained lower GHGI values.

Isolation and Characterization of Stigmasterol from Psidium guajava Leaves: A Promising Bioactive Compound with Therapeutic Potential

This study aimed to isolate and characterize bioactive compounds from the leaves of Psidium guajava Linn. The hydroethanolic extract yielded 32% (80 g) from the crude material, which was subjected to column chromatography for fractionation. Structural elucidation of the isolated compound was performed using 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy, including COSY, HSQC, and HMBC experiments. The spectral data confirmed the presence of stigmasterol, characterized by its distinct chemical shifts and long-range correlations between carbon and proton atoms. Stigmasterol was isolated as a white, crystalline solid and identified by its unique physio-chemical properties, such as solubility in organic solvents, a melting point of 163-164°C, and molecular formula C29H48O. This compound is known for its significant biological activities, including antibacterial, antimalarial, anti-inflammatory, antioxidant, and anticancer effects. By employing advanced techniques like 1D and 2D NMR spectroscopy, the study provides precise structural elucidation of stigmasterol, contributing to natural product research and reinforcing the medicinal potential of guava leaves as a source of pharmacologically active compounds. This adds to the existing knowledge of the plant’s bioactive components and their applications in medicinal chemistry

Electrochemical Ferrier Rearrangement of Glycals.

The Ferrier rearrangement (FR) is a well-documented reaction that relies on strong acids or oxidants to convert glycals into unsaturated glycosyl derivatives. In this work, we introduce an electrochemical variant of the FR, offering a broad substrate compatibility. Various nucleophiles and glycal derivatives afford 2,3-unsaturated glycosyl derivatives in high yields with excellent diastereoselectivities. This sustainable method promises to expand the electrochemistry applications in sugar chemistry.

Conversion of Lignin to Nitrogenous Chemicals and Functional Materials.

Lignin has long been regarded as waste, readily separated and discarded from the pulp and paper industry. However, as the most abundant aromatic renewable biopolymer in nature, lignin can replace petroleum resources to prepare chemicals containing benzene rings. Therefore, the high-value transformation of lignin has attracted the interest of both academia and industry. Nitrogen-containing compounds and functionalized materials are a class of compounds that have wide applications in chemistry, materials science, energy storage, and other fields. Converting lignin into nitrogenous chemicals and materials is a high-value utilization pathway. Currently, there is a large amount of literature exploring the conversion of lignin. However, a comprehensive review of the transformation of lignin to nitrogenous compounds is lacking. The research progress of lignin conversion to nitrogenous chemicals and functional materials is reviewed in this article. This article provides an overview of the chemical structure and types of industrial lignin, methods of lignin modification, as well as nitrogen-containing chemicals and functional materials prepared from various types of lignin, including their applications in wastewater treatment, slow-release fertilizer, adhesive, coating, and biomedical fields. In addition, the challenges and limitations of nitrogenous lignin-based materials encountered during the development of applications are also discussed. It is believed that this review will act as a key reference and inspiration for researchers in the biomass and material field.

Wear and corrosion resistance of textured and functionally particle-enhanced multilayer dual-biomimetic polymer coatings

This study presents a dual-biomimetic polymer coating with improved wear and corrosion resistance, inspired by natural biological structures of shells and superhydrophobic surfaces. The coating is composed of alternating hard epoxy resin layers, modified with benzotriazole-functionalized silica for corrosion protection, and soft fluorocarbon resin layers, enhanced with graphene oxide for improved mechanical properties. Surface textures were added using a soft template method to boost hydrophobicity and reduce wear. The coating demonstrated excellent hardness, impact resistance, and corrosion protection, particularly in simulated seawater. Additionally, surface textures further minimized wear by trapping debris. This design strategy offers a promising approach for advanced polymer coatings in marine, machinery, and chemical applications, combining durability, protection, and self-healing properties.

The impact of combined application of biochar and fertilizer on the biochemical properties of soil in soybean fields.

