Hydroxyl Substitution Research Articles

Gallic acid enhanced sulfamethoxazole degradation in Cu(II)/peracetic acid system: Key roles of HO• and Cu(III)

The Cu(II)-activated peracetic acid (PAA) process shows promise in eliminating emerging organic contaminants (EOCs), yet it encounters difficulties stemming from the sluggish reduction of Cu(II) to Cu(I). Herein, gallic acid (GA), a representative plant-derived polyphenol, was introduced to enhance the oxidative potential of the Cu(II)/PAA system by facilitating the Cu(II)/Cu(I) redox cycle. The results demonstrated that the GA/Cu(II)/PAA process achieved 90.2 % degradation of sulfamethoxazole (SMX) within 60 minutes under neutral conditions, which is 2.4 times higher than the degradation achieved by the Cu(II)/PAA process alone. Multiple reactive species, including HO•, •CH3, CH3O2•, CH3CO2•, 1O2, and Cu(III), were involved in GA/Cu(II)/PAA system, among which HO• and Cu(III) were identified as the primary contributors to SMX oxidation, while Cu(III) played a dominant role. SMX transformation predominantly occurred through hydroxyl substitution, side chain oxidation, and polymerization pathways, significantly reducing the biotoxicity of the SMX solution post-treatment. Additionally, SMX degradation in GA/Cu(II)/PAA system was significantly enhanced in the presence of high Cl− concentrations, but slightly inhibited by CO32−/HCO3− and humic acid. This study introduces a robust strategy for enhancing the Cu(II)/PAA process and underscores its promising applications, particularly in the remediation of SMX-contaminated wastewater.

Atomically dispersed Fe boosting elimination performance of g-C3N4 towards refractory sulfonic azo compounds via catalyst-contaminant interaction

Herein, an oxygen-doped porous g-C3N4 photocatalyst modified with atomically dispersed Fe (Fe1/OPCN) is successfully prepared and exhibits significant superiority in removing refractory sulfonic azo contaminants from water via catalyst-contaminant interaction. The elimination performance of Fe1/OPCN towards acid red 9, acid red 13 and amaranth containing similar azonaphthalene structure and increasing sulfonic acid groups increases gradually. The amaranth degradation rate of Fe1/OPCN is 17.7 and 6.1 times as that of homogeneous Fenton and OPCN, respectively. In addition, Fe1/OPCN also has more outstanding removal activities towards other contaminants with sulfonic acid and azo groups alone. The considerable enhancement for removing sulfonic azo contaminants of Fe1/OPCN is mainly ascribed to the following aspects: (1) The modified Fe could enhance the adsorption towards sulfonic azo compounds to accelerate the mass transfer, act as e- acceptor to promote interfacial charge separation, and trigger the self-Fenton reaction to convert in-situ generated H2O2 into •OH. (2) Fe(Ⅲ) could coordinate with —N=N— to form d-π conjugation, which could attract e- transfer to attack —N=N— bond. Meanwhile, the inhibited charge recombination could release more free h+ to oxidize sulfonic acid groups into SO4-•. (3) Under the cooperation of abundant multiple active species (•O2-, h+, e-, •OH, SO4-•) formed during the degradation reaction, sulfonic azo compounds could be completely mineralized into harmless small molecules (CO2, H2O, etc.) by means of —N=N— cleavage, hydroxyl substitution, and aromatic ring opening. This work offers a novel approach for effectively eliminating refractory sulfonic azo compounds from wastewater.

Wane-and-wax mechanism of nitrogenous disinfection byproducts with constant Cl/N peak under UV/chlorine treatment: Implication for new drinking water disinfection strategy

