Simultaneous Degradation, Dehalogenation, and Detoxification of Halogenated Antibiotics by Carbon Dioxide Radical Anions

Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number of factors.Halogen moieties exhibit strong resistance to oxidative radicals,affecting the dehalogenation and detoxification efficiencies.To address these limitations of AOPs,advanced reduction processes(ARPs)have been proposed.Herein,a novel nucleophilic reductant—namely,the carbon dioxide radical anion(CO_(2)^(·-))—is introduced for the simultaneous degradation,dehalogenation,and detoxification of florfenicol(FF),a typical halogenated antibiotic.The results demonstrate that FF is completely eliminated by CO_(2)^(·-),with approximately 100%of Cland 46%of Freleased after 120 min of treatment.Simultaneous detoxification is observed,which exhibits a linear response to the release of free inorganic halogen ions(R2=0.97,p<0.01).The formation of halogen-free products is the primary reason for the superior detoxification performance of this method,in comparison with conventional hydroxyl-radical-based AOPs.Products identification and density functional theory(DFT)calculations reveal the underlying dehalogenation mechanism,in which the chlorine moiety of FF is more susceptible than other moieties to nucleophilic attack by CO_(2)^(·-).Moreover,CO_(2)^(·-)-based ARPs exhibit superior dehalogenation efficiencies(>75%)in degrading a series of halogenated antibiotics,including chloramphenicol(CAP),thiamphenicol(THA),diclofenac(DLF),triclosan(TCS),and ciprofloxacin(CIP).The system shows high tolerance to the pH of the solution and the presence of natural water constituents,and demonstrates an excellent degradation performance in actual groundwater,indicating the strong application potential of CO_(2)^(·-)-based ARPs in real life.Overall,this study elucidates the feasibility of CO_(2)^(·-)for the simultaneous degradation,dehalogenation,and detoxification of halogenated antibiotics and provides a promising method for their regulation during water or wastewater treatment.

π-Pimer,π-Dimer,π-Trimer,and 1Dπ-Stacks in a Series of Benzene Triimide Radical Anions:Substituent-Modulated π Interactions and Physical Properties in Crystalline State

We herein present the efficient syntheses,crystal structures,and physical properties of a series of novel benzene triimide(BTI)radical anions,emphasizing the relationship between molecular structure with spin–spin intermolecular interactions and physical properties in the crystalline state.BTI radical crystals were preparedby reducingvarious substitutedBTIs(1)with cobaltocene(CoCp2),followed by sequential crystallization processes.Two isolable radical species,that is,neutral molecule-radical anion pair(2)and monoradical species(3),were obtained from BTIs bearing small substituents(ethyl and propyl),while for those bearing larger substituents(butyl,hexyl,and benzyl)sole monoradicals(3)were produced.The radical species showed diverse intermolecular stackings in the crystalline state referred to asπ-pimer,π-dimer,alternatingπ-trimer,and one-dimensional(1D)slippedπ-stacks depending on the length and size of the substituents.Different spin–spin interactions arising from the substituent-tuned radical packings were demonstrated by electron spin resonance(ESR)spectra.The structure–property relationshipwas studied in terms of magnetism and conductivity.The radicalπ-pimers andπ-stacks with effective charge transport exhibited paramagnetic property and conductivity feasibly at room temperature,whileπ-dimers andπ-trimers featuring thermally populated spin-triplet stateswere antiferromagnetic and nonconductive due to their strong radical–radical pairing effect.

ESR STUDIES ON THE SEMIQUINONE RADICAL ANIONS OF HYPOCRELLIN B AND ITS DERIVATIVES AND THE PRODUCTION OF ^(1)O_(2),O_(2)^(█*)

Ⅰ. INTRODUCTIONHypocrellins are 3, 10-dihydroxyl-4, 9-perylenequinone derivatives. They are potent inhibitors of cancer cells. Besides 1O2 and O2, other radicals could also be involved in the effects of Hypocrellins on the photosensitization of erythrocyte membranes. The ESR signal with hyperfine structures could be obtained after illumination of Hypocrellin A, B (HA,

ACTIVE INTERMEDIATES IN PHOTORADICAL AGING OF POLYMERS

The data referring to the mechanism and efficiency of electronically excited macroradical and radical anionreactions, the important role of photochemical chain reactions in polymers are presented, It was found that by varying photonenergy, temperature, photolysis time and competition between thermal and photochemical reactions, it is possible to change the functional composition and molecular weight distribution of polymers.

