2-phenoxybenzoic Acid Research Articles

Sphingobium phenoxybenzoativorans sp. nov., a 2-phenoxybenzoic-acid-degrading bacterium.

A Gram-stain-negative, aerobic, yellow-pigmented, rod-shaped bacterium, designated strain SC_3T, was isolated from pesticide-contaminated soil sediment. The strain was able to mineralize 2-phenoxybenzoic acid. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SC_3T formed a monophyletic lineage in the genus Sphingobium, and showed highest similarity to the type strains of Sphingobium abikonense (97.0 %), followed by Sphingobium lactosutens (96.8 %) and Sphingobium cloacae (96.7 %). The DNA-DNA relatedness between strain SC_3T and its closest phylogenetic neighbours was lower than 70 %. The major fatty acids (>5 % of the total) were summed feature 8 (comprising C18:1ω7c/C18:1ω6c), summed feature 3 (comprising C16:1ω7c/C16:1ω6c), C14:0 2-OH, C16:0 and C17:1ω6c. The predominant quinone was ubiquinone Q-10, and the major polyamine was spermidine. The polar lipid profile contained diphosphatidylglycerol (DPG), sphingoglycolipid (SGL), phosphatidylethanolamine (PDME), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylmonomethylethanolamine (PMME), an unknown aminolipid (AL), two unknown lipids (L1, L2) and several unknown phospholipids (PL1-6). The genomic DNA G+C content of strain SC_3T was 62.9 mol%. On the basis of phenotypic, chemotaxonomic, phylogenetic and genotypic data, strain SC_3T represents a novel species of the genus Sphingobium, for which the name Sphingobium phenoxybenzoativorans sp. nov. is proposed. The type strain is SC_3T ( = CCTCC AB 2014349T = KACC 42448T).

SINTESIS XANTON DARI ASAM 2-PHENOXYBENZOIC ACID SEBAGAI BAHAN DASAR OBAT MALARIA BARU

Synthesis of xanthone was conducted from the raw material of 2-phenoxybenzoic acid through acid-catalyzed-cyclization. The product was characterized using UV- Vis, 1 13 d FT-IR, H-NMR, C-NMR, an LC-MS Cyclization of 2-phenoxybenzoic acid using sulfuric acid catalyt gave xanthone in 86.11 % yield. These compounds as the basis of new malaria drugs.Keywords 2-phenoxybenzoic acid, Synthesis, Xanthone, Characterized.

Fast Analysis of Synthetic Pyrethroid Metabolites in Water Samples Using In-Syringe Derivatization Coupled Hollow Fiber Mediated Liquid Phase Microextraction with GC-ECD

A fast and efficient method has been demonstrated for the trace determination of six important metabolites of synthetic pyrethroids including cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis- and trans-Cl2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Br2CA), 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA), 3-phenoxybenzoic acid (3-PBA), and 2-phenoxybenzoic acid (2-PBA) in environmental water samples using hollow fiber (HF)-mediated liquid-phase microextraction (LPME) coupled with in-syringe derivatization (ISD) followed by gas chromatography (GC) with electron capture detector (ECD) analysis. This method utilizes a HF membrane segment impregnated with extraction solvent as the LPME sampling probe, which was connected to a microsyringe pre-filled with derivatizing agents, and it was immersed into sample solution for extraction. After extraction, the extracting solution was subjected to derivatization reaction that was performed inside the syringe barrel followed by GC-ECD analysis. Under optimal conditions, the best extraction efficiency was obtained using sampling probe (2.0 cm hollow fiber) impregnated with 1-octanol immersed into water sample (5.0 mL, adjusted pH below 1.0) and stirring (1,250 rpm) for 10 min at 70 °C and diisopropylcarbodiimide (2 μL) and 1,1,1,3,3,3-hexafluoro-2-propanol (1 μL) were the derivatizing agents used. The detection limits of 3 ng mL−1 for cis- and trans-Cl2CA, 2 ng mL−1 for cis-Br2CA, 6 ng mL−1 for 4-F-3-PBA, and 0.6 ng mL−1 for 3-PBA and 2-PBA. The method showed good linearity (R2 = 0.973−0.998), repeatability from 4.0 to 13 % (n = 5), recovery from 79.2 to 95.7 %, and enrichment factors ranged between 109 and 159 for target analytes spiked in water samples. The proposed method and conventional methods were compared. Results suggested that the proposed HF-LPME-ISD/GC-ECD method was a rapid, simple, inexpensive, and eco-friendly technique for the analysis of metabolites of pyrethroids.