Heilongjiang Province is a major soybean production area in China. To improve soil structure and increase soybean yield, this study examined the effects of combined biochar and chemical fertilizer application on the biochemical properties of soil in a maize-soybean rotation system. The research were conducted from 2021 to 2022 at Heshan Farm Science Park in Heilongjiang Province, this field plot experiment utilized two soybean varieties, Heihe 43 (a high-protein variety) and Keshan 1 (a high-oil variety). In 2021, two plots with similar fertility levels were selected for planting soybeans and maize. In 2022, a maize-soybean rotation was implemented with five treatments: conventional fertilization (CK), increased biochar+reduced fertilizer 1 (F1+B), reduced fertilizer 1 (F1), increased biochar+reduced fertilizer 2 (F2+B), and reduced fertilizer 2 (F2). The study systematically analyzed the effects of combined biochar and chemical fertilizer application on soil chemical properties and microbial characteristics. Over 2 years, results showed that combined application effectively improved soil chemical traits. Compared to conventional fertilization (CK) and reduced fertilization (F1, F2), t he combined application of biochar and chemical fertilizer (F1+B, F2+B) increased soil pH, EC and the absolute value of zeta potential of soil surface, the CEC of soil significantly increased by 15.6-44.3%, the soil surface charge density and the soil surface charge quantity significantly increased by 16.4-73.5%. The combined application of biochar and chemical fertilizer also effectively enhanced the abundance and diversity of soil microbes. Dominant bacterial groups in soybean field soils under different treatments included Actinobacteria, Acidobacteria, Chloroflexi, and Proteobacteria; while dominant fungal groups were Ascomycota, Basidiomycota, and Mortierellomycota. Alpha and Beta diversity analyses revealed that the F1+B treatment significantly enhanced the species richness and diversity of bacteria and fungi in the soil, increasing the proportion and evenness of dominant and beneficial genera.

FSscore: A Personalized Machine Learning‐Based Synthetic Feasibility Score

AbstractDetermining whether a molecule can be synthesized is crucial in chemistry and drug discovery, as it guides experimental prioritization and molecule ranking in de novo design tasks. Existing scoring approaches to assess synthetic feasibility struggle to extrapolate to new chemical spaces or fail to discriminate based on subtle differences such as chirality. This work addresses these limitations by introducing the Focused Synthesizability score (FSscore), which uses machine learning to rank structures based on their relative ease of synthesis. First, a baseline trained on an extensive set of reactant‐product pairs is established, which is then refined with expert human feedback tailored to specific chemical spaces. This targeted fine‐tuning improves performance on these chemical scopes, enabling more accurate differentiation between molecules that are hard and easy to synthesize. The FSscore showcases how a human‐in‐the‐loop framework can be utilized to optimize the assessment of synthetic feasibility for various chemical applications.

Self-Assembled BODIPY@Au Core-Shell Structures for Durable Neuroprotective Phototherapy.

BODIPY analogs are promising photosensitizers for molecular phototherapy; however, they exhibit high dark cytotoxicity and limited singlet oxygen generation capacity. In this study, we developed self-assembled core-shell nanophotosensitizers by linking a bipyridine group to BODIPY (Bpy-BODIPY) and promoting J-aggregation on gold nanourchins. This design enhances photostability and reduces the energy gap between the lowest singlet excited state and the lower triplet state, facilitating efficient singlet oxygen production. We characterized these nanophotosensitizers using UV-visible spectroscopy, transmission electron microscopy (TEM), surface-enhanced Raman spectroscopy (SERS) and dynamic light scattering (DLS), which confirmed the formation of the desired core-shell structure and J-aggregates. Notably, Bpy-BODIPY@Au significantly suppresses tau protein aggregation and enhances neuroprotective action, even in the presence of a phosphatase inhibitor. This work broadens the application of BODIPY chemistry to nanoagents for neuroprotective therapy.

