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Several pyridothiadiazaphosphepinones (3–9) were synthasized by combining tetraphosphorus decasulfide, Lawesson's reagent, phosphorus tribromide, and P,P-dichlorophenyl phosphine with 2-(aminosulfanyl)-6-(3,4-dichlorophenyl)-4-(furan-2-yl)-5-oxo-5,6-dihydropyridine-3-carbonitrile (2). The reaction mechanisms for these products were discussed. On the basis of elemental analysis and spectrum data, the structures of the newly synthesized compounds were determined. The biological activity of every synthesized compound was examined against various microorganisms using the disc diffusion method. The bulk of the microorganisms tested are effectively inhibited by the newly synthesized chemicals.

Introduction: Organophosphorus poisoning is an important medical emergency and its pattern and outcome varies from place to place. Given the widespread availability and use of these chemicals, OP poisoning is quite common following either accidental or intentional exposures. Aims and Objective: This study was conducted to evaluate the spectrum of acute poisoning in a tertiary care hospital. Materials and Methods: This is a retrospective study of organophosphorus poisoning cases brought to emergency department/casualty of a tertiary care hospital from Jan 2011 to Dec 2014. Result: Total 805 cases of acute poisoning were recorded over a period of 4 years. Acute poisoning was common in men, and age group of 20-40 years was the most affected. The most common offending population was poor class (V) and financial burden was the most common reason noted. Conclusion: From these results we found that Organo Phosphorous compounds are commonly ingested with suicidal intent due to its easy availability by young population in rural areas, more commonly males with economical burdens. [ABSTRACT FROM AUTHOR]

Pralidoxime is the only oxime antidote to organophosphate poisoning stocked in the United Kingdom, produced by rational drug design in the 1950s. Typically, it is used alongside atropine, to reverse the effects of acetylcholinesterase inhibition. However, its efficacy has been questioned by recent meta-analyses of use treating attempted suicides in less economically developed countries, where organophosphate poisoning is more common. This policy analysis assesses the likely efficacy of pralidoxime in the United Kingdom, in scenarios largely different from those evaluated in meta-analyses. In all scenarios, the UK delay in antidote administration poses a major problem, as pralidoxime acts in a time-critical reactivation mechanism before "ageing" of acetylcholinesterase occurs. Additionally, changes in the organophosphates used today versus those pralidoxime was rationally designed to reverse, have reduced efficacy since the 1950s. Finally, the current dosage regimen may be insufficient. Therefore, one must re-evaluate our preparedness and approach to organophosphate poisoning in the United Kingdom.

[Display omitted] • DPHOC has been designed and synthesised for the detection of nerve agent simulants. • DPHOC exhibits excellent selectivity and sensitivity toward DMCP in MeOH. • The LOD was determined to be 2.1 µM with a linear range of 5–50 µM. • π-lonepair, π-cation interactions between DPHOC & DMCP plays a key role in sensing. Despite the largely tranquil environment in which humans live, a chemical terrorism attack is still a public safety problem, for which the capacity to quickly and accurately detect chemical warfare agents (CWAs) constitute a significant barrier. In this study, a straightforward fluorescent probe based on dinitrophenylhydrazine has been synthesised. It exhibits great selectivity and sensitivity for the nerve agent mimicking dimethyl chlorophosphate (DMCP) in the MeOH solution. Dinitrophenylhydrazine-oxacalix[4]arene (DPHOC), a 2,4-dinitrophenylhydrazine (2,4-DNPH) derivative, was synthesised and characterized with NMR and ESI-MS. Photophysical behavior, specially spectrofluorometric analysis was introduced to investigate the sensing phenomena of DPHOC toward dimethyl chlorophosphate (DMCP). The LOD of DPHOC toward DMCP was determined to be 2.1 µM, with a linear range from 5 to 50 µM (R2 = 0.99933). Moreover, DPHOC has been proven to be a promising probe toward the real time detection of DMCP. [ABSTRACT FROM AUTHOR]

The present work introduces both synthesis of silica nanoparticles doped with CoII ions by means of differently modified microemulsion water-in-oil (w/o) and Stöber techniques and characterization of the hybrid nanoparticles (CoII@SiO2) by TEM, DLS, XRD, ICP-EOS, SAXS, UV-Vis, and UV-Vis/DR spectroscopy and electrochemical methods. The results reveal the lack of nanocrystalline dopants inside the hybrid nanoparticles, as well as no ligands, when CoII ions are added to the synthetic mixtures as CoII(bpy)3 complexes, thus pointing to coordination of CoII ions with Si-O- groups as main driving force of the doping. The UV-Vis/DR spectra of CoII@SiO2 in the range of d-d transitions indicate that Stöber synthesis in greater extent than the w/o one stabilizes tetrahedral CoII ions versus the octahedral ions. Both cobalt content and homogeneity of the CoII distribution within CoII@SiO2 are greatly influenced by the synthetic technique. The electrochemical behavior of CoII@SiO2 is manifested by one oxidation and two reduction steps, which provide the basis for electrochemical response on glyphosate and HP(O)(OEt)2 with the LOD = 0.1 μM and the linearity within 0.1–80 μM. The Stöber CoII@SiO2 are able to discriminate glyphosate from HP(O)(OEt)2, while the w/o nanoparticles are more efficient but nonselective sensors on the toxicants.