Superoxide Anion Radical Scavenging Ability of Quaternary Ammonium Salt of Chitosan

A series of N-alkyl or N-aryl chitosan quaternary ammonium salt were prepared using 96% deacetylated chitosan. Their scavenging activities against superoxide anion radical were investigated by chemiluminescence. The IC50 values of these compounds range from 280 to 880 μg/mL, which should be attributed to their different substitutes.

Synthesis of water-soluble cystine C_(60) derivative with catalyst and its active oxygen radical scavenging ability

A novel water-soluble cystine C60 derivative was synthesized in the presence of the catalyst, tetrabutylammonium hydroxide （TBAH）. The product was characterized by FT-IR, UV, ^1H NMR, ^13C NMR, MS and elemental analysis. Furthermore, the scavenging ability to superoxygen anion radical O2^·- and hydroxyl radical ^·OH was studied by chemiluminescence. It was found that cystine C60 derivative showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration （IC50） for superoxygen anion radical and hydroxyl radical were 0.167 and 0.008 mg/mL, respectively.

Study on Inhibition Effects of Rare Earths on Superoxide Anion Radical by Using Pulse Radiolysis

The inhibition effect of rare earths on the production of ·O - 2 produced by radiolysis of aqueous sodium formate saturated with O 2 with high energy pulse electron beam was studied. The result indicates that rare earth nitrate obviously inhibits the production of ·O - 2 . The inhibition rate is between 28 6% and 92%. The inhibition effect increases with the increase of rare earth nitrates concentration. The distinguish dose effect relationship was observed.

Active Oxygen Radical Scavenging Ability of Water-Soluble β-Alanine C_(60) Adducts

Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively. It was found thatβ-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.

Inactivation of Bacillus Subtilis by Atomic Oxygen Radical Anion

UAtomic oxygen radical anion （O-） is one of the most active oxygen species, and has extremely high oxidation ability toward small-molecules of hydrocarbons. However, to our knowledge, little is known about the effects of O- on cells of micro-organisms. This work showed that O- could quickly react with the Bacillus subtilis cells and seriously damage the cell walls a s well as their other contents, leading to a fast and irreversible inactivation. SEM micrographs revealed that the cell structures were dramatically destroyed by their exposure to O-. The inactivation efficiencies of B. subtilis depend on the O- intensity, the initial population of cells and the treatment temperature, but not on the pH in the range of our investigation. For a cell concentration of 10^6 cfu/ml, the number of survived cells dropped from 10^6 cfu/ml to 10^3 cfu/ml after about five-minute irradiation by an O- flux in an intensity of 233 nA/cm^2 under a dry argon environment （30 ℃, 1 atm, exposed size： 1.8 cm^2）. The inactivation mechanism of micro-organisms induced by O- is also discussed.

Persistent radical anion of perylene dianhydride:an emerging metal-free photocatalyst for near-infrared photocontrolled RAFT polymerization

Developing a new type of photocatalyst(PC) and catalytic mechanism for near-infrared(NIR) photocontrolled reversibledeactivation radical polymerization(RDRP) system is charming but challenging.Herein,a novel PC of the persistent radical anion(PRA)(possessing the properties of both radical and anion) was developed for NIR photocontrolled reversible additionfragmentation chain transfer(RAFT) polymerization,enabling successful polymerization while gaining a deep insight into the mechanism of photo-induced electron transfer RAFT(PET-RAFT) polymerization.Different from the conventional and wellaccepted reductive quenching(RQ) pathway,in which the radical anion intermediates of PCs(PCs^(·-)) must be generated in an excited state(ES),here,the PRA(3,4,9,10-perylenetetracarboxylic dianhydride radical anion(PTCDA^(·-))) could generate conveniently in situ in the ground state(GS) and subsequently serve as highly efficient PC in the NIR region(740–850 nm).The successful implementation of this strategy elucidates the peculiar role played by light and the real way of electron transfer behaviors.In fact,the transfer of a single electron from PRA to chain transfer agent(CTA) and cleavage of the C–S bonds is a process from ES to GS,rather than always from GS(PCs^(·-)) to GS(CTA) in the RQ pathway as is well known to all.In addition,the excellent spatial-temporal control and powerful penetration ability of the NIR light were also confirmed by this PRAcatalyzed polymerization system.