GQDs@SiO3Pr Schiff-base complexes Co (II); As an eco-friendly environmental nanocatalyst for the synthesis of the amino carbonitrile chromenes

An effective nanocomposite comprising functionalized graphene quantum dots has been developed for the rapid, one-step production of amino carbonitrile chromenes. To this end, the surface of graphene quantum dots (GQDs) was functionalized with a novel synthetic Schiff-base complex of cobalt (II) prepared by post-synthetic surface modification of the graphene quantum dot surface with a silane coupling agent (3-chloropropyl trimethoxysilane, SiO3PrCl) in order to synthesize GQDs@SiO3PrCl. Then, the Schiff base ligand synthesized from the condensation reaction of 4-aminoantipyrine with ortho-phenylenediamine was immobilized on the surface of the silane-linker grafted GQDs to synthesize the GQDs@SiO3Pr-Schiff base. Finally, the cobalt particles were stabilized on the surface of the graphene quanta functionalized with Schiff bases (GQDs@SiO3Pr-Schiff Base/Co (II)). The GQDs@SiO3Pr-Schiff Base/Co (II) nanocatalyst demonstrated exceptional performance in the synthesis of amino carbonitrile chromenes derivatives, facilitating high product yields using various aromatic aldehydes, 4‑hydroxy coumarin and malononitrile under mild conditions. Additionally, the catalyst exhibited reusability up to seven times without significant loss of productivity, showcasing its environmental friendliness and sustainability in organic synthesis. This versatile nanocatalyst holds promising for efficient and economically viable catalysis in diverse chemical applications.

A Planar Darkfield Illuminator for Wide‐Field High‐Contrast Imaging of Specimens in Microfluidic Chips

AbstractDarkfield microscopy is an effective technique and well suited for use involving live and unstained biological samples, where a bulky condenser should be precisely aligned in the optical path to produce a cone of illumination light. Here, a compact darkfield illuminator is invented that has a planar shape and can work at broadband wavelengths. It can be easily incorporated into a conventional microscope as a substrate to produce hollow cones of light for large‐area darkfield illumination, resulting in a high‐contrast high‐sensitivity widefield microscopy images. Taking advantages of its planar and compact structure, this darkfield illuminator is successfully integrated with a microfluidic chip; thus, the actions and reactions of biological and chemical specimens flowing inside micrometer‐sized channels, can be real‐time imaged with high contrast and sensitivity in a large field‐of‐view (FoV). For the first time, the work integrates a compact darkfield illuminator with microfluidic chips, which produces a new platform for applications in biology, chemistry, and biomedical engineering.

Gold‐Catalyzed Heck and Suzuki‐Type Reactions: Challenges and Recent Advances

AbstractTransition metal‐catalyzed Suzuki and Heck reactions are two of the most common carbon‐carbon bond formation reactions. Gold, unlike other transition metals (Pd, Ni, and Cu), offers unique reactivity profiles, and has emerged as an efficient tool in the field of synthetic organic chemistry. This mini‐review focused on the recent work in gold‐catalyzed Heck and Suzuki‐type reactions, especially by photocatalysts or ligand design, which show reactivities and features distinct from other transition metals. These discoveries will further facilitate the development of gold redox catalysis as well as applications in organic synthesis, biochemistry, and medicinal chemistry.

Advances in the Synthesis of 3‐Acyl‐2‐Pyridones: Strategies and Methods for Accessing the Versatile Scaffold

ABSTRACTThe syntheses and bioevaluation of 3‐acyl‐2‐pyridones have garnered significant interest in recent years as a novel class of compounds with diverse biological activities. The bioactivities cover a wide range of therapeutic areas including antimicrobial, antitumor, anti‐inflammatory, antifungal, antibiotic, neuritogenic, cytotoxic, and antiviral activities. Therefore, 3‐acyl‐2‐pyridone scaffold offers a versatile platform for the development of new molecules with potential applications in medicinal chemistry. The recent exploration on synthesis and bioevaluation of 3‐acyl‐2‐pyridones has yielded promising results, making them attractive targets for further optimization and development of new therapeutic agents. This review summarizes the available information on total synthesis of 3‐acyl‐2‐pyridone containing natural products, and the other synthetic strategies developed for accessing the 3‐acyl pyridones such as multicomponent synthesis, condensation reaction, microwave‐assisted synthesis, catalytic hydrogenation reactions, metalation reaction, Michael addition, and formylation reactions. The presented information may serve as a valuable resource for researchers working in the field of medicinal chemistry and drug discovery, stimulating further exploration and development of this intriguing scaffold.