A new wireless and passive surface acoustic wave (SAW)-based chemical sensor for organophosphorous compound (OC) detection is presented. A 434 MHz reflective delay line configuration composed by single phase unidirectional transducers (SPUDTs) and three shorted reflectors was fabricated on YZ LiNbO3 piezoelectric substrate as the sensor element. A thin fluoroalcoholpolysiloxane (SXFA) film acted as the sensitive interface deposited onto the SAW propagation path between the second and last reflectors of the SAW device. The first reflector was used for the temperature compensation utilizing the difference method. The adsorption between the SXFA and OC molecules modulates the SAW propagation, especially for the time delay of the SAW, hence, the phase shifts of the reflection peaks from the corresponding reflectors can be used to characterize the target OC. Prior to the sensor fabrication, the coupling of modes (COM) and perturbation theory were utilized to predict the SAW device performance and the gas adsorption. Referring to a frequency-modulated continuous wave (FMCW)-based reader unit, the developed SAW chemical sensor was wirelessly characterized in gas exposure experiments for dimethylmethylphosphonate (DMMP) detection. Sensor performance parameters such as phase sensitivity, repeatability, linearity, and temperature compensation were evaluated experimentally.

Background: Organophosphorus (OP) poisoning is a major public health problem in developing world. OP pesticides inhibit carboxylic esterase enzymes including plasma cholinesterase (PChE). Clinical manifestations following OP poisoning can be associated with the extent of decrease of PChE. This study was designed to investigate the relevance of PChE level to clinical manifestations in OP poisoning and to evaluate usefulness of PChE in predicting clinical outcomes. Methods: This was a cross-sectional study which was conducted at Jawaharlal Nehru Medical College, Karnataka from 1st October 2009 to 30th September 2010. Seventy-six OP poisoned patients were enrolled and their clinical manifestations were recorded. 5-ml samples of intravenous blood were collected from each patient (on first day and fifth day of treatment) under strict aseptic precaution and the PChE level was measured. Results: In total, mean age of patients were 25.5 (range: 21-30) years. Majority of patients were males (65.7 %), from rural areas (86.84 %) and agricultural workers (25%). Main clinical findings at the time of admission were congested conjunctiva (87%), pin point pupil (83%), lacrimation (80%), vomiting (78%), non-reactive pupil (75%), respiratory distress (60%) and abdominal pain (37%). Mean (SD) PChE at 6 hours post-exposure was 3672.4 (4200.1) IU/L. At presentation, cyanosis, muscle weakness, convulsion, respiratory distress and fasciculation were related to cases with >75%reduction of PChE, while, constricted and non-reactive pupil, lacrimation and congested conjunctivae were related to cases with 50-75% reduction and abdominal pain, dryness of conjunctiva, vomiting and diarrhea were related to

Chemical warfare agents including nerve agents, e.g., sarin, are part of the organophosphorous compounds group known for their extreme lethal potency towards humans. With increasing risks of exposure to these molecules, there is a need for sensitive and selective detection. Infrared absorption spectroscopy is a powerful technique for the identification of molecules by probing their vibro-rotational molecular resonances. However, infrared light wavelength and molecule absorption cross-section dimensions mismatch, significantly hampering light-matter interaction especially at low concentrations, therefore lowering the sensitivity. To overcome this challenge, we propose a rapid chemistry-free III–V semiconductors InAsSb plasmonic sensor working in the mid-infrared with ribbon-shape nano-antennas associated to a confined enhanced electric field at the nanoscale. Exploiting well-known Salisbury perfect absorber structure coupled to an epsilon-near-zero layer benefit both spectral and spatial overlap, two required conditions for surface-enhanced infrared spectroscopy. Finite difference time domain and rigorous coupled-wave analysis coupled to Drude formalism were performed to design the sensor. The plasmonic sensor was exposed to hundreds of ppm-level concentration vapors of dimethyl methylphosphonate, known as DMMP, a commonly used sarin simulant. We determined that DMMP bound to the sensor native oxide to form a 5 Å estimated monolayer. The sensor response results from the coupling between surface plasmons and DMMP molecular vibrations upon adsorption at resonances frequency. Further simulations confirmed experimental results. This work demonstrates the application of III–V semiconductor plasmonics for gas sensing of complex molecules exploiting surface-enhanced infrared absorption. [Display omitted] • Applicability of III–V semiconductor plasmonics for sensing applications. • Use of epsilon-near-zero material to improve light-matter interaction. • Chemistry-free gas phase detection of an organophosphorous sarin simulant. • Sensing of a 5 Å monolayer by surface-enhanced infrared absorption spectroscopy. • Electromagnetic simulations support findings. [ABSTRACT FROM AUTHOR]

