Mono Ethylene Research Articles

Potential bio-herbicide from Streptomyces sp. KR0005 to control weeds in a horticultural field

ABSTRACT Herbicidal active metabolites obtained from actinomycetes provide valuable sources in the search for new candidates. They might be striking alternatives to synthetic herbicides. In the present study, actinobacteria strains were isolated from soil samples and their herbicidal activities were screened. In the screening, Streptomyces sp. strain KR0005 broth culture exhibited the highest phytotoxic activity. Thus, it was selected for further studies. The herbicidal active compound purified from this selected strain was identified as cycloheximide (MW, 281.; C15H23NO4) based on 1H-NMR, 13C-NMR, 2D-NMR, and high-resolution electrospray ionisation mass spectrometry analyses. Dose–response experiments revealed that the GR50 value of Digitaria ciliaris was 1.37 g L−1 to Streptomyces sp. strain KR0005 culture filtrate. In general, the inclusion of v/v 0.1% of LES270 (Alcohols, (C12-14), ethoxylated, mono ethers with sulphuric acid, sodium salts) and SF90 (Alcohols, C12-14-secondary, ethoxylated) surfactants resulted in a 14.3% decrease and a 24.1% increase in herbicidal activity, respectively, compared with Tween-20 (Polyoxyethylene sorbitan monolaurate). Mode of action experiments revealed that the KR0005 culture filtrate acted as both photosynthesis and cell membrane integrity inhibitors in a dose-dependent manner. However, further studies such as mutation and/or specific culture conditions are needed to increase the herbicidal activity of this selected strain.

The Removal of Hydrophobic Matter from Thermosensitive Poly[oligo(ethylene glycol) Monomethyl Ether Acrylate] Gel Adsorbent in Alcohol-Water Mixtures.

A thermosensitive gel that exhibits lower critical solution temperature (LCST) becomes hydrophilic at low temperatures and hydrophobic at high temperatures in water. A system for absorbing hydrophobic organic matters that exploits this property has been reported. While washing the gel at a low temperature with a good solvent is a possible method for removing the adsorbed matter, a process that then shrinks the gel is also required. Herein, we focused on poly[oligo(ethylene glycol) mono(m)ethyl ether acrylate] (POEGA) gels as thermosensitive gels suitable for use in this system. POEGAs are known to contain poly(ethylene glycol) (PEG) units in their side chains and exhibit upper critical solution temperature (UCST) behavior in aliphatic alcohols. By exploiting this property, we developed a method for removing hydrophobic matters that accumulate in these gels; we also evaluated the LCST and UCST behavior of POEGA gels in alcohol–water mixtures, and measured the LCSTs of these gels in water and their UCSTs in some alcohols.

Structural, magnetic and adsorptive properties of nano spinel of cobalt aluminate doped with nickel for Cr(VI) removal

Nanocrystallines of cobalt aluminate spinel doped with Nickel (MAl2O4; M = Co+2, Ni+2) were synthesized by sol-gel method. The MAl2O4 samples were prepared by using aluminum nitrate; cobalt nitrate, nickel nitrate, citric acid and diethylene glycol mono ethyl ether as precursor materials. The nanocrystallines spinel were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction(XRD), Thermal gravimetric (TGA), Scanning electron microcopy (SEM) with the energy dispersive X-ray spectroscopy (EDX) methods. The Specific surface area of the synthesized powders was measured with a Brunauer-Emmet-Teller (BET) apparatus using N2 adsorption. According to obtained XRD patterns the formation of single phase MAl2O4 completed up 800 °C. The average crystallite's sizes spinel and specific surface area at 800 °C were estimated about 11.07 nm and 154 m2 g−1, respectively. The results of SEM analysis show that the nanoparticles shape are as spherical shape, uniform and a little agglomerated. The magnetic behavior of spinels showed the magnetization decreased with increasing nickel ions. Adsorption of Cr(VI) by as prepared spinels were considered. The highest percent of Cr(VI) adsorption was occurred at contact time of 45 min, pH 7.0, and adsorbent dose of 2 g L−1. The order of adsorption capacity of sorbent samples for Cr(VI) removal was as follow: Ni0.5Cu0.5Al2O4 >Ni0.7Cu0.3Al2O4 >Ni0.3Cu0.7Al2O4>NiAl2O4> CoAl2O4. Kinetic studies indicated that the adsorption process follows by pseudo second-order model. Thermodynamic results revealed that the adsorption of Cr(VI) is endothermic, spontaneously process and feasible in the range of 298–338 K.

