Carbonyl Research Articles

Girard Derivatization-Based Enrichment Strategy for Profiling the Carbonyl Submetabolome in Biological Samples.

Numerous bioactive compounds containing carbonyl groups, including aldehydes and ketones, are widely acknowledged as potential biomarkers for several diseases and are implicated in the development of metabolic disorders. However, the detection of carbonyl metabolites is hindered by challenges, such as poor ionization efficiency, low biological concentration, instability, and complexity of the sample matrix. To overcome these limitations, we developed a Girard derivatization-based enrichment (GDBE) strategy for capturing and comprehensively profiling carbonyl metabolites in biological samples. A functionalized resin, named carbonyl capture and reporter-ion installation (CCRI) resins, was synthesized to selectively capture carbonyl metabolites via a Girard reaction. After unwanted metabolites were removed, the hydrazone derivatives were cleaved from the solid-phase resins and subjected to LC-MS analysis. The proposed GDBE strategy exhibits exceptional selectivity for capturing and enriching carbonyl metabolites. Moreover, this method surpasses current detection limits by enhancing the MS sensitivity and facilitating structural characterization of hydrazone derivatives by a specific MS/MS fragmentation signature. Using the GDBE method, 957 potential carbonyl metabolites were successfully identified in liver tissue from alcohol-fed mice. Among them, 76 carbonyl metabolites were annotated, indicating the potential of this strategy for the efficient nontargeted profiling of the carbonyl submetabolome in complex biological samples.

Chlorogenic Acid: A Promising Strategy for Milk Preservation by Inhibiting Staphylococcus aureus Growth and Biofilm Formation

Chlorogenic acid (CGA), a polyhydroxy phenolic acid, has been extensively studied for its antimicrobial properties. Staphylococcus aureus (S. aureus) threatens food safety by forming biofilms. This study aimed to investigate the mechanism of CGA against S. aureus and its biofilm. The anti-bacterial activity of CGA was assessed using crystal violet staining, TEM, SEM, a CLSM, and using metabolomics and molecular docking to elucidate the mechanism. The results indicated that the minimum inhibitory concentration of CGA against S. aureus was 2.5 mg/mL. CGA disrupts the integrity of bacterial cell membranes, leading to increased hydrophobicity, morphological changes, scattering, and reduced spreading. This disruption decreases biofilm adhesion and bacterial count. Metabolomics and molecular docking analyses revealed that CGA down-regulates key amino acids. It forms hydrogen bonds with penicillin-binding protein 4 (PBP4), Amidase, glutamate synthetase B, and glutamate synthetase A. By inhibiting amino acid metabolism, CGA prevents biofilm formation. CGA interacts with amino acids such as aspartic acid, glutamine, and glutamate through hydroxyl (-OH) and carbonyl (-C=O) groups. This interaction reduces cell viability and biofilm cohesion. The novel findings of this study, particularly the extension of the shelf life of pasteurized milk by inhibiting S. aureus growth, highlight the potential of CGA as a promising anti-biofilm strategy and preservative in the dairy industry.

Tracking the Changes of DOM Composition, Transformation, and Cycling Mechanism Triggered by the Priming Effect: Insights from Incubation Experiments.

The priming effect (PE) is recognized as an important mechanism influencing organic matter transformation in aquatic systems. The land-ocean aquatic continuum (LOAC) has received large quantities of dissolved organic matter (DOM) from various sources, which is an ideal interface for PE research. Here, we investigated the PE process by utilizing such a coastal environment to explore the turnover of DOM in the LOAC system. Suwannee River natural organic matter was selected as the background, and various external environmental samples were introduced to track the changes of organic carbon. The PE process together with the variations of DOM sources, compositions, and structures was characterized. Generally, river and estuary environments exhibited a positive PE, while the offshore zone showed a negative effect. Additionally, nutrients, salinity, and DOM composition all contributed to the PE. After the incubation, the feature of carbon sources transferred from terrestrial to autochthonous. The carbonyl and alcohol functional groups significantly decomposed, while the methyl and methylene groups increased and heteroatoms further accelerated the PE process. The data also shows that special parameters and molecular markers can be utilized to track the carbon response to the PE. This research indicates that the change of carbon flux and the imbalance of its budget in aquatic systems could be partially explained from the perspective of the PE.