Nitrogenous disinfection byproducts (N-DBPs) are notorious for their serious health risks, yet nitrate (NO3-) mediates N-DBPs generation during UV/chlorine treatment remains unexplored. This study investigated the interaction of chlorine and NO3- on N-DBPs formation and developed a specific fragment-based screening method using UPLC-QTOF-MS to explore the underlying mechanism. Results showed that the chlorine-to-nitrogen (Cl/NO3--N) molar ratio significantly affects dichloroacetonitrile (DCAN) and dichloroacetamide (DCAM) generation, with peak concentrations at a Cl/NO3--N molar ratio of around 15. NO3- promotes the production of HO•, which positively correlates with DCAN and DCAM concentrations, also peaking at this ratio. Utilizing our developed method, three key hydroxyl-substituted intermediates that circumvent the previously reported “limiting-steps” in DCAN formation were identified. This reaction proceeds via a stepwise mechanism involving hydroxylation and chlorine substitution to produce hydroxyl-phenylacetonitrile and hydroxyl-chlorine-phenylacetonitrile. The conversion rate of hydroxyl-chlorine-phenylacetonitrile to DCAN was 8.6 times higher at Cl/NO3--N molar ratio of 15 compared to conditions without NO3-, attributed to the weakened bond strength of the side chain, as supported by density functional theory calculations. This study provides novel insights into the mechanistic pathways of DCAN and DCAM formation, critical for developing more effective drinking water disinfection technologies to control N-DBPs.

Ferrate(Ⅵ) oxidative degradation of capecitabine in aquatic matrices: Degradation performance, mechanisms, and toxicity assessment

The growing utilization of anticancer drugs in recent years has resulted in their presence in surface water and sewage, which could have ecological consequences. In this work, ferrate (Fe(VI)) was utilized to oxidize capecitabine (CAP), a frequently used anticancer drug that has gained attention lately. The experiments have demonstrated that Fe(VI) was quite reactive with CAP at pH 7. The addition of humic acid (0.1–10 mg L−1) significantly inhibited the oxidation process. Then, four reaction pathways, mainly including hydroxyl substitution, direct oxidation and cleavage of CO and CN bond were proposed based on twelve products detected by high-resolution hybrid quadrupole time-of-flight mass spectrometer. These pathways were further validated by theoretical calculations. Experiments conducted in water matrices assessed the applicability of Fe(VI) technology. Toxicity assessments of CAP and its intermediates were performed using the TEST program, and predictions indicated that the intermediates were generally less toxic than CAP. Overall, this work revealed that Fe(VI) has great potential to solve the environmental pollution problems associated with capecitabine in water.

Bimetallic metal-organic framework-modified resin for enhanced removal of organophosphorus: Inherent defects and high selectivity

The inherent defects of bimetallic metal–organic frameworks (B-MOFs) play a significant role in enhancing their performance. The combination of resin with MOFs provides a shortcut for optimizing their structure and adsorption performance. This study developed a simple strategy to control the inherent defects of materials by adjusting the Zr/La precursor ratio to enhance the adsorption performance of Zr-La-MOFs@201 for organophosphorus. To achieve this, we prepared a series of X-Zr-La-MOFs@201 and investigated the impact of different ratios on the degree of defects. Among them, 2-Zr-La-MOFs@201 exhibited a maximum adsorption capacity for organophosphorus of 123.6 mg/g, which is 1.25 and 3.08 times compared to UIO-66@201 and D201, respectively. 31P NMR and TGA results indicated that the performance enhancement primarily stemmed from the increased formation of MP bonds, which differs from the commonly mentioned hydroxyl substitution. DFT calculations showed that the presence of defects effectively reduced the reaction activation energy. In actual water treatment, the maximum treatment capacity of this material reached 5000 BV. This impressive performance demonstrates the potential of Zr-La-MOFs@201 for practical applications in other fields, providing a benchmark for the development of new materials.

A low-temperature co-treatment of diethylhexyl phthalate-rich polyvinyl chloride and waste copper catalyst by subcritical water (hydrothermal treatment): Dechlorination, recovery of diethylhexyl phthalate and copper