Effect DEHP plasticizer on MDA concentration and histopathological changes in Contronix contronix japonica

In this experiment, we aimed to recorded the effect of chronic oral exposure to DEHP on lipid peroxidation and histopathological lesions induced in different organs. A total of 150 quail chick divided into two groups (75 quail’s chicks at each group), control group left without any treatment all time, the second group was orally administrated 5% of DEHP (278.05 mg/kg bw) three times per week and lasted for 60 days. At 30 and 60 days old, a total number of 25 from both groups were euthanized. Blood samples were collected to determine the serum concentration of DEHP and mono ethyl hexyl phthalate (MEHP), liver and kidney to estimate tissue concentration of malondialdehyde (MDA), samples from different organs for histopathological examination. The result showed that the concentration of DEHP and MEHP in blood's serum and concentration of MDA in liver and kidney significantly increased with time in comparison with the control group; besides, oral administration of DEHP induced sever pathological lesions, in brain, aorta, intestines, liver, lung, ovary and testis. In conclusion, the DEHP and its metabolic product MEHP significantly increased in serum and cause significant increase in concertation of MDA in liver and kidney tissues, produces a significant histopathological change in brain, aorta, liver, intestine, lung, ovary and testis that can cause a life-threatening condition.

Effect of Ether Mono Amine Collector on the Cationic Flotation of Micaceous Minerals—A Comparative Study

Micaceous minerals, known as layer silicates, are counted mostly as the gangue minerals associated with valuable minerals, especially iron oxides. They mainly reject through the reverse flotation process using the cationic collectors, e.g., ether amines, to improve process sustainability. Although ether amines have been applied for floating the wide range of silicates, few investigations explored their adsorption behaviors on the micaceous minerals. In this study, flotation of phlogopite, biotite, and quartz (for comparison purposes) in the presence of Flotigam®EDA (EDA) (commercial ether monoamine collector), at pH 10 was investigated through the single mineral micro–flotation experiments. Adsorption behaviors were explored by the contact angle, residual surface tension measurements, and zeta potential analyses. Micro–flotation outcomes indicated that the quartz floatability was more than phlogopite and biotite. In the presence of 30 mg/dm3 EDA, their recoveries were 97.1, 46.3, and 63.8%, respectively. Increasing EDA concentration made a substantial increase in micaceous minerals’ floatability. Adsorption assessments confirmed that increasing the EDA concentration resulted in higher adsorption of EDA onto the surface of micaceous minerals than the quartz (all by physical adsorption). Such a behavior could be related to the nature of micaceous minerals, including their layer structure and low hardness.

Nanoscale stereometric and fractal evaluation of clathrate formation at quartz surface by atomic force microscopy

The clathrate formation on quartz crystal surface has been analyzed extensively by means of contact angle, Atomic Force Microscopy (AFM) measurements as well as by Fractal Theory (FT). Stereometric and fractal parameters were obtained from topographic maps by AFM and have extensively studied. The main goal was to study the influence of clathrate formation on the morphology and texture of quartz monocrystal conditioned with starch and mono ether amine acetate and the wetting characteristics of the quartz surface. The polished sections were initially conditioned in the isolated presence of each reagent and in the presence of their mixtures and at pH = 10.5. After a sequence of conditioning stages, the quartz surface analyses were carried out ex-situ obtaining the AFM images were by tapping mode. In the presence of a combination of flotation reagents under different conditions, 2D topographic maps, morphology photosimulations, and 3D topographic details revealed that there was formation of agglomerates on the surface of the monocrystal for quartz surface conditioned initially with starch (100 mg L−1) and with addition of the mono ether amine acetate (50 mg L−1). However, for the mixture containing higher concentrations of starch (1000 mg L−1) was found a more organized structure, with the presence of smaller clusters. Thus, the increase in the concentration of starch promoted the formation of clathrate, indicating that mono ether amine acetate interacts more strongly with starch than with the surface of the monocrystal. This phenomenon also has decreased the quartz contact angle that changed from 62° to 24°, in the presence of mono ether amine (50 mg L−1) and for the mixture containing higher concentrations of starch (1000 mg L−1 corn starch + 50 mg L−1 mono ether amine), respectively. Fractal theory proved to be an excellent tool for studying the complexity of surfaces and for improving processes for obtaining materials, in mineral processing and the other industries. Evidence has been provided indicating that co-adsorption through binary interactions between starch and amines by chemical complexation. Starch cages, that behaviour as a host guest molecule, leading to the amine molecules to penetrate them forming cluster.

