Halogen-Based 17ß-HSD1 Inhibitors: Insights from DFT, Docking, and Molecular Dynamics Simulation Studies.

The high expression of 17ß-hydroxysteroid dehydrogenase type 1 (17ß-HSD1) mRNA has been found in breast cancer tissues and endometriosis. The current research focuses on preparing a range of organic molecules as 17ß-HSD1 inhibitors. Among them, the derivatives of hydroxyphenyl naphthol steroidomimetics are reported as one of the potential groups of inhibitors for treating estrogen-dependent disorders. Looking at the recent trends in drug design, many halogen-based drugs have been approved by the FDA in the last few years. Here, we propose sixteen potential hydroxyphenyl naphthol steroidomimetics-based inhibitors through halogen substitution. Our Frontier Molecular Orbitals (FMO) analysis reveals that the halogen atom significantly lowers the Lowest Unoccupied Molecular Orbital (LUMO) level, and iodine shows an excellent capability to reduce the LUMO in particular. Tri-halogen substitution shows more chemical reactivity via a reduced HOMO-LUMO gap. Furthermore, the computed DFT descriptors highlight the structure-property relationship towards their binding ability to the 17ß-HSD1 protein. We analyze the nature of different noncovalent interactions between these molecules and the 17ß-HSD1 using molecular docking analysis. The halogen-derived molecules showed binding energy ranging from -10.26 to -11.94 kcal/mol. Furthermore, the molecular dynamics (MD) simulations show that the newly proposed compounds provide good stability with 17ß-HSD1. The information obtained from this investigation will advance our knowledge of the 17ß-HSD1 inhibitors and offer clues to developing new 17ß-HSD1 inhibitors for future applications.

Perioperative Anesthesia and Acute Smell Alterations in Spine Surgery: A "Sniffing Impairment" Influencing Refeeding?

Medications for general anesthesia can cause smell alterations after surgery, with inhalation anesthetics being the most acknowledged drugs. However, spine patients have been poorly studied in past investigations and whether these alterations could influence the refeeding remains unclear. This research aims to observe detectable dysosmias after spine surgery, to explore any amplified affection of halogenates (DESflurane and SEVoflurane) against total intravenous anesthesia (TIVA), and to spot potential repercussions on the refeeding. Fifty patients between 50 and 85 years old were recruited before elective spine procedure and tested for odor acuity and discrimination using the Sniffin' Sticks test. The odor abilities were re-assessed within the first 15 h after surgery together with the monitoring of food intakes. The threshold reduced from 4.92 ± 1.61 to 4.81 ± 1.64 (p = 0.237) and the discrimination ability reduced from 10.50 ± 1.83 to 9.52 ± 1.98 (p = 0.0005). Anesthetic-specific analysis showed a significant reduction of both threshold (p = 0.004) and discrimination (p = 0.004) in the SEV group, and a significant reduction of discrimination abilities (p = 0.016) in the DES group. No dysosmias were observed in TIVA patients after surgery. Food intakes were lower in the TIVA group compared to both DES (p = 0.026) and SEV (p = 0.017). The food consumed was not associated with the sniffing impairment but appeared to be inversely associated with the surgical time. These results confirmed the evidence on inhalation anesthetics to cause smell alterations in spine patients. Furthermore, the poor early oral intake after complex procedures suggests that spinal deformity surgery could be a practical challenge to early oral nutrition.

New Halogen-Containing Drugs Approved by FDA in 2021: An Overview on Their Syntheses and Pharmaceutical Use.

This review describes the recent Food and Drug Administration (FDA)-approved drugs (in the year 2021) containing at least one halogen atom (covalently bound). The structures proposed throughout this work are grouped according to their therapeutical use. Their synthesis is presented as well. The number of halogenated molecules that are reaching the market is regularly preserved, and 14 of the 50 molecules approved by the FDA in the last year contain halogens. This underlines the emergent role of halogens and, in particular, of fluorine and chlorine in the preparation of drugs for the treatment of several diseases such as viral infections, several types of cancer, cardiovascular disease, multiple sclerosis, migraine and inflammatory diseases such as vasculitis.

Behavioral and Neuronal Effects of Inhaled Bromine Gas: Oxidative Brain Stem Damage.

