Aliphatic Groups Research Articles

Optimization of crude rotenone oil extraction from birbira plant (Milletia ferruginea) seed by Soxhlet and maceration methods

The extraction of active compounds from plant materials is one of the most critical processes in the commercial development of natural products for pharmaceutical, herbicide or pesticide production. The focus of this study was extraction of crude rotenone oil (CRO) from Birbira plant (Milletia ferruginea) seed. The extraction was done using maceration anda Soxhlet extractor using organic solvents, such as ethanol, hexane, and chloroform. For the efficient extraction of crude rotenone oil from Birbira plant seed the effect of parameters, such as extraction method, solvent type, extraction time and size of crushed Birbira seed were investigated. Based on the experimental results obtained Soxhlet extraction method was more efficient (41.6% CRO yield) compared to the maceration extraction method (25.1 % CRO yield). The extraction results for both Soxhlet and maceration methods indicated that chloroform is more efficient compared to ethanol and hexane solvents. On the other hand, the effects of crashed seed size and extraction time on the % CRO yield were also investigated. The results showed that medium size (0.1–0.35 mm) for both Soxhlet and maceration extraction was the optimum size leading to the highest % CRO yield compared to fine and coarse ground seed size. The highest % CRO yield was obtained during 4 to 5 h of Soxhlet extraction and 25 to 30 h of maceration extraction method. Therefore, the Soxhlet extraction method is the fastest and efficient method for the extraction of CRO from plant materials. The characterization of Birbira seed powder and CRO was done with FTIR and Rheology test equipment. The FTIR result revealed that CRO is composed of aliphatic, olefin, polyphenol and alcohol functional groups, in which polyphenol functional groups are the most essential flavonoid components available in crude rotenone oil.

Biogenic Origin of Fe-Mn Crusts from Hydrothermal Fields of the Mid-Atlantic Ridge, Puy de Folles Volcano Region

Ferromanganese formations are widespread in the Earth’s aquatic environment. Of all the mechanisms of their formation, the biogenic one is the most debatable. Here, we studied the Fe-Mn crusts of hydrothermal fields near the underwater volcano Puy de Folles (rift valley of the Mid-Atlantic Ridge). The chemical and mineralogical composition (optical and electron microscopy with EDX, X-ray powder diffraction, X-ray fluorescence analysis, Raman and FTIR spectroscopy, gas chromatography—mass spectrometry (GC-MS)) and the magnetic properties (static and resonance methods, including at cryogenic temperatures) of the samples of Fe-Mn crusts were investigated. In the IR absorption spectra, based on hydrogen bond stretching vibrations, it was concluded that there were compounds with aliphatic (alkane) groups as well as compounds with double bonds (possibly with a benzene ring). The GC-MS analysis showed the presence of alkanes, alkenes, hopanes, and steranes. Magnetically, the material is highly coercive; the blocking temperatures are 3 and 13 K. The main carriers of magnetism are ultrafine particles and X-ray amorphous matter. The analysis of experimental data allows us to conclude that the studied ferromanganese crusts, namely in their ferruginous phase, were formed as a result of induced biomineralization with the participation of iron-oxidizing and iron-reducing bacteria.

Revolutionizing Bone Regeneration with Grinder-Based Dentin Biomaterial: A Systematic Review.