Mechanical and chemical characterization of biochar-reinforced polystyrene composites

This study investigates the chemical interactions and mechanical characteristics of composites made of polystyrene reinforced with biochar. Polystyrene-based resin (PBR) was combined with plantain peel-derived biochar in different weight ratios (10%, 20%, 30%, and 40%). The Brinell hardness test, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to evaluate the properties of the composites. The results of the hardness test showed a non-monotonic pattern, with hardness first decreasing at low biochar loadings (10% and 20%), then significantly increasing at 30% biochar. At 40% biochar, the hardness then somewhat dropped, indicating that around 30% filler is the optimal biochar level for hardness. As the biochar loading increased, FTIR measurement showed that hydroxyl groups (-OH) were introduced and that the intensity of carbonyl groups (C = O) increased. According to SEM analysis, a uniform surface was found at lower biochar loadings, but at larger biochar contents, the surface became irregular and rough. In addition to providing insights into the chemical interactions at the interface between the biochar and the polymer matrix, these findings demonstrate the possibility of incorporating biochar to alter the mechanical properties of PBR.

Monodentate Acetate Anion Enhanced Hydrogel Electrolyte for Long-Term Lifespan Zn-Air Batteries.

Flexible Zn-air batteries (FZABs) hold significant promise in diverse application scenarios with high safety and compatibility yet are still impeded by byproduct formation and poor water retention. Here, the neutral hydrogel electrolyte GAHE is engineered by in situ polymerizing acrylamide (AM) in a solution composed of cationic guar gum (CGG) and acetate salts to conquer the above challenges. The acetate anions (OAc-) exert a pH near 7 to effectively inhibit the side reactions triggered by H+. Meanwhile, the monodentate OAc- ions in LiOAc have fast ion diffusion kinetics and form hydrogen bonds between the released carbonyl groups and H2O to further suppress water activity for great side reaction prevention and water retention. Additionally, the in situ polymerization strategy realizes a polymer with high mechanical properties and great electrochemical interfacial stability and further improves the water retention property with hydrophilic groups. Consequently, GAHE gives the FZABs a lifespan of 2050 h at room temperature and 2940 h at -35 °C. This work provides concepts for electrolyte design for water retention and side reaction inhibition properties of aqueous devices.

Program-Modulated Kinetics of Perovskite-Film Growth by Molecular "Thruster"for High-Efficiency and Stable Perovskite Solar Cells.

The rapid reaction between lead iodide (PbI2) and formamidinium iodide (FAI) complicates the fabrication of high-quality formamidinium lead iodide (FAPbI3) films. Conventional methods, such as using nonvolatile small molecular additives to slow the reaction, often result in buried interfacial voids and molecule diffusion, compromising the devices' operational stability. In this study, we introduced a molecular "thruster"-a hypervalent iodine (III) compound with three carbonyl groups and a C--I⁺ bond-that possessescoordination and dissociation abilities, enabling programed modulation of perovskite-film growth kinetics. Initially, the three carbonyl groups coordinate with PbI2 to slow the reaction between FAI and PbI2, preventing δ-phaseformation. As temperature rises, the C--I⁺ bond dissociates, promoting perovskite growth and the dissociated product iodobenzene will promote solvent volatilization, thus avoiding buried interfacial voids. Another product, a carbene compound with eight lone pair electrons sufficiently passivate the undercoordinated Pb2+ defects and anchors at grain boundaries without diffusion. Consequently, the resultant FAPbI3 film displayshigh-quality with enhanced phase purity, compact morphology, and reduced defects. Evidently, 0.062- and 1.004-cm2 pero-SCs achieve power conversion efficiencies (PCEs) of up to 26.06% (25.79% certified) and 24.65%, respectively. This approach alsocontrols perovskite-film growth on plastic substrates, resulting in flexible pero-SCs with an impressive PCE of 25.12%.