The risk of accidental bromine (Br2) exposure to the public has increased due to its enhanced industrial use. Inhaled Br2 damages the lungs and the heart; however, adverse effects on the brain are unknown. In this study, we examined the neurological effects of inhaled Br2 in Sprague Dawley rats. Rats were exposed to Br2 (600 ppm for 45 min) and transferred to room air and cage behavior, and levels of glial fibrillary acidic protein (GFAP) in plasma were examined at various time intervals. Bromine exposure resulted in abnormal cage behavior such as head hitting, biting and aggression, hypervigilance, and hyperactivity. An increase in plasma GFAP and brain 4-hydroxynonenal (4-HNE) content also was observed in the exposed animals. Acute and delayed sympathetic nervous system activation was also evaluated by assessing the expression of catecholamine biosynthesizing enzymes, tryptophan hydroxylase (TrpH1 and TrpH2), and tyrosine hydroxylase (TyrH), along with an assessment of catecholamines and their metabolites. TyrH was found to be increased in a time-dependent manner. TrpH1 and TrpH2 were significantly decreased upon Br2 exposure in the brainstem. The neurotransmitter content evaluation indicated an increase in 5-HT and dopamine at early timepoints after exposure; however, other metabolites were not significantly altered. Taken together, our results predict brain damage and autonomic dysfunction upon Br2 exposure.

Recent Strategies for Carbon-Halogen Bond Formation Using Nickel.

Nickel catalysis has demonstrated the capability of performing a broad range of synthetically challenging transformations over the last decade. Though recent literature has focused on the formation of C-C and C-N bonds, a variety of breakthroughs in the field of C-X bond generation have also been reported. A diverse range of strategies using nickel have been developed, in an effort to expand the scope and synthetic utility of these halogenation methods. This Minireview will cover six emerging strategies in this field including: oxidatively induced C-X reductive elimination, triflate-to-halogen exchange reactions, directed C-H halogenation, non-directed electrophilic C-H halogenation of arenes, enantioselective α-fluorination of carbonyl containing compounds, and 1,2-difunctionalization-halogenation reactions. The final section has been split into two parts: nickel-catalyzed hydrohalogenation and nickel-catalyzed carbohalogenation reactions.

Potential hazards of novel waste-derived sorbents for efficient removal of mercury from coal combustion flue gas.

Novel waste-derived sorbents synthesized through one-step co-pyrolysis of wood and PVC (or brominated flame retarded plastic) were demonstrated as cost-effective sorbents for mercury (Hg) removal in our previous studies. To introduce magnetism and improve porosity, Fe species were further doped into such waste-derived sorbents. The ultimate fate of Hg-laden sorbents after their service is mainly disposed in landfill. Therefore, the stability of Hg/halogens on the spent sorbents is an important topic. In this work, the leachability of Hg/Cl/Br from four waste-derived sorbents was evaluated using toxicity characteristic leaching procedure (TCLP). Three traditional sorbents (Cl-impregnated activated carbon, Br-impregnated activated carbon and commercial activated carbon) were also tested for comparison. Experimental results suggested that the stability of Hg/Cl/Br on four waste-derived sorbents was far higher than that prepared by chemical impregnation. For four waste-derived sorbents, little Hg was leached out whereas certain amounts of Cl/Br escaped into the leachate. Interestingly, Fe-doping effectively improved the stability of Hg/Cl/Br on the waste-derived sorbents. Kinetic analysis revealed that diffusion process and surface chemical reaction were respectively the rate-limiting step for waste-derived sorbents before and after Fe-doping. Water-washing pretreatment could remove loosely-bonded Cl/Br from the waste-derived sorbents, while the Cl/Br essential for Hg removal was retained.

CsZn2 BO3 X2 (X2 =F2 , Cl2 , and FCl): A Series of Beryllium-Free Deep-Ultraviolet Nonlinear-Optical Crystals with Excellent Properties.

Designing deep-ultraviolet (DUV) nonlinear-optical (NLO) crystals is one of the major current research interests, but it faces a great challenge. In order to overcome the problem of crystal growth and the toxicity of BeO raw materials in KBe2 BO3 F2 (KBBF), the only applicable DUV NLO crystal so far, we substitute Be2+ cations with Zn2+ in the KBBF structure and modify the halogen anions, by which three new Zn-containing KBBF-like compounds, CsZn2 BO3 X2 (X2 =F2 , Cl2 , and FCl), have been successfully synthesized. They all exhibit excellent NLO properties, including improved SHG responses (2.8-3.5×KDP) and short UV cut-off edges (<190 nm). In comparison with KBBF, CsZn2 BO3 X2 (X2 =F2 , Cl2 , and FCl) are all chemically benign and have better growth habits, so they are all promising as DUV NLO crystals. Further study on structure-property relationships indicates that the mixing of halogen anions is a feasible strategy to enhance the SHG responses of the KBBF family.