As one of the most widespread plastics in the world, the recycling of diethylhexyl phthalate-rich polyvinyl chloride (DEHP-rich PVC) faces great challenges because of the high levels of Cl and plasticizers. On the other hand, waste copper catalyst (WCC) discharged from various industrial processes is not effectively recycled. In this study, a significant synergistic effect between the DEHP-rich PVC and WCC was found in a subcritical water (SubCW) medium, and a co-treatment of the DEHP-rich PVC and WCC was developed by the SubCW process. The introduction of WCC significantly improved the dechlorination efficiency of the DEHP-rich PVC to 96.03 % at a low temperature of 250 °C. Under the optimal conditions, the leaching of copper from WCC reached a maximum of 81.08 %. Oil products included DEHP (55.7 %, GC peak area%), 3-methyl-3-heptene (37.3 %, GC peak area%), and 2-ethyl-1-hexanol (7.0 %, GC peak area%). The dechlorination pathways of the DEHP-rich PVC included hydroxyl substitution and direct dechlorination. HCl released from the DEHP-rich PVC led to a decrease in the pH of the system and significant copper leaching from the WCC. DEHP was decomposed by hydrolysis, dehydration, and rearrangement reaction by the SubCW co-treatment process. The enhancement mechanism of the WCC for the dechlorination of the DEHP-rich PVC was based on that the conversion of copper species in the SubCW promoted the formation of hydroxyl radicals and the hydroxyl substitution for chlorine in PVC molecular chain. The proposed SubCW low-temperature co-treatment could be a prospective strategy for the low-energy and synchronous recovery of the two different wastes of the DEHP-rich PVC and WCC.

Multiscale Computational Study of Cellulose Acetate-Water Miscibility: Insights from Molecularly Informed Field-Theoretic Modeling.

Cellulose acetate (CA), a prominent water-soluble derivative of cellulose, is a promising biodegradable ingredient that has applications in films, membranes, fibers, drug delivery, and more. In this work, we present a molecularly informed field-theoretic model for CA to explore its phase behavior in aqueous solutions. By integrating atomistic details into large-scale field-theoretic simulations via the relative entropy coarse-graining framework, our approach enables efficient calculations of CA's miscibility window as a function of the degree of substitution (DS) of cellulose hydroxyl groups with acetate side chains. This allows us to capture the intricate phase behavior of CA, particularly its unique miscibility at intermediate substitution, without relying on experimental input. Additionally, the model directly probes CA solution behavior specific to the relative DS at C2, C3, and C6 alcohol sites, providing insights for the rational design of water-soluble CA for diverse applications. This work demonstrates a promising integration of molecularly informed field theories, complementing wet-lab experimentation, for engineering the next-generation polymeric materials with precisely tailored properties.

Demethylation strategies for spiro-OMeTAD to enhance the thermo-opto-electronic properties as potential hole transport materials in perovskite solar cells

Abstract Spiro-OMeTAD is a widely used hole-transporting material (HTM) that plays a crucial role in achieving highly efficient perovskite solar cells (PSCs). In this work, a series of demethylated functionalized spiro-OMeTAD-based derivatives with different numbers of hydroxyl substituted groups (named as SOH2, SOH4, and SOH6) were synthesized, and their thermal, optical, electrical, and electrochemical properties have been investigated as potential HTMs for PSCs. It has been found that the molecule with six hydroxyl substituted groups on the spiro-OMeTAD-based structure SOH6 exhibited the highest glass transition temperature (T g) and melting point (T m) as compared to SOH2 and SOH4 molecules. The UV–vis absorption spectra portrayed a distinct pattern with the increase in hydroxyl substituted groups as it was slightly blue-shifted for the SOH6 molecule compared to red-shifted for SOH2 and SOH4 molecules. Carrier mobility shows a notable improvement with the hydroxyl substitution. The density functional theory (DFT) has provided useful insight into identifying the chemical stability of spiro-OMeTAD derivatives. In the device simulation, hydroxyl-substituted spiro SOH2 was found to outperform its pristine counterpart, achieving a peak PCE of 17.61% with a V oc of 0.98 V, a J sc of 22.69 mA cm−2, and an FF of 80.67% within the device structure FTO/TiO2/MAPbI3/HTMs/Au. This investigation provided insight into the development of novel spiro-OMeTAD-based derivatives with enhanced optoelectronic properties and showed promising potential for addressing the limitations of traditional HTMs in PSCs.