Synthesis of N-arylidene-2-(2-Phenoxyphenyl) Acetohydrazides as Anti-Inflammatory Agents.

Diclofenac sodium has been used for its anti-inflammatory actions for about 28 years, but since all the non-steroidal anti-inflammatory drugs (NSAIDs) suffer from the lethal gastro intestinal (GI) toxicities, diclofenac sodium is not an exception. The free -COOH group is thought to be responsible for the GI toxicity associated with all traditional NSAIDs. In the present research, the main motto was to develop new chemical entities as potential anti-inflammatory agents with no GI toxicities. A new type of 2-(2-phenoxyphenyl) acetohydrazide possessing N-arylidene substituents, was synthesized for evaluation as anti-inflammatory agents. The starting material 2-(2-Phenoxyphenyl) acetohydrazide was synthesized from 2-phenoxybenzoic acid in several steps according to the previous published method. Various substituted arylidene-2-phenoxynicotinic acid hydrazide derivatives were synthesized by the reaction of hydrazide 17 with selected aldehydes and screened for their potential anti-inflammatory activity. The structure of synthesized compounds was confirmed by different nuclear magnetic resonance technique, Fourier transform infrared spectroscopy (FTIR) and Mass-spectrometry data format. Qualitative structure-activity relationship data, acquired using the carrageenan-induced rat paw edema assay, showed that this group of arylidene-2-phenoxybenzoic acid hydrazides exhibit anti-inflammatory activity with significant reduction of rat paw edema (17-58% reduction in inflammation at different time intervals) in comparison with control group and a moderate to good activity range in comparison with diclofenac as the reference drug. Compounds 9a, 9d and 9e exhibited the most prominent and consistent anti-inflammatory activity. The compound, N-(4-Chlorobenzylidene)-2-(2-phenoxyphenyl) acetohydrazide (9d), exhibited the most in-vivo activity (32-58% reduction in inflammation) compared to the reference drug diclofenac (35-74% reduction in inflammation) in a carrageenan induced rat paw-edema assay.

Thin Films of Tb(pobz)3 (Hpobz = 2-phenoxybenzoic acid): Reactive CVD and Optical Properties

Thin films of aromatic terbium carboxylates are promising materials for application in different optical devices. However, thin films deposition of these compounds by common methods is almost impossible due to their low solubility in most common organic solvents and nonvolatility. In our previous work it was shown that thin films of one of the simplest aromatic terbium carboxylate Tb(bz)3 (Hbz - benzoic acid) can be obtained by the original approach based on the exchange reaction between volatile precursors - reactive CVD (RCVD). Herein we improved this approach and demonstrated its possibilities and advantages on deposition of thin films of new emissive material - Tb(pobz)3 (Hpobz - phenoxybenzoic acid). The bulk products and thin films of Tb(pobz)3, obtained by RCVD method were characterized by elemental analysis, IR-, Raman and photoluminescent spectroscopy as well as thin films were studied by AFM and SEM techniques.