Bone tissue regeneration is a critical aspect of dental surgery, given the common occurrence of bone resorption leading to alveolar bone defects. The aim of this paper was to conduct a systematic review to provide a comprehensive summary of the evidence regarding the regenerative properties of dentin biomaterial. This systematic review was conducted through comprehensive searches in the PubMed, Scopus, and Web of Science databases, as well as an extensive exploration of the gray literature sources, including WorldCat, The New York Academy of Medicine Library, and Trip Database, following the established PRISMA protocol. Keywords such as tooth, dentin, grinder, and autograft guided the search, with a focus on a standardized procedure involving dentin grinders within laboratory, experimental, and clinical settings. Initially, a pool of 1942 articles was identified with 452 duplicates removed. An additional 1474 articles were excluded for not aligning with the predefined topics, and three more were excluded due to the unavailability of the full text. Ultimately, 13 articles met the strict inclusion criteria and were included in the review. The chemical composition of the dentin particles was similar to natural bone in terms of oxygen, carbon, calcium, phosphorus, sodium, and magnesium content, as well as in terms of the Ca/P ratio. In addition, the dentin also contained amide I and amide II structures, as well as aliphatic and hydroxyl functional groups. The chemically treated dentin was free of microorganisms. The dentin had characteristic tubules that opened after chemical treatment. At the cellular level, dentin released bone morphogenetic protein 2, induced significant cell growth, and stimulated the reorganization of the fibroblast cytoskeleton. Most clinical studies have focused on alveolar bone regeneration. After the transplantation of demineralized dentin particles, studies have observed new bone formation, a reduction in residual bone, and an increase in connective tissue. Clinical reports consistently indicate uncomplicated healing and recovery post-transplantation. However, there is a notable gap in the evidence concerning complication rates, patient-reported outcomes, and the presence of pro-inflammatory factors. In conclusion, dentin biomaterial emerges as a versatile bone substitute, demonstrating high biocompatibility and ease of acquisition. The preservation of its internal structure containing organic matter and growth factors enhances its potential for effective bone regeneration. Particularly, in dental surgery, dentin-derived materials present a promising alternative to traditional autologous bone autografts, offering the potential to reduce patient morbidity and treatment costs.

Changes in Soil Aggregate Carbon Components and Responses to Plant Input during Vegetation Restoration in the Loess Plateau, China.

Vegetation restoration is an effective measure to cope with global climate change and promote soil carbon sequestration. However, during vegetation restoration, the turnover and properties of carbon within various aggregates change. The effects of plant source carbon input on surface soil and subsurface soil may be different. Thus, the characteristics of carbon components in aggregates are affected. Therefore, the research object of this study is the Robinia pseudoacacia forest located in 16-47a of the Loess Plateau, and compared with farmland. The change characteristics of organic carbon functional groups in 0-20 cm, 20-40 cm, and 40-60 cm soil layers were analyzed by Fourier near infrared spectroscopy, and the relationship between the chemical structure of organic carbon and the content of organic carbon components in soil aggregates was clarified, and the mechanism affecting the distribution of organic carbon components in soil aggregates was revealed in the process of vegetation restoration. The results show the following: (1) The stability of surface aggregates is sensitive, while that of deep aggregates is weak. Vegetation restoration increased the surface soil organic carbon content by 1.97~3.78 g·kg-1. (2) After vegetation restoration, the relative contents of polysaccharide functional groups in >0.25 mm aggregates were significantly reduced, while the relative contents of aromatic and aliphatic functional groups of organic carbon were significantly increased. The opposite is true for aggregates smaller than 0.25 mm. (3) With the increase in soil depth, the effect of litter on organic carbon gradually decreased, while the effect of root input on the accumulation of inert carbon in deep soil was more lasting.

Visible light-driven decarboxylative alkylation of azomethine imines with carboxylic acids

The alkylation of cyclic five-membered azomethine imines with carboxylic acids proceeds under irradiation with 400 nm light using a dual catalytic system consisting of 9-arylacridine and tetrabutylammonium decatungstate. Azomethine imines containing aromatic, heterocyclic and aliphatic groups are suitable for the process providing pyrazolidin-3-ones in 42–98% yields.

Exploring molecular fragments for fraction unbound in human plasma of chemicals: a fragment-based cheminformatics approach

ABSTRACT Fraction unbound in plasma (f u,p) of drugs is an significant factor for drug delivery and other biological incidences related to the pharmacokinetic behaviours of drugs. Exploration of different molecular fragments for f u,p of different small molecules/agents can facilitate in identification of suitable candidates in the preliminary stage of drug discovery. Different researchers have implemented strategies to build several prediction models for f u,p of different drugs. However, these studies did not focus on the identification of responsible molecular fragments to determine the fraction unbound in plasma. In the current work, we tried to focus on the development of robust classification-based QSAR models and evaluated these models with multiple statistical metrics to identify essential molecular fragments/structural attributes for fractions unbound in plasma. The study unequivocally suggests various N-containing aromatic rings and aliphatic groups have positive influences and sulphur-containing thiadiazole rings have negative influences for the f u,p values. The molecular fragments may help for the assessment of the f u,p values of different small molecules/drugs in a speedy way in comparison to experiment-based in vivo and in vitro studies.