Aqueous olefin hydroformylation using water-soluble mono- and trinuclear N,O-chelate rhodium(I)-aryl ether precatalysts

Water-soluble, sulfonated, salicylaldiminato-aryl ether mono- (7) and trimeric (8) ligands were prepared and reacted with the [Rh(μ-Cl)(η2:η2−COD)]2 dimer to yield the corresponding water-soluble mononuclear (9) and trinuclear (10) Rh(I) complexes. These rhodium complexes were evaluated and are active as catalyst precursors in the aqueous biphasic hydroformylation of 1-octene and styrene. Optimal conditions were realised, using 1-octene as a model substrate, at 85 °C and a syngas pressure of 50 bar, where the best activity and chemoselectivity for aldehydes was obtained. Catalyst recycling was successfully conducted over 5 cycles in a biphasic medium, with a gradual loss in catalytic performance for both complexes. However, the dendrimer-stabilised trinuclear precatalyst (10) showed improved recyclability during “neat”, aqueous monophasic hydroformylation experiments, while the mononuclear precatalyst (9) showed a reduced overall performance. Both precatalysts showed sustained catalytic activity (> 450 h−1) and a total bias towards aldehyde chemoselectivity during the aqueous biphasic hydroformylation of styrene.

Исследование каталитической активности K2CO3 в реакции карбоксилирования фенола натрийэтилкарбонатом

The catalуtic activitу of К2СО3 in the carboxуlation reaction of phenol with sodium ethуl carbonate has been investigated. The aim of the research was to develop a new efficient method for producing salicylic acid which is widely used in pharmaceuticals and other type preparations, also used in agriculture as an effective plant growth promoter. The most widespread synthesis method of salicylic acid is the Kolbe-Schmitt of phenol carboxylation, but it has a number of serious disadvantages. One of the alternative methods is the use of alkali metal salts of mono ethers of the carbonic acids as carboxylating agents in the carboxylation of phenol. In order to improve the method of production of salicylic acid, the catalytic activity of the К2СО3 catalyst at the carboxylation of phenol with sodium ethyl carbonate was studied for the first time. The effect of the process parameters (temperature, pressure, reaction time, ratio of catalyst to carboxylating agent) on the yield of the target product was studied. It was found optimal conditions: T=160°C, PCO2=10 atm, τ=7(4+3) h, [К2СО3]:[SEC]=0.07:1 at which the yield of the target product was 80%. The yields of the target product at phenol carboxylation with sodium ethyl carbonate in the presence and without K2CO3 were determined. It was found that К2СО3 shows the catalytic activity during carboxylation reaction.

On the kinetics of multiphase etherification of glycerol with isobutene

The etherification of the hydroxyl groups of glycerol with isobutene successively forms mono-ethers (ME), di-ethers (DE) and tri-ether (TE) of glycerol, which are desired fuel additives. The initial rates of each step in the consecutive etherification were measured independently under various concentrations and temperatures. The initial rate of ME synthesis from glycerol and isobutene was independent of the initial composition due to the invariant concentrations of reactants in the reaction phase. Adding ME to the glycerol-isobutene reaction was observed to accelerate the glycerol conversion by enhancing the solvation of isobutene in glycerol. Rate expressions in the form of power-law with parameters regressed from initial rates measured separately for each etherification step were found to be unable to predict the kinetics of complex reaction where all reaction steps coexisted together. This signifies significant interaction of reactions and competitive adsorption of reactants. Glycerol etherification with isobutene under high conversions where all reactions and reactants exist simultaneously was carried out to obtain kinetic data containing the interactions between different reactions. Thereafter a model considering phase separation and competitive adsorption was proposed and correlated with the initial rates and kinetic data under high conversions. The model was capable to describe all observed kinetics.