Degradation of emerging contaminants in synthetic hydrolyzed urine by UV/peracetic acid: Free radical chemistry, and toxicity analysis

The ecological impact of emerging contaminants (ECs) in aquatic environments has raised concerns, particularly with regards to urine as a significant source of such contaminants in wastewater. The current investigation used the UV/Peracetic Acid (UV/PAA) processes, an innovative advanced oxidation technology, to effectively separate two emerging pollutants from urine at its source, namely, ciprofloxacin (CIP) and bisphenol A(BPA). The research findings demonstrate that the presence of the majority of characteristic ions has minimal impact on the degradation of ECs. However, in synthetic hydrolyzed urine, only NH4+ inhibits the degradation of two types of ECs, with a more pronounced effect observed on CIP degradation compared to BPA.The impact of halogen ions, specifically Cl− and I−, on the degradation of CIP in synthetic hydrolyzed urine was a complex phenomenon. When these two halogen ions are present individually, the generation of reactive halogen species (RHS) within the system enhances the degradation of CIP. However, when both types of ions coexist, the formation of diatomic radical species partially inhibits degradation. In terms of BPA degradation, while the production of reactive chlorine species (RCS) to some extent hinders the reaction rate, the generation of reactive iodine species (RIS) promotes the overall process. CIP undergoes fragmentation of the piperazine and quinoline rings, decarboxylation, defluorination reactions, as well as substitution reactions, leading to the formation of products with simplified structures. The degradation of BPA occurs gradually through hydroxyl and halogen substitution as well as isopropyl cleavage. The preliminary toxicity analysis confirmed that the presence of halogen ions in urine resulted in the formation of halogenated products in two types of ECs, albeit with an overall reduction in toxicity. The UV/PAA processes was considered to be an effective and relatively safe approach for the separation of ECs in urine.

Photodegradation of bisphenol A (BPA) in coastal aquaculture waters: Influencing factors, products, and pathways

Bisphenol A (BPA), an endocrine-disrupting contaminant, is ubiquitous in the environment due to its presence in plastics, wastewater, and agricultural runoff. This study investigated the photodegradation behavior of BPA in coastal aquaculture waters near Qingdao, China. Lower salinity promoted BPA photodegradation, while higher salinity has an inhibitory effect, suggesting slower degradation in seawater compared to ultrapure water. Triplet-excited dissolved organic matter (3DOM*) was identified as the primary mediator of BPA degradation, with additional contributions from hydroxyl radicals (•OH), singlet oxygen (1O2), and halogen radicals (HRS). Alepocephalidae aquaculture water exhibited the fastest degradation rate, likely due to its high DOM and nitrate/nitrite (NO3−/NO2−) content, which are sources of 3DOM* and •OH. A positive correlation existed between NO3−/NO2− concentration and the BPA degradation rate. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis identified the primary BPA photodegradation products, formed mainly through oxidative degradation, hydroxyl substitution, nitration, and chlorination pathways. Elucidating these photodegradation mechanisms provides valuable insights into the environmental fate and potential ecological risks of BPA in aquaculture environments. This knowledge can inform strategies for marine environmental protection and the development of sustainable practices.

Characterisation of Basic Sites on Ga2O3, MgO, and ZnO with Preadsorbed Ethanol and Ammonia-IR Study.

The effect of adsorption of ethanol and ammonia on the basicity of Ga2O3, MgO, and ZnO was examined via IR studies of CO2 adsorption. Ethanol reacts with OH groups on Ga2O3, and MgO, forming ethoxyl groups. The substitution of surface hydroxyls by ethoxyls increases the basicity of the neighbouring oxygen. The ethoxyl groups that also form on ZnO do not contain surface OH groups, but the mechanism of their formation is different. On ZnO, ethoxy groups are formed by the reaction of ethanol with surface oxygens. The presence of ethoxyls on ZnO decreases the basicity because some surface oxygens are already engaged in the bonding of ethoxyl groups. The effect of ammonia adsorption on basicity is different for each oxide. For Ga2O3, ammonia adsorption increases the basicity of neighbouring oxygen sites. Ammonia is not adsorbed on MgO; therefore, it does not change the basicity of this oxide. Ammonia adsorbed on ZnO forms coordination bonds with Zn sites; it does not change the number of basic sites but changes how carbonate species are bonded to surface sites.

Maize (Zea mays L.) Plants Alter the Fate and Accumulate Nonextractable Residues of Sulfamethoxazole in Farmland Soil.