Catalytic Promiscuity of Fatty Acid Photodecarboxylase Enables Stereoselective Synthesis of Chiral α‐Tetralones

AbstractIn the field of biocatalysis, discovering novel reactivity from known enzymes has been a longstanding challenge. Fatty acid photo‐decarboxylase from Chlorella variabilis (CvFAP) has drawn considerable attention as a promising photoenzyme with potential green chemistry applications; however, its non‐natural reactivity has rarely been exploited to date. Herein we report a non‐natural reductive dehalogenation (deacetoxylation) reactivity of CvFAP inspired by its natural oxidative decarboxylation process, enabling the stereoselective synthesis of a series of chiral α‐substituted tetralones with high yields (up to 99 %) and e.r. values (up to 99 : 1). Mechanistic studies demonstrated that the native photoenzyme catalyzed the reductive dehalogenation via a novel mechanism involving oxidized state (FADox)/semiquinone state (FADsq) redox pair and an electron transfer (ET)/proton transfer (PT) process of radical termination, distinct from the previous reports. To our knowledge, this study represents a new example of CvFAP promiscuity, and thus expands the reactivity repertoire of CvFAP and highlights the versatility of CvFAP in asymmetric synthesis.

Multiplexed SERS Detection of Serum Cardiac Markers Using Plasmonic Metasurfaces.

Surface-enhanced Raman spectroscopy (SERS) possesses exquisite molecular-specific properties with single-molecule sensitivity. Yet, translation of SERS into a quantitative analysis technique remains elusive owing to considerable fluctuation of the SERS intensity, which can be ascribed to the SERS uncertainty principle, a tradeoff between "reproducibility" and "enhancement". To provide a potential solution, herein, an integrated multiplexed SERS biosensing strategy is proposed, which features two distinct advantages. First, a subwavelength-structured plasmonic metasurface consisting of alternately stacked metal-dielectric pyramidal meta-atoms is fabricated and could provide simultaneously enhanced electric and magnetic fields to enable spatially extended and weakly wavelength-dependent SERS. Second, nanomechanical perturbations are harnessed to transduce signals in the form of SERS frequency shifts, which are not directly affected by the SERS uncertainty principle. By also employing 3D printing methods, a proof-of-concept study of multiplexed detection of a panel of serum cardiac biomarkers for acute myocardial infarction is provided. Success in the development of both the electric and magnetic fields-active plasmonic metasurfaces could transform future designs of SERS substrates with newly endowed functionalities, and frequency shift-based SERS multiplexing could open new opportunities to develop innovative quantitative optical techniques for applications in chemistry, biology, and medicine.

Electronegativity Effects on Conformational Stability Using Bent's Rule: From Simple Molecules to Acetylcholine

Hybridization and electronegativity are fundamental concepts in chemistry connected by Bent's rule. This rule explains many aspects of the structural chemistry and reactivity of organic and inorganic compounds. Over decades, the application of Bent's rule has expanded, demonstrating its wide-ranging utility in elucidating molecular stability due to the substitution of highly electronegative atoms. This study successfully leverages Bent's rule to explain conformational energy difference in acetylcholine case using density-functional calculations. We used butane (Group 2) and butanone (Group 3) families to model the head of ACh+ and substituted one of the carbons with highly electronegative atoms: B, C, N, and O. This enabled us to evaluate the effects of electronegativity, as well as the presence of carbonyl groups, on their conformational stability and s character. There were three highlighted results. First, our calculations result in the s character are consistent with Bent's rule. Second, the high conformational energy differences can be attributed to the changes of s character in C2–Z bond: linear in Group 2 and exponential in Group 3, indicating the strong contribution of the carbonyl group. Third, the key determining factor in ACh+ conformational stability is the carbonyl group, which also strongly contributes to the solute-solvent interactions. Therefore, our study can be further applied to other similar molecules, potentially leading to broader applications in chemistry, especially for understanding ACh+ stability for Alzheimer’s Disease treatment.