Association between exposure to a mixture of phenols, pesticides, and phthalates and obesity: Comparison of three statistical models

BackgroundThe evaluation of the chemical impact on human health is usually constrained to the analysis of the health effects of exposure to a single chemical or a group of similar chemicals at one time. The effects of chemical mixtures are seldom analyzed. In this study, we applied three statistical models to assess the association between the exposure to a mixture of seven xenobiotics (three phthalate metabolites, two phenols, and two pesticides) and obesity. MethodsUrinary levels of environmental phenols, pesticides, and phthalate metabolites were measured in adults who participated in the U.S.-based National Health and Nutrition Examination Survey (NHANES) from 2013 to 2014. Body examination was conducted to determine obesity. We fitted multivariable models, using generalized linear (here both logistic and linear) regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models to estimate the association between chemical exposures and obesity. ResultsOf 1269 individuals included in our final analysis, 38.5% had general obesity and 58.0% had abdominal obesity. In the logistic regression model established for each single chemical, bisphenol S (BPS), mono (carboxyoctyl) phthalate (MCOP), and mono (2-ethyl-5-carboxypentyl) phthalate (MECPP) were associated with both general and abdominal obesity (fourth vs. first quartile). In linear regression, MCOP was associated with BMI and waist circumference. In WQS regression analysis, the WQS index was significantly associated with both general obesity (OR = 1.63, 95% CI: 1.21–2.20) and abdominal obesity (OR = 1.66, 95% CI: 1.18–2.34). MCOP, bisphenol A (BPA), bisphenol S (BPS), and mono ethyl phthalate (MEP) were the most heavily weighing chemicals. In BKMR analysis, the overall effect of mixture was significantly associated with general obesity when all the chemicals were at their 60th percentile or above it, compared to all of them at their 50th percentile. MCOP, BPA, and BPS showed positive trends. By contrast, MECPP showed a flat and modest inverse trend. ConclusionWhen comparing results from these three models, MCOP, BPA, and BPS were identified as the most important factors associated with obesity. We recommend estimating the joint effects of chemical mixtures by applying diverse statistical methods and interpreting their results together, considering their advantages and disadvantages.

Formal Synthesis of Borrelidin: A Highly Enantio- and Diastereoselective Access to the Morken’s C2–C12 Intermediate

Abstract In contrast to methyl and isobutyl phenyl sulfone, condensing under basic conditions higher alkyl sulfones and trans-2,3-epoxy-butanol 13c (or its O-benzyl and O-silyl derivatives) proved unfeasible, a difficulty that was overcome by using mono ethers of trans-2,3-epoxy-butane-1,4-diol 35c as the electrophilic reagents. Thus, adding excess BuLi to a mixture of the benzyl ether 35b and sulfone ent-12a, a stereodiad sulfone prepared in pure state from the R-Roche ester, via the O-trityloxy-sulfone ent-12c (X-ray), gave, after elimination by column chromatography of the side-formed regioisomer, a diol-sulfone that was next converted to sulfone 20 by means of conventional functional-group modifications. Reacting likewise this sulfone with the parent O-PMB derivative 35a, and then proceeding to the same purification process and function adjustment, delivered the title fragment in virtually pure state.