[Display omitted] Several pyridothiadiazaphosphepinones (3 – 9) were synthasized by combining tetraphosphorus decasulfide, Lawesson's reagent, phosphorus tribromide, and P,P -dichlorophenyl phosphine with 2-(aminosulfanyl)-6-(3,4-dichlorophenyl)-4-(furan-2-yl)-5-oxo-5,6-dihydropyridine-3-carbonitrile (2). The reaction mechanisms for these products were discussed. On the basis of elemental analysis and spectrum data, the structures of the newly synthesized compounds were determined. The biological activity of every synthesized compound was examined against various microorganisms using the disc diffusion method. The bulk of the microorganisms tested are effectively inhibited by the newly synthesized chemicals. [ABSTRACT FROM AUTHOR]

Objective: to assess the pathological significance of a lipid peroxidation (LPO) process after severe intoxications caused by organophosphorous compounds, alcohol, dichloroethane, the efficiency of its correction with the antioxidants pyrimi-dine and benzimidazole derivatives.Materials and methods. The study was conducted on male rats weighing 160—230 g. Models of intoxications with ethanol, dichloroethane, carbofos, armine, or sodium nitrite in the doses causing 30—50% death were employed. LPO products were studied in the lipid extracts of the brain, myocardium, and liver by various methods. The activity of a number of enzymes (catalase, glucose-6-phosphate dehydrogenase, superoxide dismutase, glutathione peroxidase, Na+, K+-ATPase) was evaluated in the rats. Serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, and acid phosphotase were spectrophotometrically assayed. Quantitative histochemistry was used to determine the activity of succinate dehydrogenase, NAD-diaphorase, and Na+, K+-ATPase. The number of chemical reactions was measured and estimated on a MT-9 TV analyzer microscope. Experimental findings were analyzed by different variation statistical methods using Student’s test.Results. The paper reports the results of comprehensive experimental studies of the efficiency of correction of prooxidative-antioxidative imbalance after severe acute intoxication with chemical prooxidants and some lipophilic xenobiotics. Antioxidants, anti-hypoxants, and actoprotectors, the derivatives of pyrimidine and benzimidazole, were tested.Conclusion. The findings suggest that the immediate sequels of prooxidative-antioxidative imbalance due to experimental intoxications with ethanol, dichloroethane, and organophosphorous compounds are impaired activities of LPO processes, oxidative stress, altered metabolic, bioenergetic processes in organs and tissues. The use hydroxymethyluracil, bemitil, or thietazole largely limits or prevents the above disorders.

2,2-Bis(3,4-dihydro-3-phenyl-2 H-1,3-benzoxazine)propane ( BA-a) is blended with various commercial polyhedral oligomeric silsesquioxane ( POSS) reagents and an organophosphorous compound, bis(4-hydroxyphenyl)phenylphosphine oxide ( BPPO), at a range of loadings (1-10 wt%). The influence of the additives on the onset and rate of polymerisation of BA-a is examined using differential scanning calorimetry. An initial screen of blends containing various additives (5 wt%) shows that a combination of aminoethylaminopropyl isobutyl POSS ( AEAP) and BPPO has the greatest effect on reactivity with a reduction in reaction onset of some 65 K and an increase in glass transition temperature of 18 K when compared with the BA-a homopolymer. The activation energy for the polymerisation of BA-a containing 5 wt% AEAP is determined to be 84-88 kJ mol−1 (using Kissinger and Ozawa kinetic models), with a first-order rate constant of 1.9 × 108 s−1. The thermal stability of the cured blends containing 5 wt% flame retardant is examined using thermogravimetric analysis, and both onset of degradation and char yield are increased by 15 K and 5%, respectively, when compared with the BA-a homopolymer. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The presence of AMPA in environment becomes today a real problem due to its persistence, its toxicity, and its multiple origins (main metabolite of glyphosate, the pesticide the most used in the world; degradation product of personal care and industrial products). This paper reports the development of a simple, effective, cheap and easy electrochemical treatment, for mineralising AMPA under very soft conditions: at room temperature, at free pH, and in a classical open electrochemical cell. The electrode material used is an electrodeposited thin film of birnessite, a non-toxic material, synthesised in very soft conditions. The original idea is to couple the spontaneous oxidative properties of birnessite to an electrochemical oxidation treatment in the aim to increase its reactivity towards this pollutant. Very good mineralisation rates and capacity (≈ 0.115 g AMPA mineralized by gramme of birnessite) were obtained with very low energy supplies (Q ≈ 3 C). Some tests performed with concentrated glyphosate solutions, one of its main parents, give also good results allowing us to envisage the development of an easy method of wastewater treatments at very low costs in complement of classical methods and/or directly at the source of pollution. [ABSTRACT FROM AUTHOR]