The fate of sulfonamide antibiotics in farmlands is crucial for food and ecological safety, yet it remains unclear. We used [phenyl-U-14C]-labeled sulfamethoxazole (14C-SMX) to quantitatively investigate the fate of SMX in a soil-maize system for 60 days, based on a six-pool fate model. Formation of nonextractable residues (NERs) was the predominant fate for SMX in unplanted soil, accompanied by minor mineralization. Notably, maize plants significantly increased SMX dissipation (kinetic constant kd = 0.30 day-1 vs 0.17 day-1), while substantially reducing the NER formation (92% vs 58% of initially applied SMX) and accumulating SMX (40%, mostly bound to roots). Significant NERs (maximal 29-42%) were formed via physicochemical entrapment (determined using silylation), which could partially be released and taken up by maize plants. The NERs consisted of a considerable amount of SMX formed via entrapment (1-8%) and alkali-hydrolyzable covalent bonds (2-12%, possibly amide linkage). Six and 10 transformation products were quantified in soil extracts and NERs, respectively, including products of hydroxyl substitution, deamination, and N-acylation, among which N-lactylated SMX was found for the first time. Our findings reveal the composition and instability of SMX-derived NERs in the soil-plant system and underscore the need to study the long-term impacts of reversible NERs.

Thyroid Hormone Receptor Agonistic and Antagonistic Activity of Newly Synthesized Dihydroxylated Polybrominated Diphenyl Ethers: An In Vitro and In Silico Coactivator Recruitment Study.

Dihydroxylated polybrominated diphenyl ethers (DiOH-PBDEs) could be the metabolites of PBDEs of some organisms or the natural products of certain marine bacteria and algae. OH-PBDEs may demonstrate binding affinity to thyroid hormone receptors (TRs) and can disrupt the functioning of the systems modulated by TRs. However, the thyroid hormone disruption mechanism of diOH-PBDEs remains elusive due to the absence of diOH-PBDEs standards. This investigation explores the potential disruptive effects of OH/diOH-PBDEs on thyroid hormones via competitive binding and coactivator recruitment with TRα and TRβ. At levels of 5000 nM and 25,000 nM, 6-OH-BDE-47 demonstrated significant recruitment of steroid receptor coactivator (SRC), whereas none of the diOH-PBDEs exhibited SRC recruitment within the range of 0.32-25,000 nM. AutoDock CrankPep (ADCP) simulations suggest that the conformation of SRC and TR-ligand complexes, particularly their interaction with Helix 12, rather than binding affinity, plays a pivotal role in ligand agonistic activity. 6,6'-diOH-BDE-47 displayed antagonistic activity towards both TRα and TRβ, while the antagonism of 3,5-diOH-BDE-100 for TRα and TRβ was concentration-dependent. 3,5-diOH-BDE-17 and 3,5-diOH-BDE-51 exhibited no discernible agonistic or antagonistic activities. Molecular docking analysis revealed that the binding energy of 3,3',5-triiodo-L-thyronine (T3) surpassed that of OH/diOH-PBDEs. 3,5-diOH-BDE-100 exhibited the highest binding energy, whereas 6,6'-diOH-BDE-47 displayed the lowest. These findings suggest that the structural determinants influencing the agonistic and antagonistic activities of halogen phenols may be more intricate than previously proposed, involving factors beyond high-brominated PBDEs or hydroxyl group and bromine substitutions. It is likely that the agonistic or antagonistic propensities of OH/diOH-PBDEs are instigated by protein conformational changes rather than considerations of binding energy.

Semisynthesis of new sulfated heterorhamnan derivatives obtained from green seaweed Gayralia brasiliensis and evaluation of their anticoagulant activity

Marine green algae produce sulfated polysaccharides with diverse structures and a wide range of biological activities. This study aimed to enhance the biotechnological potential of sulfated heterorhamnan (Gb1) from Gayralia brasiliensis by chemically modifying it for improved or new biological functions. Using controlled Smith Degradation (GBS) and O-alkylation with 3-chloropropylamine, we synthesized partially water-soluble amine derivatives. GBS modification increase sulfate groups (29.3 to 37.5 %) and α-l-rhamnose units (69.9 to 81.2 mol%), reducing xylose and glucose, compared to Gb1. The backbone featured predominantly 3- and 2-linked α-l-rhamnosyl and 2,3- linked α-l-rhamnosyl units as branching points. Infrared and NMR analyses confirmed the substitution of hydroxyl groups with aminoalkyl groups. The modified compounds, GBS-AHCs and GBS-AHK, exhibited altered anticoagulant properties. GBS-AHCs showed reduced effectiveness in the APTT assay, while GBS-AHK maintained a similar anticoagulant activity level to Gb1 and GBS. Increased nitrogen content and N-alkylation in GBS-AHCs compared to GBS-AHK may explain their structural differences. The chemical modification proposed did not enhance its anticoagulant activity, possibly due to the introduction of amino groups and a positive charge to the polymer. This characteristic presents new opportunities for investigating the potential of these polysaccharides in various biological applications, such as antimicrobial and antitumoral activities.