Program‐Modulated Kinetics of Perovskite‐Film Growth by Molecular "Thruster" for High‐Efficiency and Stable Perovskite Solar Cells

The rapid reaction between lead iodide (PbI2) and formamidinium iodide (FAI) complicates the fabrication of high‐quality formamidinium lead iodide (FAPbI3) films. Conventional methods, such as using nonvolatile small molecular additives to slow the reaction, often result in buried interfacial voids and molecule diffusion, compromising the devices' operational stability. In this study, we introduced a molecular “thruster”—a hypervalent iodine (III) compound with three carbonyl groups and a C––I⁺ bond—that possesses coordination and dissociation abilities, enabling programed modulation of perovskite‐film growth kinetics. Initially, the three carbonyl groups coordinate with PbI2 to slow the reaction between FAI and PbI2, preventing δ‐phase formation. As temperature rises, the C––I⁺ bond dissociates, promoting perovskite growth and the dissociated product iodobenzene will promote solvent volatilization, thus avoiding buried interfacial voids. Another product, a carbene compound with eight lone pair electrons sufficiently passivate the undercoordinated Pb2+ defects and anchors at grain boundaries without diffusion. Consequently, the resultant FAPbI3 film displays high‐quality with enhanced phase purity, compact morphology, and reduced defects. Evidently, 0.062‐ and 1.004‐cm2 pero‐SCs achieve power conversion efficiencies (PCEs) of up to 26.06% (25.79% certified) and 24.65%, respectively. This approach also controls perovskite‐film growth on plastic substrates, resulting in flexible pero‐SCs with an impressive PCE of 25.12%.

From gem‐Dichlorocyclobutenones to Cyclobutenols: Unveiling a Ruthenium‐Catalyzed Allylic Reduction‐Asymmetric Transfer Hydrogenation Cascade

AbstractCyclobutenones constitute an appealing class of substrates in catalytic asymmetric transformations leading to diversely substituted enantioenriched four‐membered carbocycles, which are eliciting a growing interest in medicinal chemistry. Whilst several synthetically useful enantioselective conjugate addition reactions have been reported, the catalytic enantioselective reduction of the carbonyl group of simple cyclobutenones remains an elusive transformation. Herein, we disclose the discovery of a novel allylic reduction‐asymmetric transfer hydrogenation cascade, catalyzed by a Noyori‐Ikariya ruthenium complex, from readily available gem‐dichlorocyclobutenones, leading to 2‐chlorocyclobutenols with high optical purities, which can be engaged in postfunctionalization reactions enabling access to substituted four‐membered rings.

Repurposing of Empagliflozin as Cardioprotective Drug: An in-silico Approach.

Drug repurposing involves investigating new indications or uses for drugs that have already been approved for clinical use. Empagliflozin is a C-glycosyl compound characterized by the presence of a beta-glucosyl residue. It functions as a sodium-glucose co-transporter 2 inhibitor and is utilized to enhance glycemic control in adults diagnosed with type 2 diabetes mellitus. Additionally, it is indicated for the reduction of cardiovascular mortality risk in adult patients who have both type 2 diabetes mellitus and pre-existing cardiovascular disease. The study's objective revolves around exploring the repurposing potential of a novel SGLT2 inhibitor acting as an antidiabetic drug named Empagliflozin through computational methods, with a specific focus on its interaction with cardioprotective key target proteins. The study was performed by docking the empagliflozin with different target proteins (NHE1- CHP1, BIRC5, GLUT1, and XIAP) by using Autodock, and different values were recorded. The docked files were analysed by the BIOVIA Discovery Studio Visualizer. The in silico analysis conducted in this study examines the binding free energy values of Empagliflozin with key target proteins. Results revealed that NHE1-CHP1 exhibits the lowest binding free energy, followed by BIRC5, GLUT1, and XIAP, with the highest value. This descending order of binding energies suggests varying degrees of effectiveness in binding molecules, with lower energies indicative of more potent biological activity. The analysis underscores the importance of intermolecular interactions, particularly hydrogen bond formations facilitated by oxygen, nitrogen, and carbonyl groups in compound structures. Notably, NHE1-CHP1 demonstrates superior binding interactions with Empagliflozin compared to the other target proteins, highlighting its potential as a cardioprotective agent. These findings offer valuable insights into the therapeutic possibilities of Empagliflozin in cardioprotection, indicating promising avenues for further research and development in this domain.