Circulating and tissue biomarkers as predictors of bromine gas inhalation.

The threat from deliberate or accidental exposure to halogen gases is increasing, as is their industrial applications and use as chemical warfare agents. Biomarkers that can identify halogen exposure, diagnose victims of exposure or predict injury severity, and enable appropriate treatment are lacking. We conducted these studies to determine and validate biomarkers of bromine (Br2 ) toxicity and correlate the symptoms and the extent of cardiopulmonary injuries. Unanesthetized rats were exposed to Br2 and monitored noninvasively for clinical scores and pulse oximetry. Animals were euthanized and grouped at various time intervals to assess brominated fatty acid (BFA) content in the plasma, lung, and heart using mass spectrometry. Bronchoalveolar lavage fluid (BALF) protein content was used to assess pulmonary injury. Cardiac troponin I (cTnI) was assessed in the plasma to evaluate cardiac injury. The blood, lung, and cardiac tissue BFA content significantly correlated with the clinical scores, tissue oxygenation, heart rate, and cardiopulmonary injury parameters. Total (free + esterified) bromostearic acid levels correlated with lung injury, as indicated by BALF protein content, and free bromostearic acid levels correlated with plasma cTnI levels. Thus, BFAs and cardiac injury biomarkers can identify Br2 exposure and predict the severity of organ damage.

Halogen-Mediated Partial Oxidation of Polyvinyl Alcohol for Tissue Engineering Purposes.

Partial oxidation of polyvinyl alcohol (PVA) with potassium permanganate turned out to be an efficient method to fabricate smart scaffolds for tissue engineering, endowed with biodegradation and protein delivery capacity. This work considered for the first time the use of halogens (bromine, chlorine and iodine) as less aggressive agents than potassium permanganate to perform controlled PVA oxidation, in order to prevent degradation of polymer molecular size upon chemical modification. Oxidized PVA solutions were chemically characterized (i.e., dinitrophenylhydrazine assay, viscosity measurements, molecular size distribution) before preparing physically cross-linked hydrogels. Scaffolds were assessed for their mechanical properties and cell/tissue biocompatibiliy through cytotoxic extract test on IMR-90 fibroblasts and subcutaneous implantation into BALB/c mice. According to chemical investigations, bromine and iodine allowed for minor alteration of polymer molecular weight. Uniaxial tensile tests demonstrated that oxidized scaffolds had decreased mechanical resistance to deformation, suggesting tunable hydrogel stiffness. Finally, oxidized hydrogels exhibited high biocompatibility both in vitro and in vivo, resulting neither to be cytotoxic nor to elicit severe immunitary host reaction in comparison with atoxic PVA. In conclusion, PVA hydrogels oxidized by halogens were successfully fabricated in the effort of adapting polymer characteristics to specific tissue engineering applications.

A Single Atom Change Facilitates the Membrane Transport of Green Fluorescent Proteins in Mammalian Cells.

Direct delivery of proteins into mammalian cells is a challenging problem in biological and biomedical applications. The most common strategies for the delivery of proteins into the cells include the use of cell-penetrating peptides or supercharged proteins. Herein, we show for the first time that a single atom change, hydrogen to halogen, at one of the tyrosine residues can increase the cellular entry of ∼28 kDa green fluorescent protein (GFP) in mammalian cells. The protein uptake is facilitated by a receptor-mediated endocytosis and the cargo can be released effectively into cytosol by co-treatment with the endosomolytic peptide ppTG21.

Caracterización de los episodios de agitación durante la emergencia de la anestesia general en pediatría / Characterization of agitation episodes during the emergence from general anesthesia in Pediatrics