Efficient removal of Basic Violet 16 by a multistage oxygen enhanced liquid glow discharge plasma system: Mechanism and roles of reactive species quantified by machine learning

A multistage oxygen enhanced Liquid Glow Discharge Plasma reactor (LGDP/multistage oxygen, LGDP/M-O2) was designed to improve the removal efficiency of organic dyes in wastewater. As a result of the multistage oxygen system, the degradation rate constant of Basic Violet 16 (BV16) was enhanced by approximately 18 times, the decolorization rate of BV16 was 97.39 % in 4 min, and the removal rate of TOC was 33.32 % in 10 min. Detailed study of how the system works to help break down pollutants. The reactive species series of experiments showed that multistage oxygen injection strongly promoted reactive species production and utilization. Meanwhile, a machine learning model to quantify the contribution of reactants was proposed. Machine learning indicated the dominating contribution of reactive oxygen species (63.89 %) and reactive chlorine species (21.92 %) in the degradation of BV16. In addition, the transformation intermediates during the degradation of BV16 were monitored. Accordingly, three possible degradation pathways of BV16 in the LGDP/M-O2 system were proposed, i.e., benzene ring substitution of hydroxyl groups, hydroxyl addition of C=C double bond, and halogenation of benzene rings. This study demonstrates the importance of the LGDP/M-O2 system for organic dye removal from wastewater.

Effects of three polyphenols with different numbers of phenolic hydroxyls on the structural and interfacial properties and lipid-protein co-oxidation of oil body emulsions

Oil bodies (OBs) are organelles for storing lipids, and they are composed of lipid cores and monolayer phospholipid protein membranes. During storage, membrane proteins anchored in the lipid core are often damaged by lipid oxidation products, leading to oxidative damage and a decreased quality of emulsified foods. Here, three natural antioxidants (gallic acid (GA), epigallocatechin gallate (EGCG), and tannic acid (TA)) were added to OB emulsions to study the effects of polyphenols on protein interfacial properties during oxidation and the lipid-protein co-oxidation behavior. Compared to GA, EGCG and TA with higher molecular weights and hydroxyl substitution showed better antioxidant activity, metal chelating activity, iron reduction ability, and affinity for OB. The polyphenols significantly reduced the contents of free amino and sulfhydryl groups in OB. Infrared spectroscopy analysis indicate that hydrogen bonding and hydrophobic interactions may exist between the polyphenols and OB. During storage, polyphenols inhibited >23% of the primary and secondary lipid oxidation products in the emulsions, whereas the formation of carbonyl groups and disappearance of sulfhydryl groups were only inhibited by 10.7% and 7.4%, respectively, indicating that polyphenols preferentially inhibited lipid oxidation over protein oxidation. Electrophoresis results showed that moderate oxidation (3 days of storage) disrupted the disulfide bonds of proteins. Note that moderate oxidation enhanced the interfacial properties of OB proteins, whereas excessive oxidation led to protein aggregation. This study offers new perspectives on using polyphenols to regulate the lipid-protein co-oxidation in OB, as well as the different properties of OB proteins after oxidation.

Scutellarein: a review of chemistry and pharmacology.