Antioxidant Activity of Pigment Extracted from Green-Wheat-Bran

The anthocyanin pigment extracted from green-wheat-bran was studied to identify its antioxidant activity.The antioxidant activities of the pigment were evaluated by anti-lipid peroxidation,total antioxidant activity （TAA）,superoxide anion radical scavenging activity （SARSA）,active oxygen scavenging activity （AOSA）,and DPPH （1,1-diphenyl-2 picrylhydrazyl free radical） radical scavenging activity.The results showed that the pigment had higher antioxidant activity and TAA,SARSA,AOSA and DPPH.scavenging activities at a certain concentration than Vc （antiscorbutic vitamin,vitamin C）,and the capacity increased with the increase of pigment concentration.Its TAA was 51.06 U mL-1,1.73 times of Vc,and SARSA 18 025.21 U mL-1,2.26% higher than Vc,and AOSA 3 776.31 U mL-1,1.24 times of Vc.As to the DPPH.scavenging activity of the pigment,there was a trend that higher concentration performed higher activity significantly improved with the company of Vc.The pigment showed significant antioxidant activities evaluated by different assays.Results will provide a better understanding on antioxidant activity of green wheat and allow the screening or breeding of green wheat varieties with higher antioxidant activity for food processing.

Determination of photochemically-generated reactive oxygen species in natural water

Reactive oxygen species （ROS） can be produced by interactions between sunlight and light-absorbing substances in natural water environment. ROS may participate in the indirect photolysis of trace organic pollutants, therefore resulting in changes in their environmental fates and ecological risks in natural water systems. Bisphenol A （BPA）, an endocrine-disrupting chemical, exits widely in natural waters. The photodegradation of BPA promoted by ROS （-OH, 1O2, HO2./O2^-）, which were produced on the excitation of ubiquitous constituents （such as nitrate ion, humic substances and Fe（Ⅲ）-oxalate complexes） in natural water under simulated solar radiation was investigated. Both molecular probe method and electron spin resonance （ESR） test were used for the characterization of the generated ROS. It was found that .OH was photochemically produced in the presence of nitrate ions, humic substances and Fe（Ⅲ）-oxalate complexes and that 102 was produced with the presence of humic substances. The steady-state concentrations of .OH was 1.27×10^-14 mol/L in a nitrate solution, and the second-order rate constant of BPA with ＂OH was 1.01×10^10 L/（mol.s）.

Synthesis and Antioxidant Properties of Novel Silybin Analogues

Eight novel silybin analogues （7a-h） were synthesized and their antioxidant properties including the capability of scavenging superoxide anion free radicals and the inhibitory effect on DPPH free radicals were determined. Several synthetic compounds showed comparable antioxidative effect to that of quercetin.

SYNTHESIS AND CHARACTERIZATIONS OF NEAR INFRARED ABSORBING POLYMERS

A series of near infrared (NIR) absorbing dinuclear ruthenium dicarbonylhydrazine complexes (DCH-Ru),[{Ru(bpy)_2)_2μ-DCH]^(n+) (where bpy = 2,2'-bipyridinc and n = 2, 3 or 4), were prepared. The DCH-Ru complexes areelectrochromic in the NIR region with a high absorption coefficient at 1550-1600 nm typically over 10000 M^(-1)cm^(-1). DCH-Ru complex polymers with good NIR electrochromic properties were also obtained and processed to make a device foroptical attenuation at a wavelength of 1550 nm. The potential of these DCH-Ru polymers for use in a variable opticalattenuator has been demonstrated with an attenuating power at the 1550-nm telecommunication wavelength over 7.0 dB permicron of polymer film thickness. Other classes of NIR active materials are the pentacenediquinones and the correspondingpoly(ether pentacenediquinone)s. These polymers can be electrochemically reduced to the corresponding semiquinone(radical anion) having NIR absorption within a telecom window (e. g., 1310 nm).