RESUMEN Introducción: la agitación durante la emergencia de la anestesia general es una complicación frecuente en pediatría que puede causar daños físicos, retrasar el alta y aumentar los costos. Objetivo: caracterizar los episodios anestesia general en el paciente pediátrico. Materiales y métodos: se realizó un estudio descriptivo, prospectivo, longitudinal de 246 pacientes que presentaron anestesia general en el Hospital "Eliseo Noel Caamaño" entre septiembre de 2015 y diciembre de 2018. Se estudiaron las variables: edad, género, ASA, tiempo quirúrgico y tiempo anestésico, tipo de cirugía, método de anestesia, agentes usados para la inducción y el mantenimiento, severidad de los episodios y necesidad de tratamiento. Resultados: la mayoría de los pacientes que presentaron anestesia general tenían entre 2 y 6 años (63,4%), eran masculinos (67,9%), ASA I (78,1%) y fueron operados de excéresis de lesiones de partes blandas (27,6%). El tiempo quirúrgico fue de 31,2 ± 10,4 minutos y el anestésico 43,5±8,8 minutos. El método anestésico más indicado fue la anestesia balanceada (84,2%), como inductor el propofol (86,2%) y para el mantenimiento isoflurano (34,1%) y sevoflurano (26,4%). Predominaron los episodios severos (51,2%) y el 56,9% necesitó intervención farmacológica. Conclusiones: esta anestesia fue más frecuente en los menores de seis años, masculinos, sanos, a los cuales se les realizaron procederes cortos, con anestesia balanceada, se usó propofol para la inducción e isoflurano y sevoflurano para el mantenimiento de la anestesia. Prevalecieron los episodios severos y la mayoría requirió tratamiento farmacológico.

ABSTRACT Introduction: agitation during the emergence from general anesthesia is a frequent complication in Pediatrics that can cause physical damages, delay discharge and increase costs. Objective: to characterize the episodes of general anesthesia in the pediatric patient. Materials and methods: a descriptive, prospective, longitudinal study was carried out with 246 patients who presented general anesthesia in the Hospital "Eliseo Noel Caamaño" from September 2015 to December 2018. The studied variables were age, gender, ASA, surgical time, anesthetic time, kind of surgery, anesthetic method, agents used for the induction and maintenance, episodes severity and treatment necessity. Results: most of patients treated with general anesthesia were aged 2-6 years (63.4 %), male (67.9 %), ASA I (78.1 %), and underwent the removal of soft parts lesions (27.6 %). The average surgical time was 31,2 ± 10,4 minutes and the anesthetics one was 43,5±8,8 minutes. The most used anesthetics method was balanced anesthesia (84.2 %), the most used inductor was propofol (86.2 %) and for the maintenance isoflurane (34,1%) and sevoflurane (26,4%). Severe episodes (51,2%) predominated, and 56.9 % needed pharmacologic intervention. Conclusions: this kind of anesthesia is more frequently used in children aged less than 6 years, male, healthy, who underwent short procedures with balanced anesthesia and the use of propofol for the induction and isoflurane and sevoflurane for maintaining it. Severe episodes predominated, and most of them required pharmacologic treatment.

Compilation and evaluation of gas phase diffusion coefficients of halogenated organic compounds.

Organic halogens are of great environmental and climatic concern. In this work, we have compiled their gas phase diffusivities (pressure-normalized diffusion coefficients) in a variety of bath gases experimentally measured by previous studies. It is found that diffusivities estimated using Fuller's semi-empirical method agree very well with measured values for organic halogens. In addition, we find that at a given temperature and pressure, different molecules exhibit very similar mean free paths in the same bath gas, and then propose a method to estimate mean free paths in different bath gases. For example, the pressure-normalized mean free paths are estimated to be 90, 350, 90, 80, 120 nm atm in air (and N2/O2), He, argon, CO2 and CH4, respectively, with estimated errors of around ±25%. A generic method, which requires less input parameter than Fuller's method, is proposed to calculate gas phase diffusivities. We find that gas phase diffusivities in He (and air as well) calculated using our method show fairly good agreement with those measured experimentally and estimated using Fuller's method. Our method is particularly useful for the estimation of gas phase diffusivities when the trace gas contains atoms whose diffusion volumes are not known.

The Remarkable Effect of Halogen Substitution on the Membrane Transport of Fluorescent Molecules in Living Cells.

Small-molecule-based fluorescent probes have become important tools in biology for sensing and imaging applications. However, the biological applications of many of the fluorescent molecules are hampered by low cellular uptake and high toxicity. In this paper, we show for the first time that the introduction of halogen atoms enhances the cellular uptake of fluorescent molecules and the nature of halogen atoms plays a crucial role in the plasma membrane transport in mammalian cells. The remarkably higher uptake of iodinated compounds compared to that of their chloro or bromo analogues suggests that the strong halogen bonding ability of iodine atoms may play an important role in the membrane transport. This study provides a novel strategy for the transport of fluorescent molecules across the plasma membrane in living cells.

Iron-Catalyzed anti-Selective Carbosilylation of Internal Alkynes.