OLEDs based on some mixed-ligand terbium carboxylates and zinc complexes with tetradentate Schiff bases: Mechanisms of electroluminescence degradation

Mixed-ligand terbium carboxylates—Tb(Carb) 3(TPPO) 2 (HCarb = HSal (salicylic acid), Hpobz (2-phenoxybenzoic acid); TPPO = triphenylphosphine oxide) and zinc complexes with tetradentate Schiff bases—ZnSB (H 2SB = H 2SAL1, H 2SAL2 (derivatives of salicylic aldehyde); H 2MO1, H 2MO2 (derivatives of o-vanillin)) were used as electroluminescent (EL) layers in organic light emitting diodes (OLEDs). These devices have undergone reversible and irreversible mechanisms of EL degradation. The reversible one is mainly associated with charge carrier trap filling. At the same time several mechanisms of irreversible degradation were observed under UV light irradiation, heating and ageing in ambient conditions. The degradation mechanisms of OLEDs under heating from 293 K to 320 K were related to the changes in the interface regions. The initial degradation was eliminated by (1) an application of alternating bias voltage; (2) a decrease of the substrate temperature and the velocity of the thermal evaporation of materials. The degradation of OLEDs was not observed under low UV irradiation that is promising for OLEDs operation under day light.

Direct laser desorption/ionization mass spectrometry characterization of some aromatic lanthanide carboxylates

Abstract The composition of some aromatic terbium carboxylates TbL 3 (HL = Hpobz: 2-phenoxybenzoic acid; HPA: phenylanthranylic acid; HSal: salicylic acid; Habz: anthranylic acid) and their mixed-ligand complexes TbL 3 (TPPO) n (TPPO: triphenylphosphine oxide; n = 1, 2) was studied by direct laser desorption/ionization mass spectrometry (LDI MS). The influence of the ligands composition on the oligomerization of complex molecules and stability of oligomeric ions during LDI MS experiment was established.

Microwave‐Assisted Synthesis of 2‐Phenoxybenzoic Acids

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Microwave-Assisted Synthesis of 2-Phenoxybenzoic Acids

Substituted 2-phenoxybenzoic acid derivatives were synthesised in high yield and in short reaction times using the Ullmann condensation of 2-chlorobenzoic acid with phenol derivatives under microwave irradiation in dry media.

Synthesis and Analgesic Activity of 2-Phenoxybenzoic Acid and N-Phenylanthranilic Acid Hydrazides

A series of 2-phenoxybenzoic acid and N-phenylanthranilic acid hydrazides were synthesized and evaluated for their analgesic activities. Several compounds were significantly more potent than mefenamic acid and diclofenac sodium in abdominal constriction and formalin tests.

2-Phenoxybenzoic acid at room temperature

In the crystal structure of the title compound, C13H10O3, the mol­ecules form classical hydrogen-bonded carboxylic acid dimers [O⋯O = 2.651 (2) A]. These dimers are linked by C—H⋯π and π–π inter­actions to give a three-dimensional network.

New gas chromatographic–mass spectrometric method for the determination of urinary pyrethroid metabolites in environmental medicine

We have developed and validated a new, reliable and very sensitive method for the determination of the urinary metabolites of the most common pyrethroids in one analytical run. After acidic hydrolysis for the cleavage of conjugates, the analytes cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid ( cis-Cl 2CA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid ( trans-Cl 2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (Br 2CA), 4-fluoro-3-phenoxybenzoic acid (F-PBA) and 3-phenoxybenzoic acid (3-PBA) were extracted from the matrix with a liquid–liquid extraction procedure using n-hexane under acidic conditions. For further clean-up, NaOH was added to the organic phase and the carboxylic acids were re-extracted into the aqueous phase. After acidification and extraction into n-hexane again, the metabolites were then derivatised to volatile esters using N- tert.-butyldimethylsilyl- N-methyltrifluoroacetamid (MTBSTFA). Separation and detection were carried out using capillary gas chromatography with mass-selective detection (GC–MS). 2-Phenoxybenzoic acid (2-PBA) served as internal standard for the quantification of the pyrethroid metabolites. The limit of detection for all analytes was 0.05 μg/l urine. The RSD of the within-series imprecision was between 2.0 and 5.4% at a spiked concentration of 0.4 μg/l and the relative recovery was between 79.3 and 93.4%, depending on the analyte. This method was used for the analysis of urine samples of 46 persons from the general population without known exposure to pyrethroids. The metabolites cis-Cl 2CA, trans-Cl 2CA and 3-PBA could be found in 52, 72 and 70% of all samples with median values of 0.06, 0.11 and 0.16 μg/l, respectively. Br 2CA and F-PBA could also be detected in 13 and 4% of the urine samples.