Comprehensive crosslinking strategy using fluorinated azide to enhance the thermal stability of ceramic-coated separators for Li-ion batteries

Enhancing the thermal and mechanical stabilities of ceramic-coated separators (CCSs) is required for high-safety lithium-ion batteries (LIBs). As both the thickness and areal mass of ceramic coating layers (CCLs) have reduced, various strategies have been developed to overcome the limitations of conventional ceramics and polymeric binders. In this regard, we suggest a comprehensive photocrosslinking approach to form fully crosslinked CCLs using a new fluorinated azide binder that can readily react with aliphatic functional groups in any component of CCSs. When a small amount of azide binder is added to a CCL slurry consisting of Al2O3 particles and a poly(acrylic acid) (PAA) binder, short UV irradiation can lead to inter- and intramolecular crosslinking points within the polyethylene (PE) separator, between the PE separator and the PAA binder, and within the PAA binders in the CCL. Consequently, the thermal stability and the adhesive strength of crosslinked CCS (X-CCS) can be significantly improved compared to the control CCS without azide. Moreover, a LiNi0.6Co0.2Mn0.2O2/graphite cell with X-CCS exhibited a comparable cycle life to that of the PE separator and non-crosslinked CCS. Furthermore, because UV illuminators are easily added to conventional fabrication processes, this strategy is a simple but effective approach for advancing high-safety LIBs.

Electroactive and Self‐healing Polyurethane Doped Tin Oxide Interlayers for Efficient Organic Solar Cells†

Comprehensive SummaryTin oxide (SnO2) has been widely used as an electron transport layer (ETL) in optoelectronic devices. However, there are numerous surface or bulk defects in SnO2, working as charge recombination centers to degrade device. Here, an electroactive and self‐healing polyurethane (PHNN) was designed by integrating conjugated unit – naphthalene diimide (NDI) into a typical polyurethane backbone. Numerous hydrogen bonds and π interactions in PHNN work as non‐covalent interactions to endow this polymer with superior self‐healing properties. PHNN contains lots of aliphatic amine and carbonyl groups, which effectively passivate the defects in SnO2. The π stacking of NDI units will facilitate electron delocalization, endowing PHNN with electrical activity compared with traditional polyurethane. Doping SnO2 with PHNN can improve the conductivity and reduce the work function of SnO2 layer, which is conducive to efficient charge extraction and transport. Using PHNN doped SnO2 as ETL for PM6: Y6 and PM6: BTP‐eC9 based inverted organic solar cells can achieve a high efficiency of 17.16% and 17.51%, respectively. Devices containing doped SnO2 ETL show significantly improved efficiency and stability. Thus, the electroactive polyurethane doped SnO2 interlayers show high performance interfacial modification to align energy‐levels in solar cell devices, which have promising applications in organic electronics.

Study on using waste biomass as carbon reducing agent in industrial silicon smelting

In this study, seven types of biomass (coffee husk, macadamia husk, peanut husk, rice husk, rice straw, tobacco straw, and cotton straw) were carbonized at temperatures ranging from 300 °C to 1000 °C. This study explored the potential of these biomass samples as carbon reducing agents for industrial silicon and compared them with charcoal in terms of their proximate analysis, electrical resistivity, and apparent activation energy of the reaction. The results indicated that as the pyrolysis temperature increased, the oxygen content and aliphatic functional groups in biochar gradually decreased, as did the volatiles content, while the proportions of fixed carbon and ash increased. The resistivity decreased upon the removal of volatiles and an increase in the degree of graphitization. At 600 °C, the fixed carbon content of all biochar exceeded 65%, and the fixed carbon content of macadamia husk biochar reached 91.32%, which was higher than that of charcoal (81.44%), the maximum specific surface area was 335.706 m2/g, which was much higher than that of charcoal (5.705 m2/g). Thermogravimetric analysis and kinetic analysis indicated that coffee husk had better reactivity than charcoal. The gasification reactivity of coffee husk was R = 3.1949%/min °C, which was higher than that of charcoal (0.7930 %/min °C). The apparent activation energy during the coking reaction stage was 51.86 kJ/mol, which was lower than that of charcoal (98.9 kJ/mol). Overall, biochar had a suitable fixed carbon and electrical resistivity at 600 °C and can be used as a carbon reducing agent for industrial silicon, among them, macadamia husk with high fixed carbon and coffee husk with high reactivity have greater application potential.