Spatial Conformation Engineering of Aromatic Ketones for Highly Efficient and Stable Perovskite Solar Cells.

Carbonyl-containing materials employed in state-of-the-art hybrid lead halide perovskite solar cells (PSCs) exhibit a strong structure-dependent electron donor effect that predominates in defect passivation. However, the impact of the molecular spatial conformation on the efficacy of carbonyl-containing passivators remains ambiguous, hindering the advancement of molecular design for passivating materials. Herein, we show that altering the spatial torsion angle of aromatic ketones from twisted to planar configurations, as seen in benzophenone (BP, 27.2°), anthrone (AR, 15.3°), and 9-fluorenone (FO, 0°), leads to a notable increment of the electron cloud density around the carbonyl group, thus improving the passivation ability for lead-based defects. Consequently, the PSC performance also relies on the torsion angle of the aromatic ketones, with the coplanar FO-based PSC achieving a highest power conversion efficiency (PCE) of 25.13% and retaining 92% of its initial efficiency after 1000 h of operation at the maximum power point under continuous 1-sun illumination (ISOS-L-1I). Moreover, a perovskite mini-module (14.0 cm2) containing FO exhibits a PCE of 20.19%. Our findings highlight the influence of molecular conformation on the passivation effect of the carbonyl group, offering deeper insight into the design and development of aromatic ketones as passivators for highly efficient and stable PSCs.

Rationalizing the crosslinking reaction of an α,β unsaturated carbonyl of clovamide from Adansonia digitata L. and the cysteine residue of HIV-1 integrase enzyme

In this study, clovamide was identified for the first time in Adansonia digitata L. fruit pulp using the UHPLC-q-TOF-MS. The inhibition potential of the naturally occurring clovamide, specifically in the SE and SZ configurations and their yet to be identified enantiomers (RE and RZ) on HIV-1 integrase (HIV-1 INT) were investigated using molecular docking studies. The results revealed that all the four stereoisomers of clovamide bind to key residues crucial for the catalytic activity of HIV-1 INT (ASP64, ASP116 and GLU152) as well as other significant residues including, LYS152 and LYS159. This indicates that clovamide has the potential to inhibit this enzyme and possibly slow down HIV-1 replication. Interestingly, the docking results showed that CYS65 was in close proximity to ASP64, allowing nearly all isomers of clovamide to interact with this residue. This suggested a potential crosslinking reaction via Michael addition between clovamide and CYS65. The consistent proximity of all ligands to CYS65 in the studied protein throughout the entire molecular dynamics simulation period also showed the potential of permanent covalent bonds formation via a Michael addition reaction. Density functional theory modelling confirmed that the α,β-unsaturated carbonyl group of clovamide and cysteine interact, forming a clovamide-integrase adduct, potentially leading to irreversible inhibition of HIV-1 INT. This study not only highlighted the potential of clovamide as an inhibitor of HIV-1 INT but also demonstrated that clovamide possesses various functional groups that can be exploited in different biological activity studies. Findings of this study suggest that clovamide and its stereoisomers could be valuable candidates for the development of new antiretroviral therapies, offering a novel approach to overcoming drug resistance through multiple inhibition mechanisms.