Hormonal Changes at Early Age and Prenatal Exposure to Phthalates and Bisphenol A in a Cohort of Cuernavaca, Morelos, Mexico

Has been suggested that phthalate and BPA A exposure in utero may impact hormone concentrations and evolve the onset of early puberty. The objective of this study was to evaluate the association between prenatal exposures to phthalates and hormonal levels at 9 years old in a Cuernavaca, Morelos birth cohort (POSGRAD study). In a subsample of 314 children, total testosterone hormone levels and dehydroepiandrosterone sulfate (DHEA-S) were measurements from serum samples at 9 years of age from both sex. These levels were contrasted with the concentrations of 9 different metabolites of phthalates [Mono-2-ethylhexyl phthalate (MEHP), Mono-2-ethyl-5-carboxypentyl phthalate (MECPP), Mono-2-ethyl-5-hydroxyethyl phthalate (MEHHP ), Mono-2-ethyl-5-oxohexyl phthalate (MEOHP), Mono-3-carboxypropyl phthalate (MCPP), Monobenzyl phthalate (MBzP), Monobutyl phthalate (MBP), Mono-iso-butyl phthalate (MiBP) and Mono ethyl phthalate (MEP)], and Bisphenol A in urine resulting from samples of mothers during the second trimester of pregnancy, through a multiple linear regression model adjusted for anthropometric variables of the child and sociodemographic characteristics.RESULTS. A significant relationship was observed with the LnMECPP and LnMEHHP with total testosterone levels, (increase of 13%, IC95%: 0.9%, 24%, and 11% increase, IC95% 0.16% to 23.6% en IU / L, by unit of increase in each metabolite, respectively. No metabolite showed a statistically significant association with DHEA-S levels, however, in girls who initiated menarche at 9 years old, significant association were observed with MiPB, MBzP and BPA with an increase of DHEA-S.DISCUSSION. Our results are consistent with previous studies in which it has been suggested that prenatal exposure can to induce can lead to early puberty. In our case, the exposure window was during the second trimester suggesting more prevention in this stage of life.

The nature of hematite depression with corn starch in the reverse flotation of iron ore

The function of corn starch and the significance of the order of addition of corn starch and mono ether amine in the reverse flotation of iron ore has been investigated. Understanding hematite depression with starch and the corresponding hydrophilic state involves consideration of adsorption with amine as well as flocculation of fine hematite. Captive bubble contact angle and micro-flotation experiments indicated that amine has an affinity towards both hematite and quartz, and that the role of starch is to hinder the adsorption of amine at the hematite surface so that flotation is inhibited. Micro-flotation results confirmed that quartz does not have affinity towards starch at pH 10.5. In addition to competitive adsorption, flocculation of fine hematite occurs and images from high resolution X-ray computed tomography (HRXCT) and cryo-SEM reveal further detail regarding floc structure. These results provide substantial evidence that the fine hematite particles are flocculated in the presence of corn starch, and flocculation is dependent on the particle size of hematite, with greater flocculation for finer particles. Thus, starch is playing a dual role in the reverse flotation of iron ore, acting as a depressant by hindering amine adsorption at the hematite surface in order to maintain the hydrophilic surface state of hematite, and acting as a flocculant to aggregate fine hematite particles, which if not flocculated, could diminish the flotation separation efficiency by being transported to the froth phase during reverse flotation.

Синтез и цереброваскулярная противоишемическая активность новых производных 5-гидроксиадамантан-2-она

Проведен синтез и фармакологическое изучение новых производных 5-гидроксиадамантан-2-она с гетероароматическими, ароматическими и алифатическими кислотами (никотиновой, янтарной, пара-хлорфеноксиуксусной, 3,4,5-триметоксибензойной и анисовой) с целью поиска соединений, обладающих цереброваскулярной противоишемической активностью и не оказывающих гипотензивного действия. Наиболее выраженное влияние на мозговое кровообращение в условиях ишемии мозга оказывают эфиры янтарной кислоты 5-гидроксиадамантан-2-она (диэфир — Iа и моноэфир — Iб по 100 мг/кг внутривенно). Они не понижают уровень артериального давления, а моноэфир менее токсичен, LD50 740,0 (676,0 – 804,0) мг/кг. Анализ цереброваскулярного эффекта эфиров янтарной кислоты 5-гидроксиадамантан-2-она с помощью бикукуллина выявил участие ГАМК-ергического механизма сосудов мозга в его реализации. Однако методом радиолигандного анализа in vitro с использованием специфического лиганда [3H]-SR 95531 взаимодействие этих эфиров с ГАМКА-рецепторами мембран мозга крыс показано не было. Таким образом, моноэфир янтарной кислоты 5-гидроксиадамантан-2-она обладает выраженной цереброваскулярной противоишемической активностью и не оказывает гипотензивного эффекта. Последнее его выгодно отличает от используемых в неврологии препаратов (пикамилона, мексидола, нимодипина, циннаризина и кавинтона).