A method for quantitative determination of 13 organophosphorous compounds (OPs) was developed and applied to influent, primary sludge, activated sludge, biosolids, primary effluent and final effluent from a wastewater treatment plant (WWTP). The method involved solvent extraction followed by solid phase clean-up and analysis by high performance liquid chromatography positive electrospray ionization-tandem mass spectrometry (HPLC(+ESI)MS/MS). Replicate spike/recovery experiments revealed the method to have good accuracy (70–132%) and precision (<19% RSD) in all matrices. Detection limits of 0.1–5 ng/L for aqueous samples and 0.01–0.5 ng/g for solid samples were achieved. In the liquid waste stream ∑OP concentrations were highest in influent (5764 ng/L) followed by primary effluent (4642 ng/L), and final effluent (2328 ng/L). In the solid waste stream, the highest ∑OP concentrations were observed in biosolids (3167 ng/g dw), followed by waste activated sludge (2294 ng/g dw), and primary sludge (2128 ng/g dw). These concentrations are nearly 30-fold higher than ∑polybrominated diphenyl ether (BDE) concentrations in influents and nearly 200-fold higher than ∑BDE concentrations in effluents from other sites in Canada. Tetrekis(2-chlorethyl)dichloroisopentyldiphosphate (V6), tripropylphosphate (TnPrP), and Tris(2,3-dibromopropyl)phosphate (TDBPP) are investigated for the first time in a WWTP. While TnPrP and TDBB were not detected, V6 was observed at concentrations up to 7.9 ng/g in solid waste streams and up to 40.7 ng/L in liquid waste streams. The lack of removal of OPs during wastewater treatment is a concern due to their release into the aquatic environment. [ABSTRACT FROM AUTHOR]

Vinylized iron oxide magnetic nanoparticles (VMNPs) were incorporated into polymethacrylate monolithic columns to develop novel stationary phases with enhanced separation performance. The VMNPs were dispersed in a polymerization mixture containing gycidyl methacrylate and ethylene glycol dimethacrylate as monomers, cyclohexanol and 1-dodecanol as porogens and azobisisobutyronitrile as initiator. The stability of the VMNPs in the polymerization mixture was investigated at several VMNP contents. Using short UV-polymerization times, polymeric beds with homogenously dispersed VMNPs were obtained. The novel stationary phases were characterized by scanning electron microscopy. The chromatographic performance of these hybrid monoliths was evaluated using alkyl benzenes and organophosphorous pesticides as test solutes. Using capillary electrochromatography, efficiencies up to 130,000 plates/m were achieved. The increase of the specific surface area of hybrid monoliths led to an increase in the retention of all the test analytes, and an enhancement of efficiency. The resulting hybrid monolithic columns exhibited satisfactory column to-column and batch-to-batch reproducibilities with RSDs values below 6%. [ABSTRACT FROM AUTHOR]

Morbidity and mortality due to poisoning is a world wide problem. The pattern poisoning varies from Country to country, place to place and changes over a period of time due to various reasons. The present study is a prospective study conducted at Khaja Banda Nawaz institute of medical science of Gulbarga, (North-Karnataka) during 2011-2013. Total 229 poisoning cases were studied from OPD to IPD, followed from admission to recovery or death in a systematic manner. All these cases were analyzed with an objective of knowing age & sex distribution of victims, commonest type of poison, the manner of poisoning, occupation, and also the rural & urban trends. Among 229 cases, male (51.15%) predominated females (42.85%) with majority (42.25%) belonging to 21-30 yrs age group. The commonest poison encountered was the Organophosphorous compounds (73.14%). Suicide (77.33%) was the commonest manner than accidental poisoning. Agricultural farmers with rural background, belonging to lower socioeconomic strata were the commonest victims (78.29%) compared to others. [ABSTRACT FROM AUTHOR]