Enantioselective Excited-State Nazarov Reaction: A Relay Strategy of Electrocyclization and Parallel Kinetic Resolution.

We report herein the enantioselective photoinduced Nazarov reaction using a relay strategy of an electrocyclization, followed by parallel kinetic resolution (PKR). No enantioselectivity was observed during electrocyclization due to weak coordination between chiral ligands and the substrate's carbonyl group. However, PKR was successfully achieved in the deprotonation step with a bifunctional chiral thiourea ligand. Regioselective deprotonation, controlled by the chiral N,N-dimethyl amine motif, produced cis-6,5,6-fused tricyclic stereoisomers with high ee and yields.

Improving wood surface wettability through gas-phase ozone treatment of air-dry wood

An increase in wood free surface energy enhances the wettability of wood surfaces, leading to better interaction with water-based coatings. This study investigated the effect of gas-phase ozonation on the wettability of spruce, thermo-modified pine, and birch woods. The effects of the treatment were evaluated by measuring the water contact angle and the Cobb value on the wood sample surfaces, and by determining the surface free energy of the wood surfaces using the Owens, Wendt, Rabel, and Kaelble (OWRK) calculation method. Furthermore, water absorption and evaporation rates were assessed through water immersion and subsequent drying of the wood samples. The results indicated that ozone treatment increased the surface energy, and especially its polar component, thus accelerating water spreading and absorption on the wood surfaces. The most probable cause of the observed effects is the formation of new carbonyl and carboxyl groups resulting from reactions of the ozone with the wood surface. The findings suggest that the ozone treatment technique can enhance spreading, absorption, and adhesion of water-based adhesives and coatings to wood surfaces. This research may facilitate the development and use of new environmentally friendly water-based adhesives and coatings.

Hepatic GPx1 and GIT1 expression altered by ethanol exposure during third trimester-equivalent development

Background Ethanol (EtOH) exposure throughout gestation and breastfeeding leads to multiple adverse outcomes in the hepatic system. Under oxidative stress, alterations in the liver are related to the inhibition of induced nitric oxide synthase activity in sinusoidal cells as a consequence of low expression of G-protein-coupled receptor (GPCR)-kinase interacting (GIT1). Here, we hypothesized that both glutathione peroxidase 1 (GPx1) and GIT1 could be altered by EtOH exposure during the third trimester of human equivalent development. Methods We exposed rats during the third trimester equivalent [postnatal days (PD) 2-8] to moderate levels of maternal EtOH (20%). GPx1 and GIT1 expression was detected by western blotting, and the antioxidant activity of glutathione peroxidase GPx and the concentration of hepatic carbonyl groups (CG were determined by spectrophotometry. Serum biochemistry parameters such as alanine aminotransferase (ALT), glucose (gluc), cholesterol (chol), and triglycerides (TG) were also measured. Results We found that ethanol decreased both GIT1 and GPx1 selenoprotein expression, affecting GPx antioxidant activity and increasing protein oxidation. Conclusions These results demonstrate for the first time that the GPx antioxidant system altered by EtOH exposure during the third trimester of development is related to a parallel decrease in GIT1 expression [1].

Three‐Component Alkylsulfonylation of 1‐Acryloyl‐2‐cyanoindoles with Hantzsch Esters through Sulfur Dioxide Insertion

A three‐component alkylsulfonylation/cyclization/ hydrolysis relay reaction of 1‐acryloyl‐2‐cyanoindoles with 4‐alkyl Hantzsch esters and Na2S2O5 to access a series of alkylsulfonyl pyrrolo[1,2‐a]indolediones derivatives involving in situ sulfur dioxide insertion is established. With this method, a variety of primary and secondary alkyl radicals can be used for trapping sulfur dioxide and in situ formed corresponding alkylsulfonyl radical intermediates, followed by alkyl sulfonyl radical addition, cyclization and hydrolysis. In addition, this reaction goes through once selective cleavage of σ carbon‐carbon bond and following successively formation of three new chemical bonds, in which cyano group acts as the dual roles, including the radical acceptor and carbonyl source.