Substituted Xanthones as Antimycobacterial Agents, Part 1: Synthesis and Assignment of1H/13C NMR Chemical Shifts

A series of substituted xanthones was synthesized in order to prove the hypothesis that electron-withdrawing substituents enhance the antimycobacterial activity of these compounds, which is described by means of a QSAR equation with 13C NMR chemical shifts as independent parameters. The key step of the synthesis is the formation of substituted 2-phenoxybenzoic acids by Ullmann reaction followed by intramolecular Friedel-Crafts acylation, leading to methyl-, carboxy-, nitro-, cyano-, and aminoxanthones as a test set for QSAR investigations. Spectroscopic data (1H and 13C chemical shifts, IR, UV) of these xanthones are presented and analyzed. Specific shift increments for xanthones depending on the substituent position and on the position of the respective proton/carbon atom as well as additivity rules were developed.

Synthesis and characterization of new titanium hexanuclear oxo carboxylato alkoxides. Molecular structure of [Ti6(μ3-O)6(μ-O2CC6H4OPh)6(OEt)6

The reaction between Ti(OR)4 (R = Et or Pri) and 2-phenoxybenzoic acid in refluxing toluene led to [Ti6(µ3-O)6(µ-O2CC6H4OPh)6(OR)6]; its structure corresponds to an assembly of two staggered triangular units sharing six edges (actually the µ3-O ligands) and connected via the carboxylate ligands.

Determination of trace levels of pyrethroid metabolites in human urine by capillary gas chromatography-high resolution mass spectrometry with negative chemical ionization

Applications of high-resolution gas chromatography and high-resolution mass spectrometry (GC-MS) for identification and quantitation of trace amounts of pyrethroid metabolites in human urine samples are demonstrated. The method covers the pyrethroid metabolitescis- andtrans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane carboxylic acid (cis- andtrans-DCCA),cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DBCA), 4-fluoro-3-phenoxybenzoic acid (FPBA), and 3-phenoxybenzoic acid (3-PBA). After acid-induced hydrolysis of urine samples and exhaustive solvent extraction, a carbodiimide-coupled esterification of the free carboxylic acids with hexafluoroisopropanol (HFIP) is applied. Identification of the derivatives formed is achieved by low-resolution electron-impact mass spectrometry (EIMS) using an ion-trap detector. Quantitation was by capillary gas chromatography—high-resolution mass spectrometry using negative chemical ionization (GC-NCIMS). 2-Phenoxybenzoic acid (2-PBA) served as internal standard. The limits of detection forcis- andtrans-DCCA,cis-DBCA, FPBA and 3-PBA were 0.03 μg L−1 or below. The applicability of the presented method was tested on urine samples of persons exposed to low levels of pyrethroids.

Analytical method for the determination of urinary 3-phenoxybenzoic acid in subjects occupationally exposed to pyrethroid insecticides

The determination of urinary 3-phenoxybenzoic acid enables exposure to pyrethroid insecticides to be evaluated. A method for the quantitative determination of this metabolite in urine is described. The compound and the internal standard (2-phenoxybenzoic acid) are derivatized with pentafluorobenzylbromide and transformed into pentafluorobenzyl esters, which are determined by gas chromatography with an intermediate polarity capillary column and an electron-capture detector. Before GC analysis, the urinary extracts are purified on LC-Si SPE columns. The proposed method has a detection limit of 0.5 μg/l and a mean recovery of 91.3%. The coefficient of variation of the analytical procedure, evaluated at a concentration of 24.96 μg/l, was 9.58%. Storage of the urine samples for 3 months at −18°C did not lead to significant changes in the concentration of analyte. The method was tested analysing the urine of a farm worker with symptoms of pyrethroid poisoning, occupationally exposed to esfenvalerate.