Thermolytic decomposition of 3,3'-(ethan-1,2-diyl)bis(1-methyl-1 H-imidazolium) bis-(hexafluorophosphate) ( 1) under reduced pressure results in a 1: 1 mixture of pentafluo-ro(1-ethenyl-3-methyl-2,3-dihydro-1 H-imidazole-2-ylidene-κ C)phosphorous ( 2) and penta- fluoro(3-methyl-1 H-imidazole-κ N)phosphorous ( 3) in an almost quantitate yield. Products 2 and 3 were isolated as individual compounds by fractional recrystallization from hot methanol. Direct observation of a 1: 1 co-crystallite of 2-pentafluorophosphanyl-1-ethenyl-3-methyl-1 H-imidazolium hexafluorophosphate and adduct 2 (compound 5) as a minor coproduct of this reaction reveals a complicated path of the thermolysis. Crystal and molecular structures of compounds 2, 3, and 5 were established by X-ray diffraction analysis. Compound 2 presents the first example of an N-alkenyl substituted Arduengo carbene adduct with a main Group element Lewis acid. Compound 3 presents the second known organic base N-adduct with PF. [ABSTRACT FROM AUTHOR]

The main factors affecting the accuracy and computational cost of the calculation of 31P NMR chemical shifts in the representative series of organophosphorous compounds are examined at the density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2) levels. At the DFT level, the best functionals for the calculation of 31P NMR chemical shifts are those of Keal and Tozer, KT2 and KT3. Both at the DFT and MP2 levels, the most reliable basis sets are those of Jensen, pcS-2 or larger, and those of Pople, 6-311G(d,p) or larger. The reliable basis sets of Dunning's family are those of at least penta-zeta quality that precludes their practical consideration. An encouraging finding is that basically, the locally dense basis set approach resulting in a dramatic decrease in computational cost is justified in the calculation of 31P NMR chemical shifts within the 1-2-ppm error. Relativistic corrections to 31P NMR absolute shielding constants are of major importance reaching about 20-30 ppm (ca 7%) improving (not worsening!) the agreement of calculation with experiment. Further better agreement with the experiment by 1-2 ppm can be obtained by taking into account solvent effects within the integral equation formalism polarizable continuum model solvation scheme. We recommend the GIAO-DFT-KT2/pcS-3//pcS-2 scheme with relativistic corrections and solvent effects taken into account as the most versatile computational scheme for the calculation of 31P NMR chemical shifts characterized by a mean absolute error of ca 9 ppm in the range of 550 ppm. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Dibutyl phosphite, an organophosphorous compound, finds applications in different chemical industries and processes. Here, we report an efficient approach of biodegradation to be eventually used in bioremediation of dibutyl phosphite. Aerobic granules capable of dibutyl phosphite biodegradation were cultivated in a sequencing batch reactor (SBR). The SBR was operated with a 24-h cycle by feeding with dibutyl phosphite as a cosubstrate along with acetate. During the course of the SBR operation, aerobic granules of 0.9 ± 0.3 mm size were developed. Complete biodegradation of 1.4, 2 and 3 mM of dibutyl phosphite was achieved in 4, 5 and 8 h, respectively, accompanied by stoichiometric release of phosphite (H3PO3). Phosphatase activity in the dibutyl phosphite-degrading granular biomass was 3- and 1.5-fold higher as compared to the activated sludge (seed biomass) and acetate-fed aerobic granules, respectively, indicating involvement in the hydrolysis of dibutyl phosphite. Microbial community analysis by t-RFLP showed the presence of 12 different bacterial types. Two bacterial strains capable of growth on dibutyl phosphite as sole carbon source were isolated and characterized as Acidovorax sp. and Sphingobium sp. The results show that aerobic microbial granules based process is suitable for the treatment of dibutyl phosphite contaminated water. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, cultivation of aerobic granular biomass capable of biodegradation of dibutyl phosphite, an organophosphite, and isolation of dibutyl phosphite degrading bacterial strains, are reported for the first time. The strain AMGD5, identified as Sphingobium sp., based on 16S rRNA sequencing, degraded dibutyl phosphite efficiently and utilised it as the sole source of carbon and phosphorus. Microbial degradation of dibutyl phosphite caused a significant decrease in medium pH, leading to cessation of growth and further degradation of dibutyl phosphite. Under buffered conditions, complete degradation of up to 3 mM of dibutyl phosphite was achieved within 60 h. The strain showed almost similar growth pattern when either phosphite or dibutyl phosphite was used as the phosphorous source. A 4-fold enhancement in phosphatase activity was evident in dibutyl phosphite fed cells, implying their role in dibutyl phosphite degradation. Sphingobium sp. AMGD5 can be a potential candidate for bioremediation of dibutyl phosphite contaminated waters or sites. [Copyright &y& Elsevier]