Enhancing Flexibility, Long-Term Stability, and Efficiency in Full Air Fabricated Perovskite Solar Cells via Multifunctional Fluorinated Polyurethane Additives.

Perovskite films often suffer from surface and grain boundary defects, including uncoordinated ions, lattice distortions, and dangling bonds, coupled with lattice distortions due to solvent volatilization anisotropy and the thermal expansion coefficient. Such defects severely compromise both the photovoltaic efficiency and long-term solar cell stability. Here, fluorinated polyurethane (FPU) was synthesized and introduced into the perovskite precursor as a multifunctional additive. Excess Pb2+ ions interact with the carbonyl group (C═O) of FPU, thereby reducing nonradiative recombination. The perovskite and FPU form various hydrogen bonds via MA+ with F and -NH with -I. This multiplies the passivation of grain boundary defects, increases grain size, reduces defect density, releases residual lattice stress, and facilitates charge transport. Accordingly, the power conversion efficiency of the FPU-modified perovskite solar cells (PSCs) on rigid substrates and flexible substrates reached 21.18 and 17.76%, respectively. Notably, the long-chain C-F compound, which constructs a moisture-resistant barrier, could inhibit moisture corrosion in the perovskite films. After 2000 h of storage at ambient temperature in dark, the PSCs's initial efficiency still remained 82%. Additionally, after it undergoes 300 bending cycles (r = 0.7 cm), the device maintains 92.4% of its initial efficiency.

Diastereoselective Substitution Reactions of Acyclic Acetals Controlled by Remote Participation of an Acyloxy Group.

A remote carbonyl group up to six atoms away from the acetal group can induce 1,2-asymmetric induction in nucleophilic substitution reactions of acyclic acetals. Isolation of a cyclic carbonate under Lewis acidic conditions and computational studies suggested that the remote carbonyl group participated through the formation of a cyclic dioxocarbenium ion intermediate. The stereochemical outcomes depended on the size of the alkyl substituent and that of the nucleophile employed.

Chromium Isotope Fractionation During the Removal of Hexavalent Chromium by Oak-based Biochar

Chromium, especially in its hexavalent form (Cr(VI)), poses significant health risks due to its carcinogenic properties. Emerging research suggests that biochar, a carbon-rich material derived from biomass pyrolysis, holds promise as an effective and sustainable solution for Cr(VI) remediation. Biochar's unique physicochemical properties, such as its high surface area, porous structure, and functional groups, contribute to its exceptional adsorption capacity for metals. In a series of batch experiments with varying durations, an oak-based biochar was exposed to a 48 mg∙L⁻1 Cr(VI) solution. The results demonstrate that the biochar effectively removed 99% of the Cr(VI) after 100 hours, with a removal capacity greater than 5 mg∙g⁻1. Fourier transform infrared (FTIR) spectroscopy suggests that the removal of Cr(VI) involved aliphatic and aromatic C-H bonds. X-ray photoelectron spectroscopy (XPS) also indicated the role of aliphatic groups in the removal process and suggested the involvement of carbonyl groups. XPS analysis also detected both Cr(III) and Cr(VI) on the surface of the biochar, indicating the occurrence of reduction and sorption processes. The presence of Cr(III) and Cr(VI) was further confirmed at the Canadian Light Source (CLS) synchrotron facility using X-ray absorption near edge structure (XANES) spectroscopy. Cr isotope analysis showed an increase in δ⁵³Cr as the concentration of Cr in solution decreased, indicating Cr(VI) reduction. The isotope data followed a Rayleigh curve with a kinetic fractionation ε53Cr of -1.33 ‰, highlighting that Cr stable isotopes can effectively be used as an indicator of biochar-Cr reactions.