Mechanistic study of carbon dioxide sequestration technology using molecular simulations to assess the adsorption of methane and carbon dioxide by different functional groups

To investigate the characteristics of CO2 and CH4 adsorption across various functional groups and to clarify their thermodynamic attributes, slit models of functional groups with different pore sizes and moisture contents were constructed using the Materials Studio software program. The analysis focused on the characteristics of CO2 and CH4 adsorption in six distinct models comprising different functional groups. The results showed that the adsorption activities of the six functional groups followed the order –CHO>–COOH>–OH>-O-CH3 > –CH3 > –CH2CH3. The average adsorption heat of the oxygen-containing functional groups exceeded that of the aliphatic groups for both the single- or two-component injections of CO2. As the moisture content increases, the maximum adsorption capacity of CH4 in the slit models with –CH2CH3, −O-CH3, –COOH, and –OH functional groups show a significant decreasing trend when injecting CH4 with two components. The absolute value of the adsorption energy of CO2 and CH4 decreases with increasing pore size. In the slit models with –CHO and –COOH functional groups, multiple peaks appear in the adsorption energy of CO2, indicating a greater number of adsorption sites. For the two-component injection of CO2 and CH4, the entropy of CO2 in each functional group was minimized at a pore size of 1 nm.

Molecular Hydrogen Formation via Vibrational Excitation of Partially Superhydrogenated Pyrenes

While polycyclic aromatic hydrocarbons (PAHs) are now accepted to be abundant in interstellar space, the abundance and influence of superhydrogenated PAHs (HPAHs) in the interstellar medium (ISM) are still under investigation. HPAHs may act as catalysts for or reactants in small-molecule formation via hydrogen abstraction reactions, H2 evaporation, and carbon skeleton fragmentation. Here, we present a gas-phase infrared (IR) action spectroscopy study of the HPAH 4, 5, 9, 10-tetrahydropyrene (THP; C16H14), performed at the Free Electron Lasers for Infrared eXperiments facility. IR action spectroscopy was performed on the THP cation, protonated THP, and their fragments produced by collision-induced dissociation in the range from 600 to 1800 cm−1. Calculated IR spectra, at the density functional theory level, agree with experimental IR spectra to a high degree and were utilized to determine molecular structures of the HPAH fragments. Molecular dynamics simulations compared with experimental mass spectra reveal favorable HPAH fragmentation pathways. Molecular hydrogen (H2) is observed to be a primary fragment of [THP+H]+ with superhydrogenated duo groups. This contrasts the notion that HPAHs typically undergo carbon skeleton fragmentation leading to C x H y formation. These observations show that lowered symmetry and duo or trio aliphatic groups on HPAHs uniquely change their IR spectra, stability, and fragmentation patterns. As a result, these species may contribute to H2 formation in the ISM.