Molecular cloning and functional characterization of a soybean GmG MP1 gene reveals its involvement in ascorbic acid biosynthesis and multiple abiotic stress tolerance in transgenic plants

L-Ascorbic acid （AsA） plays an important role in plants and animals. In plants, GDP-D-mannose pyrophosphorylase （GMP） is essential in the AsA biosynthetic pathway. However, little is known about the genes encoding GMP in soybean and here we report genetic and functional analysis of the GmGMP1 （Glycine max GDP-D-mannose pyrophosphorylase 1） gene in this species. GmGMP1 encoded a GDP-mannose pyrophosphorylase and exhibited higher transcript levels in the leaf than in the root, stem, flower, and seed. Transcript of this gene was ubiquitous in the vegetative and reproductive organs, and was induced by abiotic stress and light. Increasing expression of GmGMP1 in Arabidopsis and soybean through an overexpressing approach caused pronounced enhancement of AsA content, and was implicated in lowering the superoxide anion radical content and lipid peroxidation levels in Arabidopsis, and conferring tolerance to osmotic and high salt stresses during seed germination. The present study represents the first systematic determination of soybean genes encoding GDP-mannose pyrophosphorylase and provides useful evidence for the functional involvement of GmGMP1 in control of AsA content and conferring tolerance to osmotic and salt stress.

Synthesis of α-Bromine-Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br_2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br_2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93. 8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate (MMA) in the presence of copper (I ) halogen and 2, 2' -bipyridine (bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1. 2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by ~1H NMR spectra.

Preparation of Elemental Tellurium Nanoparticles-Sucrose Sol and Its Antioxidant Activity in Vitro

The elemental tellurium nanoparticles （TeNPs） - sucrose sol was prepared by the reaction of sodium tellurite with ascorbic acid in sucrose aqueous solution. The results indicated that TeNPs were dispersion excellent in the TeNPs - sucrose sol and the morphology of TeNPs was needle-like with about 70 nm in width and 500 nm in length. The antioxidant activity of the TeNPs - sucrose sol in vitro was estimated by pyrogallol autoxidation method, Fenton method and oxygen radical absorbance capacity （ORAC） assay. The results showed that a certain amount of TeNPs - sucrose sol could effectively scavenge superoxide anion free radical and hydroxyl free radical with scavenging rates of 73 % and 57 %, respectively. ORAC assay was used to measure the total antioxidant capacity of TeNPs - sucrose sol. The order of ORAC values was 2.25 μmol.L-1 TeNPs - 0.025 % sucrose sol 〉 0.025 % sucrose 〉 2.25 μmol.L-1 Na2TeO3 〉 1.63 μmol.L-1 ascorbic acid. The results suggested that the TeNPs - sucrose sol had the excellent antioxidant activity and TeNPs were the dominating contributors to antioxidant capacity of the TeNPs - sucrose sol.

Electronic Characteristics of Perylene Diimide Anion Radical and Dianion Films by Quantitative Doping

Due to their unique physicochemical properties,the anion radical and dianion of perylene diimide derivatives(PDIs)recently attracted significant attention for organic semiconductors.However,the impact of packing structure and the radical content for carrier transport in the solid state still need to be determined.Bringing the electron-withdrawing groups is an effective strategy for enablingπ−πstacking distance.Here,bay-tetrachloro-substituted PDI(B-4Cl-PDI)anion radical and dianion films were fabricated quantitatively doped with N_(2)H_(4)·H_(2)O.The radical contents were quantitatively calculated by absorption spectra in different doping ratios.The X-ray powder diffraction patterns showed that the anion radical presented a crystalline structure,and dianion aggregates exhibited an amorphous structure.With precise manipulation of the radical content,the anion radical aggregates and dianion aggregates showed the maximum electrical conductivity value of 0.024 and 0.0018 S/cm,respectively.The experiment results show that doping level and aggregate structure play a crucial role in electronic transport properties.

Divergent defluorocarboxylation of α-CF_(3) alkenes with formate via photocatalyzed selective mono-or triple C-F bond cleavage

Unprecedented divergent synthesis of gem-difluorovinylacetic acid and glutaric acid derivatives fromα-CF_(3)alkenes with formate as the carbonyl source was disclosed.The reaction can undergo selective mono-or triple C-F bond cleavage by simply switching the photocatalyst and hydrogen atom transfer(HAT)catalyst under visible-light-induced conditions at room temperature.Foramte acts as both the C1 source and the reductant through the generation of CO_(2)^(·-)species,which underwent Giese radical addition to electron-deficient alkenes to trigger the consecutive C-F bond cleavage and carboxylation process.

The hyperfine structure of electron spin resonance spectrum of tricobalt cluster radical anion CH_3CCo_3(CO)_9^-

CH_3CCo_3(CO)_9 was synthesized from the reaction between chloralose and Co_2(CO)_. The radical anion was generated by electrochemical reduction,and electron spin resonance spectra in THF were recorded by in situ electrolysis in the sample tube in the ESR cavity at 298 and 110K with the spectral data