Use of Differential Equations in Population Growth Analysis

In this assignment we discussed differential equation applications in real-world scenarios. Differential equations are a significant area of mathematics with applications in many fields, including engineering, astronomy, biology, chemistry, physics, economics, and finance. Differential equations are used in economics to explain many concepts such as restricted and infinite growth, equilibrium and stability, and the dynamics of supply and demand in an economy. Differential equations will be used to examine several facets of Nepal in this research assignment.

Effective Identification and Highly Sensitive Quantification of Fructo-oligosaccharide Isomers with Bi2Se3 Nanosheet-Assisted Laser Desorption Ionization Mass Spectrometry.

The growing interest in fructo-oligosaccharides (FOSs) necessitates the effective monitoring of product quality. Identifying and quantifying FOS isomers from the same sources are challenging. Here, we report a new method using Bi2Se3 nanosheets as the matrix for matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), achieving effective differentiation of oligosaccharide isomers through MALDI-MS/MS. Notably, four isomers of pentasaccharides and two isomers of heptasaccharides were successfully identified, with a remarkably low limit of detection of 0.06 pmol. Our approach enabled the specific quantification of 1F-fructofuranosylnystose in commercial FOS products, positioning it as a promising tool for oligosaccharide isomer quantification in nutritional food products. Furthermore, this technique facilitates the rapid and sensitive detection of various saccharides and a wide range of other small molecules with enhanced signal intensities and improved reproducibility. Overall, it facilitates the rapid, selective, and sensitive detection of various saccharides and other small molecules, enhancing analytical chemistry and food science applications.

Si-Linked Glycomimetics through a Stereoselective Silicon Transfer and Anion Addition.

We report a synthesis of silicon-linked glycomimetics, demonstrating unique structural properties and metabolic stability due to the inertness of the C-Si bond. Our method focuses on the stereoselective transfer of silicon and anion addition, revealing that chirality at the silicon atom can be controlled through kinetic resolution. This approach allows for the selective generation of 1,2-cis and 1,2-trans isomers via the manipulation of C2-protected silicon ethers and nucleophilic opening of glycal epoxides. We achieved high selectivity at the anomeric carbon and expanded the scope to include various saccharides and substituted silanes. Our findings indicate that silicon transfer occurs intramolecularly and is influenced by the nature of the counterion and reaction conditions. Additionally, chiral silanes produced through our method hold promise for medicinal chemistry applications, addressing significant gaps in the synthesis and utility of glycomimetics. This work opens new avenues for the development of bioactive silicon-based molecules.

Plant-mediated synthesis of biocompatible ZnO NPs: comprehensive characterisation and investigation of their catalytic, corrosion inhibition, antibacterial, scavenging and anti-oncogenic activities

ABSTRACT In this study, we present a novel method for synthesising zinc oxide nanoparticles (ZnO NPs) from the dried Caesalpinia sappan seeds powder. Comprehensive characterisation using XRD, FTIR, SEM, and EDX techniques was employed to elucidate the surface and morphological properties of these ZnO NPs. We showcase the versatile application of ZnO NPs as heterogeneous catalyst in the synthesis of 5-arylmethylidene-pyrimidin-2,4,6-triones. Notably, this eco-friendly approach eliminates the need for organic solvents, offering a sustainable route to producing 5-arylmethylidene-pyrimidin-2,4,6-triones in high yields. Furthermore, we investigate the corrosion inhibition properties of ZnO NPs on mild steel in 5% sodium chloride solution. Our findings reveal the ZnO NPs’ significant inhibition efficiency against corrosion, promising potential for practical applications. In addition to their chemical applications, we delve into the biological activities of ZnO NPs, including their antibacterial effects against both Gram-positive and Gram-negative bacteria, anti-oncogenic activity against DU-145 cells, and scavenging activities against oxidative stress.