Study on microstructure evolution and oxidation kinetics in Coal-Oil Symbiosis

Differences in the spontaneous combustion mechanism characteristics of Coal-Oil Symbiosis (COS) significantly affect coal mines' safety management and ecological environment maintenance. Accordingly, this study aims to investigate COS's macroscopic and microstructural characteristics with different oil mass percentage using simultaneous thermal analysis, low-temperature N2 adsorption, scanning electron microscopy (SEM), and in-situ Fourier transform infrared spectroscopy (FTIR). The results showed that with the increase of oil mass percentage, the COS displayed the weakening of oxygen absorption and the advance of some characteristic temperatures, and 11.5 °C advanced the maximum weight loss temperature on average. For the 25 % oil sample, the ignition temperature was 9.5 °C lower than that of the raw coal. Additionally, the apparent activation energy of the high oil mass percentage sample was significantly reduced in the pyrolysis and combustion stages, and when the oil mass percentage was 25 %, the activation energies of the two stages decreased by 89 % and 60.65 %, respectively. Compared to raw coal, COS exhibits fewer macropores and surface pores covered by oil, which limits oxygen adsorption. Moreover, COS with higher oil mass percentage had an increase in hydroxyl and aliphatic hydrocarbon groups, and the CH3 + CH2 content of COS increased by 69.2 % on average, providing more active groups, thereby promoting spontaneous combustion. This study provides an important reference and theoretical support for further understanding the structural evolution and oxidation kinetic behavior of COS, contributing to disaster prevention and ecological environmental protection in coal-oil coexistence mining areas.

Experimental investigation of kerogen structure and heterogeneity during pyrolysis

Kerogen in shale microstructure plays a vital role in hydrocarbon generation, retention and accumulation. However, characterization of kerogen structure is challenging arguably due to a complex microporous structure and chemical heterogeneity. Thus, the role of kerogen molecular structure in controlling porosity and its heterogeneity, as well as its evolutionary processes, remains unclear. In this study, we investigate the chemical and pore structure of heated kerogen samples by employing a range of characterization tools including gas adsorption experiments, high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR) spectroscopy, and laser Raman experiments for a broad range of pyrolysis temperatures (420–850 °C). Multifractal theory and peak fitting techniques were used to evaluate the controlling mechanisms of kerogen pore structure and heterogeneity. The results suggest that with increasing thermal maturity, the content of oxygen functional groups and long-chain aliphatic groups in kerogen significantly decreases, while the length of aromatic fringes increases and gradually becomes oriented. Furthermore, with increasing thermal maturity, the pore volume of kerogen exhibits a non-monotonic trend, i.e., a decrease, followed by an increase, and then finally a decrease. This is primarily influenced by processes such as hydrocarbon production weakening, secondary hydrocarbon cracking, and carbonization. The heterogeneity and dispersion of meso to macro-sized pores in kerogen increase with temperature, while the connectivity gradually decreases. The chemical structure and spatial distribution of kerogen significantly affect the heterogeneity, connectivity, and dispersion of meso to macro-sized pores. Specifically, high aromaticity, structural disorder, and short aliphatic chains result in enhanced heterogeneity and dispersion of meso to macro-sized pores, reducing pore connectivity. This study thus contributes to a deeper understanding of the evolution of organic matter pores.

Efficient synthesis of novel 1,10 phenanthroline-substituted imidazolium salts: Exploring their anticancer applications

This study reports a new series of 1,10-phenanthroline-substituted imidazolium salts (1a–f), examining their design, synthesis, structure and anticancer activities. The structures of these salts (1a–f) were characterized using 1H, 13C NMR, elemental analysis, mass spectrometry and Fourier transform infrared (FT-IR) spectroscopies. The salts' cytotoxic activities were tested against cancer cell lines, specifically MCF-7, MDA-MB-231 and non-tumorigenic MCF-10A mammary cells. The study compared the impact of aliphatic and benzylic groups in the salts’ structure on their anticancer activity. Screening results revealed that compound 1c, in particular, showed promising inhibitory activity against the growth of MDA-MB-231 breast cancer cells, with an IC50 value of 12.8 ± 1.2 μM, indicating its potential as a chemotherapeutic agent. Cell apoptosis analysis demonstrated a tendency for compound 1c to induce early apoptosis in breast cancer cells. The stability/aquation of compound 1c was investigated using 1H NMR spectroscopy and its binding modes with DNA were explored via UV–Vis spectroscopy. Additionally, the study investigated the interaction residues and docking scores of compound 1c and the reference drug doxorubicin against Bax and Bcl-2 proteins using molecular docking.