To get a better understanding of the scientific values of flavone scutellarein (SCT), and to encourage its applications in human health, the current review systematically summarizes the natural observation, biosynthesis, synthesis, pharmacology, pharmacokinetics, and recent synthetic advances. Scientific sources to search for references included Google Scholar, Scopus, Web of Science, PubMed, Sci-Finder, and journal websites. The references have been collected from the 1970s to the present. "Scutellarein" is the most meaningful keyword to search for publications, in which it was used alone or in combination with other keywords. SCT as a hydrophobic flavonoid can be found in various medicinal plants of the families Lamiaceae, Compositae, and Verbenaceae. Flavone SCT has drawn much interest due to its wide pharmacological effects, such as anticancer, anti-inflammation, antioxidant, antiobesity, and vasorelaxant. The SCT treatments also possessed a lot of positive results in the neuron, liver, heart, lung, kidney, bone, and skin protective experiments, and human sperm function enhancement. Its underlying mechanism of action may relate to the apoptotic program and cytokine inhibition by regulating a panel of the signaling pathway, e.g., NF-κB (nuclear factor kappa B)/MAPK (mitogen-activated protein kinase), IκBa (nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitors alpha)/NF-κB, TRAF2 (tumor necrosis factor receptor-associated factor 2)/NF-κB, and PTEN (phosphatase and tension homologue deleted on chromosome 10)/Akt (protein kinase B)/NF-κB. In addition, the metabolic actions and synthetic derivative promotions of SCT were mostly based on the substitution of hydroxyl groups. Collectively, the studies that aim to highlight the role of scutellarein in preclinical and clinical treatments are urgently needed. More and more experiments to improve its bioavailability are expected.

Water Adsorption on π-Surfaces of Open-Fullerenes.

Understanding the water adsorptive behavior of fullerenes is of particular importance for their material application in aqueous media. The conventional fullerenols usually provide complex physical pictures of water adsorption due to their uncontrollable hydroxylation degree and substitution pattern. Herein, we focus on poorly hydroxylated fullerenes with well-defined structures. The water adsorptive behavior was examined by synchrotron IR spectroscopy and computational studies. As a result, three types of IR bands were observed for adsorbed water. The population of the three states was considerably altered by the orientational difference of the hydroxy groups. Nevertheless, water adsorption could not occur for 9-fluorenol and catechol. This indicates that the Lewis acidic fullerene π-surface plays a prominent role in water adsorption, while the rather Lewis basic π-surface of 9-fluorenol is unable to attract much water at a boundary with humid air.

Photochemical Degradation of the New Nicotine Pesticide Acetamiprid in Water.

Acetamiprid is a novel nicotinic pesticide widely used in modern agriculture because of its low toxicity and specific biological target properties. The objective of this study was to understand the photolysis pattern of acetamiprid in the water column and elucidate its degradation products and mechanism. It was observed that acetamiprid exhibited different photolysis rates under different light source conditions in pure water, with ultraviolet > fluorescence > sunlight; furthermore, its photolysis half-life ranged from 17.3 to 28.6h. In addition, alkaline conditions (pH 9.0) accelerated its photolysis rate, which increased with pH. Using gas chromatography-mass spectrometry, five direct photolysis products generated during the exposure of acetamiprid to pure water were successfully separated and identified. The molecular structure of acetamiprid was further analyzed using density functional theory, and the active photodegradation sites of acetamiprid were predicted. The mechanism of the photolytic transformation of acetamiprid in water was mainly related to hydroxyl substitution and oxidation. Based on these findings, a comprehensive transformation pathway for acetamiprid was proposed.

Degradation mechanisms and toxicity determination of bisphenol A by FeOx-activated peroxydisulfate under ultraviolet light

ABSTRACT Ultraviolet light (UV)-assisted advanced oxidation processes (AOPs) are commonly used to degrade organic contaminants. However, this reaction system's extensive comprehension of the degradation mechanisms and toxicity assessment remains inadequate. This study focuses on investigating the degradation mechanisms and pathways of bisphenol A (BPA), generation of reactive oxygen species (ROS), and toxicity of degradation intermediates in UV/PDS/ferrous composites (FeOx) systems. The degradation rate of BPA gradually increased from the initial 11.92% to 100% within 120 min. Sulfate radicals ( SO 4 . − ), hydroxyl radicals (.OH), superoxide anions ( O 2 . − ), and singlet oxygen (1O2) were the primary factors in the photocatalytic degradation of BPA in the UV/PDS/FeOx systems. The main reactions of BPA in this system were deduced to be β-bond cleavage, hydroxyl substitution reaction, hydrogen bond cleavage, and oxidation reaction. A trend of decreasing toxicity for the degradation intermediates of BPA was observed according to the toxicity investigations. The efficient degradation of BPA in UV/PDS/FeOx systems provided theoretical data for AOPs, which will improve the understanding of organic contaminants by FeOx in natural industry wastewater.