Organophosphorous compounds (OP) have largely been used as pesticides globally. These chemicals induce oxidative stress as a possible mechanism of action, which has been a focus of toxicological research for the last decade. This review evaluated the presence of oxidative stress, balance between total antioxidant capacity, and oxygen free radicals associated with OP compound exposure. Oxidative stress induced by OP leads to disturbances in function of different organs and tissues. Evidence indicates that stimulation of free radical production, induction of lipid peroxidation, and disturbance of the total antioxidant capacity are mechanisms of toxicity induced by most OP. Thus, use of antioxidants may be beneficial in treatment of OP poisoning, which remains to be elucidated with further clinical trials. [ABSTRACT FROM AUTHOR]

The tetracoordinated organophosphorous compound (4 - Chlorophenyl 4 - methyl phenyl Chlorophosphate, 1) were synthesized, characterized and nucleophilic substitution reaction (pyridinolysis) were investigated in acetonitrile at 5.0 o C by varying substituents in nucleophiles. The reactivity is expressed in terms of second-order rate constant, k 2 and measured conductometrically. Physical organic chemistry tools mainly Hammett (ρ), Brönsted (β) Linear Free Energy Relationship (LFER) coefficients being determined in quest for the mechanistic information by comparing pyridinolysis of structurally similar organophosphorous compounds reported earlier. Nice linear correlation being found for Hammett (logk 2 vs σx) and Brönsted (logk 2 vs pK a(x) ) plots. In the light of the reported results the LFER obtained for 1 with negative value of the ρ X , −5.78 and large positive value for β X , 1.17 can be interpreted as S N 2 process, with greater extent of bond formation in TS of 1. [ABSTRACT FROM AUTHOR]

Highlights: [•] Organophosphorous compound membrane transfer was found to be a first-order process. [•] The transfer depended on the toxicants’ partition coefficient and the membrane type. [•] Synthetic membranes may represent a model for the skin without the stratum corneum. [•] Adsorptive powders inhibited the organophosphorous compound membrane transfer. [Copyright &y& Elsevier]

Organophosphorous (OP) Nerve agents (NAs) are known as the deadliest chemical warfare agents. They are divided into two classes of G and V agents. Most of them are liquid at room temperature. NAs chemical structures and mechanisms of actions are similar to OP pesticides, but their toxicities are higher than these compounds. The main mechanism of action is irreversible inhibition of Acetyl Choline Esterase (AChE) resulting in accumulation of toxic levels of acetylcholine (ACh) at the synaptic junctions and thus induces muscarinic and nicotinic receptors stimulation. However, other mechanisms have recently been described. Central nervous system (CNS) depression particularly on respiratory and vasomotor centers may induce respiratory failure and cardiac arrest. Intermediate syndrome after NAs exposure is less common than OP pesticides poisoning. There are four approaches to detect exposure to NAs in biological samples: (I) AChE activity measurement, (II) Determination of hydrolysis products in plasma and urine, (III) Fluoride reactivation of phosphylated binding sites and (IV) Mass spectrometric determination of cholinesterase adducts. The clinical manifestations are similar to OP pesticides poisoning, but with more severity and fatalities. The management should be started as soon as possible. The victims should immediately be removed from the field and treatment is commenced with auto-injector antidotes (atropine and oximes) such as MARK I kit. A 0.5% hypochlorite solution as well as novel products like M291 Resin kit, G117H and Phosphotriesterase isolated from soil bacterias, are now available for decontamination of NAs. Atropine and oximes are the well known antidotes that should be infused as clinically indicated. However, some new adjuvant and additional treatment such as magnesium sulfate, sodium bicarbonate, gacyclidine, benactyzine, tezampanel, hemoperfusion, antioxidants and bioscavengers have recently been used for OP NAs poisoning. [ABSTRACT FROM AUTHOR]

Background. Respiratory failure in acute organophosphate (OP) poisoning can occur early and also relatively late in the clinical course, and the pathophysiology of respiratory failure at these different phases may have important clinical implications. Objective. To compare the electrophysiological findings in patients with early and late respiratory failure following acute OP poisoning. Methods. A prospective observational case series of consenting symptomatic patients with acute OP poisoning were assessed with daily physical examinations and repetitive nerve stimulation (RNS) studies. RNS was done on right and left median and ulnar nerves at 1, 3, 10, 15, 20, and 30 Hz. Outcomes such as need for ventilation and development of intermediate syndrome (IMS) were noted. Early respiratory failure was defined as occurring within 24 hours of ingestion. Results. Seventy-eight patients were recruited for the clinical and electrophysiological study and of those 59 (75.6%) patients had ingested chlorpyrifos. Seven patients developed respiratory failure within 24 hours of ingestion with overt muscarinic signs. They had no electrophysiological abnormalities at median and ulnar nerves before intubation. Three of them later developed 'forme fruste' IMS. Five other patients developed late respiratory failure after 24 hours of ingestion, and all of them showed progressive RNS changes indicating severe IMS prior to intubation. Conclusion. The normal RNS in all patients developing early respiratory failure suggests that it is due to a central nervous system (CNS) and muscarinic effect. This emphasizes the need for early rapid atropinisation as a priority, combating the nicotinic effects being less urgent. This is in contrast with the late respiratory failure, which has been shown to be associated with neuromuscular dysfunction. Further studies are needed to quantify CNS and muscarinic dysfunction to assist in the development of better treatments for the severe and early OP poisoning. [ABSTRACT FROM AUTHOR]