Predicting antimicrobial properties of lignin derivatives through combined data driven and experimental approach

Meta-analysis, experimental and data-driven quantitative structure–activity relationship (QSAR) models were developed to predict the antimicrobial properties of lignin derivatives. Five machine learning algorithms were applied to develop QSAR models based on the ChEMBL, a public non-lignin specific database. QSAR models were refined using ordinary-least-square regressions with a meta-analysis dataset extracted from literature and an experimental dataset. The minimum inhibition concentration (MIC) values of compounds in the meta-analysis dataset correlate to classification-based descriptors and the number of aliphatic carboxylic acid groups (R2 = 0.759). Comparatively, QSARs derived from the experimental datasets suggest that the number of aromatic hydroxyl groups were better predictors of Bacterial Load Difference (BLD, R2 = 0.831) for Bacillus subtilis, while the number of alkyl aryl groups were the strongest correlation in predicting the BLD (R2 = 0.682) of Escherichia coli. This study provides insights into the type of descriptors that correlate to antimicrobial activity and guides the valorization of lignin into sustainable antimicrobials for potential applications in food preservation, fermentation, and other industrial sectors.

Carbon stocks in Planosols along a rainfall gradient in Northeast Brazil

Planosols have sandy-textured surface horizons that abruptly cover a dense subsoil with high clay content, which usually limits drainage and influences soil moisture. Here, we investigated changes in C storage through the pedogenic horizons of soil profile, including detailed sampling of A and B horizons along a transect to cover rainfall variation (584–1130 mm year−1) and soil cover of Planosols, including dry land areas in Northeast Brazil. The soil profile located under highest precipitation and with the greatest pedogenic development (150 cm) showed the largest C stock (101.91 Mg/ha), surpassing estimates of other soil classes. In addition, our results suggest that soil cover and pedogenesis impact C storage in Planosols. An average of 64 % of C is stored in subsurface horizons that present abundant clay fraction; thus, the dynamics of subsurface soil organic carbon (SOC) appear to be more controlled by soil features than by climate. Values of δ13C indicated the predominance of C3 plant, except in area with sugarcane cultivation (C4 plant). Changes in C distribution within the horizon suggest changes in degree of decomposability of soil organic matter (SOM), mainly in A1 and B1 layers, with A horizon richer in labile compounds. δ15N values indicated that N dynamics differ in the gradient. The thermal analyses showed that around 70 % or more of humin fraction is composed of structures more resistant to degradation, suggesting that C stock in Planosols has relative stability. However, in driest part of the climate transect, SOM may be more vulnerable to losses due to the large relative quantity of aliphatic groups in soil surface and subsurface. This work provides insights into the mechanisms the determine C storage distribution in tropical Planosols and contributes to appropriate use and management of these soils to ensure the valuable ecosystem service of C storage.

Effect of 4-[2-(dimethylamino)ethyl]morpholine, and N,N-dimethylbenzylamine on urethane formation - A theoretical study

The formation of urethane through the reaction between phenyl isocyanate (PhNCO)–butan-1-ol (BuOH) was investigated. The reactions, without and in the presence of 4-[2-(dimethylamino)ethyl]morpholine (DMAEM), and N,N-dimethylbenzylamine (DMBA) catalysts have been examined using the BHandHLYP/6-31G(d) and G3MP2BHandHLYP levels of theory. The SMD implicit solvent model has been applied to simulate the solvent effect. As the reaction mechanism contains protonation steps, therefore the proton affinity for the selected catalysts has also been determined. Furthermore, the two selected catalysts have been compared. DMAEM contains different cyclic and aliphatic nitrogen functional groups, while the DMBA contains only aliphatic catalytic site. All in all, the presence of the catalysts significantly changes the reaction mechanism and the energetics of the reaction compared to the catalyst-free case. It was found that the cyclic amine has a slightly greater effect on the energetics of the catalytic reaction compared to the aliphatic one.