Reported is the anti-selective carbosilylation of internal alkynes with silylborane and alkyl halides using a FeBr2 /DPPE catalyst system. The iron catalyst allows simultaneous introduction of a carbon electrophile and a silicon nucleophile to simple internal alkynes, including diaryl-, dialkyl-, and aryl/alkyl-substituted alkynes, in a highly stereoselective manner. Alkyl halides are applicable as the electrophiles, thereby enabling the synthesis of a variety of tetrasubstituted alkenylsilanes. In addition, syn-selective carbosilylation was achieved through stereoswitching, by using a silylborane having oxygen functionality on the silyl group. This novel iron-catalyzed carbosilylation is a useful tool for expedient synthesis of stereodefined multisubstituted olefins, a fundamental structural motif in organic chemistry.

Development and application of a sampling method for the determination of reactive halogen species in volcanic gas emissions.

Volcanoes release large amounts of reactive trace gases including sulfur and halogen-containing species into the atmosphere. The knowledge of halogen chemistry in volcanic plumes can deliver information about subsurface processes and is relevant for the understanding of the impact of volcanoes on atmospheric chemistry. In this study, a gas diffusion denuder sampling method using 1,3,5-trimethoxybenzene (1,3,5-TMB)-coated glass tubes for the in situ derivatization of reactive halogen species (RHS) was characterized by a series of laboratory experiments. The coating proved to be applicable to collect selectively gaseous bromine species with oxidation states (OS) of +1 or 0 (such as Br2, BrCl, HOBr, BrO, and BrONO2) while being unreactive to HBr (OS -1). The reaction of 1,3,5-TMB with reactive bromine species forms 1-bromo-2,4,6-TMB-other halogens give corresponding derivatives. Solvent elution of the derivatives followed by analysis with GC-MS results in absolute detection limits of a few nanograms for Br2, Cl2, and I2. In 2015, the technique was applied on volcanic gas plumes at Mt. Etna (Italy) measuring reactive bromine mixing ratios between 0.8 and 7.0 ppbv. Total bromine mixing ratios between 4.7 and 27.5 ppbv were derived from alkaline trap samples, simultaneously taken by a Raschig tube and analyzed with IC and ICP-MS. This leads to the first results of the reactive bromine contribution to total bromine in volcanic emissions, spanning over a range between 12% (±1) and 36% (±2). Our finding is in an agreement with previous model studies, which imply values <44% for plume ages <1 min, which is consistent with the assumed plume age at the sampling sites. Graphical abstract Illustration of the measurement procedure for the determination of reactive halogen species in volcanic plumes.

Olefins from Natural Gas by Oxychlorination.

Ethylene and propylene are the key building blocks of the chemical industry, but current processes are unable to close the growing gap between demand and manufacture. Reported herein is an exceptional europium oxychloride (EuOCl) catalyst for the selective (≥95 %) production of light olefins from ethane and propane by oxychlorination chemistry, thus achieving yields of ethylene (90 %) and propylene (40 %) unparalleled by any existing olefin production technology. Moreover, EuOCl is able to process mixtures of methane, ethane, and propane to produce the olefins, thereby reducing separation costs of the alkanes in natural gas. Finally, the EuOCl catalyst was supported on suitable carriers and evaluated in extrudate form, and preserves performance for >150 h under realistic process conditions.

A Sustainable Redox-Flow Battery with an Aluminum-Based, Deep-Eutectic-Solvent Anolyte.

Nonaqueous redox-flow batteries are an emerging energy storage technology for grid storage systems, but the development of anolytes has lagged far behind that of catholytes due to the major limitations of the redox species, which exhibit relatively low solubility and inadequate redox potentials. Herein, an aluminum-based deep-eutectic-solvent is investigated as an anolyte for redox-flow batteries. The aluminum-based deep-eutectic solvent demonstrated a significantly enhanced concentration of circa 3.2 m in the anolyte and a relatively low redox potential of 2.2 V vs. Li+ /Li. The electrochemical measurements highlight that a reversible volumetric capacity of 145 Ah L-1 and an energy density of 189 Wh L-1 or 165 Wh kg-1 have been achieved when coupled with a I3- /I- catholyte. The prototype cell has also been extended to the use of a Br2 -based catholyte, exhibiting a higher cell voltage with a theoretical energy density of over 200 Wh L-1 . The synergy of highly abundant, dendrite-free, multi-electron-reaction aluminum anodes and environmentally benign deep-eutectic-solvent anolytes reveals great potential towards cost-effective, sustainable redox-flow batteries.