Determination of metabolites of pyrethroids in human urine using solid-phase extraction and gas chromatography–mass spectrometry

The described method permits the determination of the five most important metabolites of the pyrethroids permethrin, cypermethrin, deltamethrin, λ-cyhalothrin, fenvalerate, phenothrin and β-cyfluthrin in human urine in one run. The major urinary metabolites of these substances are cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid ( cis-Cl 2CA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid ( trans-Cl 2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (Br 2CA), fluoro-3-phenoxybenzoic acid (F-PBA) and 3-phenoxybenzoic acid (3-PBA). After acidic hydrolysis to release the conjugated carboxylic acid metabolites, the analytes were separated from the matrix by means of solid-phase extraction using a reversed-phase column. The components of the eluate were converted to their methyl esters and extracted in hexane. Separation and quantitative analysis of the pyrethroid metabolites was carried out by capillary gas chromatography and mass selective detection. 2-Phenoxybenzoic acid served as an internal standard. The detection limits lay between 0.3 and 0.5 μg per litre urine. The relative standard deviations of the within-series imprecision were between 1% and 6%. The relative recovery rates ranged between 90% and 98%. Using this method we determined the elimination of pyrethroid metabolites in 24-h urine samples from eight pest controllers after indoor application of permethrin. The detected concentrations ranged from 1 to 70 μg g −1 creatinine.

Nucleophilic substitution inO-phenyldibenzofuranium and 10-phenylxanthonium cations

Reactions ofO-phenyldibenzofuranium tetrafluoroborate with nucleophiles (OH−, NO2 −, AcO−) in aqueous media follow the SNAr-mechanism and involve dehydroarenes. In DMSO, this salt smoothly reacts with NO2 − and I− with predominant opening of the furan ring. 10-Phenylxanthonium tetrafluoroborate readily arylates the NO2 − ion in water (at the N and O atoms), mainly with predominant opening of the central ring, and is completely decomposed even with weak bases (NH2OH, 2,4-dinitrophenylhydrazine). The Bayer—Villiger oxidation of this salt affords xanthone and 2-phenoxybenzoic acid.

Copper(II) carboxylate-carboxylic acid adducts: The crystal and molecular structure of tetrakis-[μ-(2-phenoxybenzoato-O,O′)]bis[(2-phenoxybenzoic acid)copper(II)

The crystal structure of the carboxylic acid adduct of a tetracarboxylate-bridged dimeric species, [Cu2(RCO2)4(RCO2H)2], where RCO2H = 2-phenoxybenzoic acid, has been determined by X-ray diffraction and refined to a residual R = 0.037 for 2827 observed reflections. The centrosymmetric dimer has a CuCu separation of 2.602(1) Å, a mean CuO (plane) bond length of 1.960(3) Å and a CuO (axial) length of 2.182(3) Å, to the adducted acid molecule. The acid proton is hydrogen bonded to a cage carboxylate oxygen (O---O, 2.64(1) Å).

The Electronic Effect of the Substituents on the Intramolecular Hydrogen Bonding of o-Aryloxybenzoic Acids

Abstract The infrared hydroxyl and carbonyl absorptions of o-aryloxybenzoic acids have been reported and the assignment of each absorption band in these regions made. The higher carbonyl-stretching absorptin at about 1752 cm−1 has been attributed to the intramolecular hydrogen-bonded trans isomer from the following reasons: i) The Ai⁄Ac intensity ratio in the hydroxyl-stretching region increases as the Hammett σ-constant of the substituent decreases, and the same tendency is observed by assigning the carbonyl band at a higher frequency to the trans isomer; ii) From the measurement of the absorption intensity of 2-phenoxybenzoic acid at various temperatures, in both the hydroxyl and carbonyl regions, the authors have obtained nearly equal enthalpy difference values (1.89 and 1.78 kcal./mol. respectively) between the cis and trans isomers by assuming the above assignment.