Organic modes of occurrence and evolution mechanism of germanium and lithium in coal: Insights from density functional theory

Critical elements in coal, such as Ge and Li, recently have attracted attention due to their economic significance. Modes of occurrence of these critical elements are academically and practically important, because they can not only provide evidence for sources of elements and minerals in coal and regional geological background information, but also help with design of recovery methods. However, conventional analytical methods are unable to observe precisely the organic binding sites of Ge and Li in coal, and this limits the understanding of their enrichment mechanism and the improvements for recovery techniques. In this study, organic modes of occurrence and evolution mechanism of Ge4+ and Li+ were investigated at the atom level by constructing molecular models of Ge- and Li-rich coals combined with density functional theory (DFT) methods. The solid-state 13C nuclear magnetic resonance spectroscopy (NMR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and helium pycnometry analyses indicate that the molecular formulas of Ge- and Li-rich coals are C166H162N2O32 and C153H174N2O24S, respectively. The DFT analysis reveals that the binding sites for Ge4+ in Ge-rich coal are located near the carboxyl group (-COOH) and the pyrrole ring, while those for Li+ in Li-rich coal are near the carbonyl group (-C=O) and the pyrrole ring. The Ge4+ is immobilized in the Ge-rich coal molecular model through coordination bonds with the O atom in the -COOH and the C atom in the pyrrole ring, while being away from the N atom in the pyrrole ring. Li+ forms a coordination bond with the O atom in the -C=O and additional coordination bond with the nearby hydroxyl group during binding to the pyrrole ring. The impact of coal rank on the organic modes of occurrence of Ge4+ and Li+ was investigated using Wender coals of different ranks, which were one of the earliest proposed coal models. At the lignite stage, oxygen-containing functional groups and aromatic rings show a strong binding ability to Ge4+ and Li+, facilitating their enrichment in coals. Along with coal rank advance to bituminous coal, the reduction of oxygen-containing functional groups (e.g., -COOH and -C=O) and the relatively low condensation of aromatic rings decrease binding sites for Ge4+ and Li+, and the binding ability also decline, resulting in a decrease in their concentration. In anthracite stage, highly condensed aromatic rings provide binding sites for Ge4+ and Li+. The strong binding ability of aromatic rings to Ge4+ indicates that it is probably enriched in anthracite, whereas Li+ is difficult to enrich owing to its relatively weak binding ability to aromatic rings. The low content of oxygen-containing functional groups in anthracite reduces their effect on the organic modes of occurrence of Ge4+ and Li+. This study elucidates the organic modes of occurrence and evolution mechanism of Ge4+ and Li+ from the perspective of coal structure, providing fundamental insights for future research on the interaction between organic and inorganic matter within coal.

Recent Progress in Isolating and Purifying Amide Alkaloids from their Natural Habitats: A Review

: Alkaloids are nitrogen-containing chemical compounds found in nature. Many alkaloids are heterocyclic in nature. They are nitrogen-based organic compounds with the nitrogen atoms enclosed in a heterocyclic ring. The chemical "pro alkaloid" is derived from the alkyl amines in it. Many ancient people, long before the advent of organic chemistry, recognized that many of these substances have measurable effects on the body's physiological functions. Alkaloids are a type of natural substances that are classified as secondary metabolites. Many different types of organisms create alkaloids, which are a class of natural products. Alkaloids showed antifungal, local anesthetic, anti-inflammatory, anticancer, analgesic, neuropharmacologic, antimicrobial, and many other activities. Amines, as opposed to alkaloids, are the more common classification for naturally occurring compounds that contain nitrogen in the exocyclic position (such as mescaline, serotonin, and dopamine). An amide molecule has a nitrogen atom that is chemically bound to a carbon atom in the carbonyl group. The -oic acid ending of the corresponding carboxylic acid is converted to -amide to form the correct nomenclature for an amide. This article offers an overview of numerous techniques for extracting, separating, and purifying alkaloids for use in natural medicine.