Fertility is declining in many countries and there has been substantial interest in the potential adverse effects of exposure to environmental hazardous chemicals, including pesticides on male reproduction. Organophosphorous compounds (organophosphates, OP) constitute a heterogeneous category of chemicals specifically designed for the control of pests or plant diseases. OP are known to produce reproductive toxicity, resulting in a decrease in the fertility levels of humans and animals. This review article mainly focused on toxicity of some OP such as acephate, chlorpyrifos, diazinon, dimethoate, fenitrothion, malathion, and monocrotophos especially dealing with reproductive toxicity in males. Furthermore, this review deals with mode of action and clinical syndromes of OP. Considerable lab studies on animals concluded that OP produce adverse effects on male reproductive system. [ABSTRACT FROM AUTHOR]

Abstract: Gas-phase photocatalytic oxidation of organophosphorous compound dimethyl methylphosphonate was carried out in a flow reactor on platinized TiO2 Degussa P25. Platinization was performed by soft chemical reduction (SCR) and photodeposition (PD) techniques. Dispersion and chemical state of platinum were studied by X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). It was found that SCR gave mostly metallic platinum, whereas PD gave only Pt2+ form. During the oxidation, the state of platinum on a SCR catalyst remained unchanged, which determined its good stability. The catalyst with PD platinum deactivated quite fast due to aggregation of Pt particles. The SCR technique was found to provide better stability and activity. [Copyright &y& Elsevier]

Abstract: Diethyldithiophosphate (DEDTP) is a metabolite formed by biotransformation of organophosphorous (OP) compounds that has a longer half-life than its parental compound. Here we evaluate the effects of DEDTP on human CD4+ T lymphocytes. In vitro exposure to DEDTP (1–50μM) decreased [3H]thymidine incorporation in resting cells and increased CD25 surface expression without altering cell viability. DEDTP treatment inhibited anti-CD3/anti-CD28 stimulation-induced CD4+ and CD8+ T cell proliferation determined by CFSE dilution. Decreased CD25 expression and intracellular IL-2 levels were correlated with this defect in cell proliferation. IL-2, IFN-γ and IL-10 secretion were also reduced while IL-4 secretion was not altered. Increased phosphorylation of SOCS3 and dephosphorylation of STAT5 were induced by DEDTP after as little as 5min of exposure. In addition, DEDTP induced phosphorylation of ERK, JNK and p38 and NFAT nuclear translocation. These results suggest that DEDTP can modulate phosphorylation of intracellular proteins such as SOCS3, which functions as a negative regulator of cytokine signalling, and that DEDTP exposure may thus cause T cells to fail to respond to further antigen challenges. [ABSTRACT FROM AUTHOR]

Organophosphorous pesticides and nerve agents inhibit the enzyme acetylcholinesterase at neuronal synapses and in neuromuscular junctions. The resulting accumulation of acetylcholine overwhelms regulatory mechanisms, potentially leading to seizures and death from respiratory collapse. While current therapies are only capable of reducing mortality, elevation of the serum levels of the related enzyme butyrylcholinesterase (BChE) by application of the purified protein as a bioscavenger of organophosphorous compounds is effective in preventing all symptoms associated with poisoning by these toxins. However, BChE therapy requires large quantities of enzyme that can easily overwhelm current sources. Here, we report genetic optimization, cloning and high-level expression of human BChE in plants. Plant-derived BChE is shown to be biochemically similar to human plasma-derived BChE in terms of catalytic activity and inhibitor binding. We further demonstrate the ability of the plant-derived bioscavenger to protect animals against an organophosphorous pesticide challenge. [ABSTRACT FROM AUTHOR]

Abstract: Photocatalytic hydrogen production from water solutions of dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), and radiation protective amine WR 2721, that imitate nerve chemical warfare agents was studied for the first time. Platinized titianium dioxide Degussa P25 was used as catalyst. No significant hydrogen evolution was detected without organic electron donors – sacrificial agents. The hydrogen evolution rate was shown to grow slowly with the rise of initial DMMP concentration. The initial rate vs. DMMP concentration curve is well fitted by Langmuir–Hinshelwood (L-H) equation. The DMMP adsorption constant obtained from the L-H equation fit is markedly higher than that obtained from the Langmuir adsorption isotherm. Reactions of full destruction into inorganic products of the four organophosphorous compounds were conducted. Amounts of evolved hydrogen and carbon dioxide were completely consistent with stoichiometry of proposed reaction. There were no initial compounds and only trace of total organic carbon after the end of the reaction. Complete water purification and production of an amount of valuable hydrogen was achieved. Intermediates of DMMP oxygen-free destruction were identified by means of GC/MS. They were the same as those in the case of DMMP photocatalytic oxidation. A mechanism of hydrogen evolution that explains smaller rates of mineralization compared to photocatalytic oxidation by oxygen was proposed. [Copyright &y& Elsevier]