Insight into carbon structures and pyrolysis behaviors of coal from the 13C CP/MAS NMR spectra

Carbon structures play an important role in the pyrolysis behavior of coal. Solid-state 13C nuclear magnetic resonance (NMR) spectroscopy is a powerful nondestructive technique for characterizing the carbon skeleton structures in coal. In this study, the carbon type distribution, lattice parameters, and chemical bond concentrations of six coal samples with different Vdaf values were investigated using 13C CP/MAS NMR spectra. Typical TGA and Py-GC-MS methods were utilized to obtain information on weight loss and pyrolysis products of the coals. The aromaticity of coal was determined by an adjustment of the apparent area ratio in the 13C CP/MAS NMR spectra, which shows promising potential for predicting key temperatures, characteristic index, and tar quality in coal pyrolysis. Results from the carbon fractions indicated that the total concentrations of chemical bonds in coal are approximately 150 mmol/g, with more Car−Car and Car−H bonds present in highly mature coal samples, and fewer Cal−Cal, Cal−H, and CO bonds. The breaking behaviors of chemical bonds during coal pyrolysis depend on a combination of temperature and concentration. The breakage of Cal−Cal bond contributes significantly to the pyrolytic weight loss of coal, accompanied by the decrease of Cal−H bonds along with the removal of aliphatic groups. Furthermore, as coal maturity increases, tar from fast pyrolysis contains more polycyclic aromatic hydrocarbons with a higher average molecular weight. The average number of aromatic rings in tar components is notably lower than that of aromatic clusters in coal. These results will contribute to a better understanding of the relationship between coal structure and reactivity, and may provide valuable insights for the efficient and clean utilization of coal.

Sulfotransferase-mediated phase II drug metabolism prediction of substrates and sites using accessibility and reactivity-based algorithms.

Sulphotransferases (SULTs) are a major phase II metabolic enzyme class contributing ~20 % to the Phase II metabolism of FDA-approved drugs. Ignoring the potential for SULT-mediated metabolism leaves a strong potential for drug-drug interactions, often causing late-stage drug discovery failures or black-boxed warnings on FDA labels. The existing models use only accessibility descriptors and machine learning (ML) methods for class and site of sulfonation (SOS) predictions for SULT. In this study, a variety of accessibility, reactivity, and hybrid models and algorithms have been developed to make accurate substrate and SOS predictions. Unlike the literature models, reactivity parameters for the aliphatic or aromatic hydroxyl groups (R/Ar-O-H), the Bond Dissociation Energy (BDE) gave accurate models with a True Positive Rate (TPR)=0.84 for SOS predictions. We offer mechanistic insights to explain these novel findings that are not recognized in the literature. The accessibility parameters like the ratio of Chemgauss4 Score (CGS) and Molecular Weight (MW) CGS/MW and distance from cofactor (Dis) were essential for class predictions and showed TPR=0.72. Substrates consistently had lower BDE, Dis, and CGS/MW than non-substrates. Hybrid models also performed acceptablely for SOS predictions. Using the best models, Algorithms gave an acceptable performance in class prediction: TPR=0.62, False Positive Rate (FPR)=0.24, Balanced accuracy (BA)=0.69, and SOS prediction: TPR=0.98, FPR=0.60, and BA=0.69. A rule-based method was added to improve the predictive performance, which improved the algorithm TPR, FPR, and BA. Validation using an external dataset of drug-like compounds gave class prediction: TPR=0.67, FPR=0.00, and SOS prediction: TPR=0.80 and FPR=0.44 for the best Algorithm. Comparisons with standard ML models also show that our algorithm shows higher predictive performance for classification on external datasets. Overall, these models and algorithms (SOS predictor) give accurate substrate class and site (SOS) predictions for SULT-mediated Phase II metabolism and will be valuable to the drug discovery community in academia and industry. The SOS predictor is freely available for academic/non-profit research via the GitHub link.

Cadmium Iodide as a Catalyst for the Addition of Carbon Dioxide to Oxiranes

The CdI2-catalyzed addition of CO2 to oxiranes is presented. The catalysts are obtained by mixing amines with CdI2. It is found that amines with a large number of aliphatic groups provide the higher conversion; the presence of additional OH and NH groups negatively affects the conversion.