Behavior of Halogen Bonds of the Y-X⋠⋠⋠π Type (X, Y=F, Cl, Br, I) in the Benzene π System, Elucidated by Using a Quantum Theory of Atoms in Molecules Dual-Functional Analysis.

The nature of halogen bonds of the Y-X-✶-π(C6 H6 ) type (X, Y=F, Cl, Br, and I) have been elucidated by using the quantum theory of atoms in molecules (QTAIM) dual-functional analysis (QTAIM-DFA), which we proposed recently. Asterisks (✶) emphasize the presence of bond-critical points (BCPs) in the interactions in question. Total electron energy densities, Hb (rc ), are plotted versus Hb (rc )-Vb (rc )/2 [=(h(2) /8m)∇(2) ρb (rc )] for the interactions in QTAIM-DFA, in which Vb (rc ) are potential energy densities at the BCPs. Data for perturbed structures around fully optimized structures were used for the plots, in addition to those of the fully optimized ones. The plots were analyzed by using the polar (R, θ) coordinate for the data of fully optimized structures with (θp , κp ) for those that contained the perturbed structures; θp corresponds to the tangent line of the plot and κp is the curvature. Whereas (R, θ) corresponds to the static nature, (θp , κp ) represents the dynamic nature of the interactions. All interactions in Y-X-✶-π(C6 H6 ) are classified by pure closed-shell interactions and characterized to have vdW nature, except for Y-I-✶-π(C6 H6 ) (Y=F, Cl, Br) and F-Br-✶-π(C6 H6 ), which have typical hydrogen-bond nature without covalency. I-I-✶-π(C6 H6 ) has a borderline nature between the two. Y-F-✶-π(C6 H6 ) (Y=Br, I) were optimized as bent forms, in which Y-✶-π interactions were detected. The Y-✶-π interactions in the bent forms are predicted to be substantially weaker than those in the linear F-Y-✶-π(C6 H6 ) forms.

A Pronounced Halogen Effect on the Organogelation Properties of Peripherally Halogen Functionalized Poly(benzyl ether) Dendrons.

An interesting halogen-substituent effect on the organogelation properties of poly(benzyl ether) dendrons is reported. A new class of poly(benzyl ether) dendrons with halo substituents decorating their periphery was synthesized and fully characterized. A systematic study on the gelation abilities, thermotropic behaviors, aggregated microstructures, and mechanical properties of self-assembled organogels was performed to elucidate the halogen-substituent effects on their organogelation propensity. It was found that the exact halogen substitutions on the periphery of dendrons exert a profound effect on the organogelation propensity, and dendrons Gn -Cl (n=2, 3) and G2 -I proved to be highly efficient organogelators. The cooperation of multiple π-π, dispersive halogen, CH-π, and weak C-H⋅⋅⋅X hydrogen-bonding interactions were found to be the key contributor to forming the self-assembled gels. Dendritic organogels formed from Gn -Cl (n=2, 3) in 1,2-dichloroethane exhibited thixotropic-responsive properties, and such thixotropic organogels are promising materials for future research and applications.

[Removal of AOX, Chroma and TOC in Chemical Dyestuff Wastewater with Iron Scraps-Fenton-Coagulation Combined Process].

Iron scraps-Fenton-coagulation process was applied to chemical dyestuff wastewater. The removal performance of absorbable organic halogens(AOX), chroma and total organic carbon (TOC) was investigated at different molar ratios of Fe2+ to H2O2 (1:3-1:15), iron scraps reaction time (2-5 h) and Fenton reaction time (20-80 min). The results showed that the removal ratios of AOX, chroma and TOC firstly increased and then decreased with the decrease of the molar ratio of Fe2+ to H2O2, while continuously increased with the increase of iron scraps and Fenton reaction time. The optimal condition was determined as Fe2+:H2O2 ratio of 1:8, iron scraps reaction time of 4 h and Fenton reaction time of 60 min, under which 94.2% of AOX, 93.7% of chroma and 27.2% of TOC were removed. A comparison study revealed that the iron scraps-Fenton-coagulation combined process could achieve much better removal of AOX, chroma and TOC than any other single or combined processes of iron treatment, Fenton oxidation and coagulation. GC-MS analysis revealed that halogenated compounds and anilines were efficiently removed, as well as nitrobenzenes, phenols, benzaldehydes, ethers, nitriles and heterocyclic compounds.·OH was found to devote much in the Fenton reaction according to the tert-butyl alcohol trapping hydroxyl radicals test.