Organophosphorous compounds are important neuroactive molecules whose presents significant analytical challenges. New monoenzyme biosensor introduced here, is used for the measurement of the level of two organophosphorous compounds, paraoxon (POX) and ethyl parathion (EPA), in phosphate buffer. Prussian blue electrodepositionized on a graphite electrode served as a template for immobilization of monoenzyme layer. A monoenzyme layer containing choline oxidase was immobilized along with nafion and bovine serum albumin, by cross-linking with glutaraldehyde. The results revealed that the response of the proposed biosensor was linear between 5 μM and 80 μM in the presence of POX and EPA. Detection limits were 0.4 μM in both cases. Also, for the optimization of the biosensor performance, temperature and pH dependency, concentration of choline chloride as substrate of choline oxidase and incubation time were determined. The results showed that the optimum values for temperature, pH, substrate concentration and incubation time were room temperature, pH 7, 4 mM and 30 min, respectively. [ABSTRACT FROM AUTHOR]

In this paper, the thermal behaviours of two organophosphorous compounds, N, N-dimethyl- N′, N′-diphenylphosphorodihydrazidic (NDD) and diphenyl amidophosphate (DPA), were studied by thermogravimetery (TG), differential thermal analysis (DTA) and differential scanning calorimetery (DSC) techniques under non-isothermal conditions. The results showed that NDD melts about 185 °C before it decomposes. NDD decomposition occurs in two continuous steps, in the 190–410 °C temperature range. First thermal degradation stage for NDD results a broad exothermic peak in the DTA curve that is continued with a small exothermic peak at the end of decomposition process. On the other hand, applying TG-DTA techniques indicates that DPA melts about 150 °C before it decomposes. This compound decomposes in the temperature range of 230 to 330 °C in two steps. These steps are endothermic and exothermic, respectively. Activation energy and pre-exponential factor for the first step of decomposition of each compound were found by means of Kissinger method and were verified by Ozawa–Flynn–Wall method. Activation energy obtained by Kissinger method for the first stage of NDD and DPA decompositions are 138 and 170 KJ mol−1, respectively. Finally, the thermodynamic parameters (Δ G#, Δ H# and Δ S#) for first step decomposition of investigated organophosphorous were determined. [ABSTRACT FROM AUTHOR]

Phosphorous compounds are one of most important class of ligands that are used in synthesis, catalysis and other processes. The coarse adjustment of electrodonative character of phosphorous can be done by switching to phosphonates or phosphinates with consecutive transformation. However fine tuning of phosphorous atom by variation of adjacent functional groups might be a serious problem due to reactivity of those. An alternative introduction of aromatic and vinylic groups can be done by P–C coupling reactions. Here I'd like to present a brief overview of published catalytic systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Organophosphate poisoning may precipitate complex ventricular arrhythmias, a frequently overlooked and potentially lethal aspect of this condition. Acute effects consist of electrocardiographic ST-T segment changes and AV conduction disturbances of varying degrees, while long-lasting cardiac changes include QT prolongation, polymorphic tachycardia ("Torsades de Pointes"), and sudden cardiac death. Cardiac monitoring of organophosphate intoxicated patients for relatively long periods after the poisoning and early aggressive treatment of arrhythmias may be the clue to better survival. We present here a review of the literature with a focus on late cardiac arrhythmias (mainly "Torsades de pointes"), possible mechanisms, and treatment modalities, with special emphasis on postpoisoning monitoring for development of arrhythmias. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the detection of dimethyl methylphosphonate (DMMP), using tin dioxide-based gas sensors. One of the characteristics of this device is the functioning temperature, which ranges between 25 and 500°C. The results presented in the first part of this paper concern the study of the thermal degradation of DMMP vapours, in particular the identification and quantification of light and heavy degraded compounds by several analysis techniques (IR, NMR, GC). The second part of this paper is dedicated to the interpretation of the gas sensor''s responses during the detection of DMMP and the determination of the origin of the electrical response of the sensor. Finally in the third part of this paper, we propose a reactional mechanism which describes the interactions between DMMP vapours and SnO2 surface, that occurs during the detection of this phosporous compound. [Copyright &y& Elsevier]