Liquid–liquid–solid mass transfer and phase behavior of heterogeneous etherification of glycerol with isobutene

Previous experiments observed auto‐acceleration in the etherification of glycerol with isobutene. This article engaged to uncover the reason for this phenomenon via investigating the heterogenicity, including liquid–liquid phase equilibrium and liquid–liquid–solid mass transfer, of the reaction system. Phase behavior analysis showed that the reaction mixture separates into two liquid phases during the whole course of the reaction. The produced mono ethers of glycerol thermodynamically promote the homogenization of the two liquid phases. The modeling results of liquid–liquid–solid mass transfer indicated that the resistance of mass transfer is insignificant during the reaction. The bulk compositions of the two liquid phases are very close to their corresponding equilibrium compositions. An increase of isobutene concentration in the reaction phase is believed to lead all reactions speeding up. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2526–2535, 2018

Redox Equilibration Observed for the Reduction of a Ruthenium(III) Complex by Ascorbate under Low‐Driving‐Force Conditions

A detailed kinetic study of the reduction of trans‐[RuCl2(dipicOEt)2]–, where dipicOEt = dipicolinate mono ethyl ester anion, by l‐ascorbic acid that leads to the formation of the corresponding RuII complex, was carried out spectrophotometrically using the stopped‐flow technique. The reaction was studied as a function of [AscH2]T and pH. The observed kinetic traces could only be fitted by a three‐exponential function, characteristic of three parallel reaction paths. The complex was isolated as {[Na(H2O)2][trans‐RuCl2(dipicOEt)2]}n, of which a single‐crystal X‐ray diffraction structure was determined. Detailed spectroscopic studies on the complex in aqueous solution showed that, under the selected experimental conditions, only a single complex species is present in solution. The observed complication is suggested to arise from the low driving force of the reaction during which the reoxidation of RuII by the semioxidized l‐ascorbic acid, that is, ascorbyl radical Asc·–, accounts for the apparent three‐exponential behavior of the reaction. The results are in excellent agreement with those of a recent study on the same reaction for cis‐dichloridobispicolinatoruthenate(III) (Eur. J. Inorg. Chem. 2016, 5380–5386).

Fundamental issues on the influence of starch in amine adsorption by quartz

Apart from being a resource for iron/steel production, the iron oxide mineral, hematite, is used in the paint, cosmetics, and other industries as a pigment. Reverse flotation of quartz from hematite is used extensively in the processing of iron ore containing quartz as the gangue mineral. It has been observed that depression of quartz takes place when excessive starch is used in the reverse flotation of iron ore, thus reducing the grade of the hematite concentrate. In the present work, the reason for the depression of quartz in the presence of excess starch has been investigated. Contact angle, bubble attachment time, quartz crystal micro balance with dissipation (QCM-D), and sum frequency vibrational spectroscopy (SFVS) measurements have been used to examine the interaction between mono ether amine and starch, and molecular dynamics simulation (MDS) was used to visualize the interaction between the amine and starch molecules. On the basis of these measurements it appears that a clathrate interaction takes place in such a way that the starch masks the hydrophobic tail of the mono ether amine, decreasing the contact angle at the quartz surface to 43° from 62° in the presence of excess starch.

Occupational phthalate exposure and health outcomes among hairdressing apprentices.

We studied occupational exposure to phthalates from first-morning-void urine sample of hairdressing apprentices by HPLC-MS/MS analyses and association with health status. Metabolites of mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono ethyl phthalate (MEP), mono- n-butyl phthalate (MnBP) and mono-iso-butyl phthalate (MiBP) were detected in all urine samples, followed by metabolites mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-etylhexyl) phthalate (MEHP) occurring in 97.06% and 86.76% of samples, respectively. Positive associations for females were observed between MnBP and fat-free mass index (FFMI) and age; negative associations were found between MEHP, MEOHP, MEHHP, sum of MEHP, MEHHP, MEOHP and vital capacity and also between MEHP and forced vital capacity (FVC of predicted value (PV)). Lengths of exposure were associated to MnBP, MEHHP, and MEP. We also documented positive associations between anthropometry (body mass index, waist-to-height ratio (WHtR), FFMI, fat mass index) and pulmonary function FVC% of PV for females and negative associations between WHtR, waist-to-hip ratio, FFMI and ratio of forced expiratory volume in 1 s (FEV1) to FVC (FEV1/FVC). We assume that factors of occupational environment of hairdressing apprentices are affected by phthalates and resulted in negative outcomes in breathing mechanism and influence of body composition. Adipose tissue could play role as confounding factor in urine excretion of phthalates because of their lipid solubility and accumulation.

Atypical cleavage of protonated N-fatty acyl amino acids derived from aspartic acid evidenced by sequential MS3 experiments.

Lipidomics calls for information on detected lipids and conjugates whose structural elucidation by mass spectrometry requires to rationalization of their gas phase dissociations toward collision-induced dissociation (CID) processes. This study focused on activated dissociations of two lipoamino acid (LAA) systems composed of N-palmitoyl acyl coupled with aspartic and glutamic acid mono ethyl esters (as LAA(*D) and LAA(*E)). Although in MS/MS, their CID spectra show similar trends, e.g., release of water and ethanol, the [(LAA(*D/*E)+H)-C2H5OH]+ product ions dissociate via distinct pathways in sequential MS3 experiments. The formation of all the product ions is rationalized by charge-promoted cleavages often involving stepwise processes with ion isomerization into ion-dipole prior to dissociation. The latter explains the maleic anhydride or ketene neutral losses from N-palmitoyl acyl aspartate and glutamate anhydride fragment ions, respectively. Consequently, protonated palmitoyl acid amide is generated from LAA(*D), whereas LAA(*E) leads to the [*E+H-H2O]+ anhydride. The former releases ammonia to provide acylium, which gives the C n H(2n-1) and C n H(2n-3) carbenium series. This should offer structural information, e.g., to locate either unsaturation(s) or alkyl group branching present on the various fatty acyl moieties of lipo-aspartic acid in further studies based on MS n experiments.

Children’s Behavioral and social impairment in relation to prenatal exposure to phthalates

Purpose: Phthalates are non-persistent endocrine disrupting chemicals whose relationship with children’s neurodevelopment has not been fully elucidated. This study examines the relationship between prenatal phthalate exposure and potential adverse effects on child behavior. Methods: We assessed behavioral and social impairment in 3 year old children from a Canadian prospective cohort using the parents report of the Behavior Assessment System for Children-2 (BASC-2; n=815), and the Social Responsiveness Scale-2 (SRS-2; n=556). We measured 11 phthalates metabolites in maternal urine during the first trimester of pregnancy. We used multivariable linear regression to estimate the covariate-adjusted differences in child behavior scores with a doubling in di-2-ethylhexyl (DEHP), Mono butyl (MBP), Mono benzyl (MBzP), Mono ethyl (MEP), and Mono-3-carboxypropyl (MCPP) phthalates concentrations. We also examined sex-specific associations of phthalates and behaviors. Results: No consistent associations were observed with the BASC scores. Regarding the SRS, higher MBP and MCPP concentrations were significantly associated with poorer scores of social cognition. MCPP was further associated with poorer scores of social communication. For example, a doubling in MBP concentration was associated with 0.29 points (95% CI: 0.07, 0.51) worse scores in social cognition. In further analyses, sex modified associations between MBP and MEP concentrations, and social cognition, social communication, and total SRS scores, with worse scores in boys and better scores in girls (p-interaction<0.05). For instance, a doubling in MBP concentration was associated with 0.35 (95% CI: 0.09, 0.61) and 0.27 (95% CI: 0, 0.55) points worse social cognition and total scores in boys, and better scores in girls (β= -0.19, 95% CI: -0.45, 0.07 and -0.04, 95% CI: -0.32, 0.25, respectively). Conclusions: Higher prenatal phthalate concentrations were associated with social impairment in boys, but not girls.