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| InChI=1S/C8H10O/c1-6-3-4-8(9)7(2)5-6/h3-5,9H,1-2H3 |
| KUFFULVDNCHOFZ-UHFFFAOYSA-N |
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disinfectant
An antimicrobial agent that is applied to non-living objects to destroy harmful microorganisms or to inhibit their activity.
volatile oil component
Any plant metabolite that is found naturally as a component of a volatile oil.
fungicide
A substance used to destroy fungal pests.
(via aromatic fungicide )
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fungicide
A substance used to destroy fungal pests.
(via aromatic fungicide )
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View more via ChEBI Ontology
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1,3-dimethyl-4-hydroxybenzene
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NIST Chemistry WebBook
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1-hydroxy-2,4-dimethylbenzene
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ChemIDplus
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2,4-DMP
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PPDB
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2-methyl-p-cresol
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ChEBI
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4,6-dimethylphenol
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ChemIDplus
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4-hydroxy-1,3-dimethylbenzene
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ChemIDplus
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4-hydroxy-m-xylene
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ChEBI
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asym-m-xylenol
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ChEBI
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gallex
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ChemIDplus
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m-xylenol
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ChemIDplus
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105-67-9
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CAS Registry Number
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ChemIDplus
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105-67-9
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CAS Registry Number
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NIST Chemistry WebBook
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636244
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Reaxys Registry Number
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Reaxys
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Tsukatani H, Tobiishi K, Imasaka T (2009)
Simple and sensitive determination of 2,4-xylenol in surface water samples from river and sea by gas chromatography-mass spectrometry.
Bulletin of environmental contamination and toxicology 82, 153-157 [PubMed:18949436]
[show Abstract]
A simple and selective method was developed for determination of the concentration of 2,4-xylenol in river and sea water samples using gas chromatography/mass spectrometry (GC/MS). Trace amounts of 2,4-xylenol were collected in a Oasis HLB Plus cartridge, eluted with acetonitrile. The method detection limit of 2,4-xylenol was 1.4 ng/L. The trace peaks of 2,4-xylenol were found in water samples from the river and the sea, and the concentrations were all less than 1.4 ng/L. The nine peaks of the 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-xylenol, and o-, m-, p-ethyl phenol that gave the same m/z ratio were separated efficiently. | Romero A, Santos A, Vicente F (2009)
Chemical oxidation of 2,4-dimethylphenol in soil by heterogeneous Fenton process.
Journal of hazardous materials 162, 785-790 [PubMed:18602751]
[show Abstract]
Hydrogen peroxide has been used to oxidize a sorbed aromatic contaminant in a loamy sand with 195.9 g kg(-1) of organic carbon by using iron as catalyst at 20 degrees C. The 2,4-dimethylphenol (2,4-DMP) was chosen as pollutant. Because of this soil generates a slightly basic pH in contact to an aqueous phase the solubility of the iron cation was determined in absence and presence of a chelating agent (l-ascorbic acid, l-Asc) and with and without soil. From results, it was found that in presence of soil the iron cation was always adsorbed or precipitaed onto the soil. Therefore, the procedure selected for soil remediation was to add firstly the iron solution used as catalyst and following the hydrogen peroxide solution used as oxidant. As iron cation is sorbed onto the soil before the oxidant reagent is provided a heterogeneous catalytic system results. This modified Fenton runs have been carried out using 0.11 mg(2,4-DMP) g(-1)(soil) and 2.1 mg(Fe) g(-1)(soil). The H(2)O(2)/pollutant weight ratios used were 182 and 364. The results show that H(2)O(2) oxidizes 2,4-DMP producing CO(2) and acetic acid. After 20 min of reaction time a pollutant conversion of 75% and 86% was found, depending on the H(2)O(2) dosage. Moreover, it was found that hydrogen peroxide was heterogeneously decomposed by the soil (due to its organic and/or inorganic components) and its decomposition rate decreases when the iron was previously precipitated-impregnated into the soil. | Tsukatani H, Okudaira H, Uchimura T, Imasaka T, Imasaka T (2009)
Selective ionization of 2,4-xylenol in mass spectrometry using a tunable laser and supersonic jet technique.
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 25, 599-604 [PubMed:19430139]
[show Abstract]
A supersonic jet/resonance-enhanced multiphoton ionization/time-of-flight mass spectrum (SSJ/REMPI/TOF-MS) was measured for xylenols and ethylphenols. Sharp and intense peaks were observed in the REMPI spectrum of 2,4-xylenol, and the wavelength of the peak tentatively assigned to the 0-0 transition was the longest among xylenols and ethylphenols. These results suggest that 2,4-xylenol, designated as a Class II chemical substance in the Pollutant Release and Transfer Register (PRTR), can be measured sensitively and selectively even when numerous isomers are present in the sample. | Qi P, Wang J, Jin J, Su F, Chen J (2010)
2,4-Dimethylphenol imprinted polymers as a solid-phase extraction sorbent for class-selective extraction of phenolic compounds from environmental water.
Talanta 81, 1630-1635 [PubMed:20441950]
[show Abstract]
A molecularly imprinted polymer (MIP) was prepared using 2,4-dimethylphenol (2,4-DMP) as template. The synthesis is optimized by using three different porogens, chloroform, acetonitrile and toluene. The MIP was used as a class-selective sorbent in molecularly imprinted solid-phase extraction (MIP-SPE) for pre-concentration and determination of phenolic compounds from the environmental water. The difference in recognition selectivity of the polymer columns was observed in HPLC system. The variables affecting the extraction efficiency of MIP-SPE procedure were systematically investigated to facilitate the class-selective extraction of phenols from spiked water samples. The spiked aqueous solution was adjusted to pH 6.0 before being percolated through the MIP-SPE cartridge at the flow rate of 0.5mLmin(-1). After rinsing with dichloromethane, the bound phenolic compounds were desorbed with acetonitrile containing 5% aqueous ammonia. The developed MIP-SPE method was demonstrated to be applicable to the analysis of phenolic compounds in the environmental water. | Norwitz G, Keliher PN (1978)
Semimicro spectrophotometric determination of nitroglycerine in propellants by use of 2,4-xylenol.
Talanta 25, 521-523 [PubMed:18962311]
[show Abstract]
A semimicro spectrophotometric method using 2,4-xylenol is proposed for the determination of nitroglycerine in propellants. The propellant is extracted with methylene chloride, the extract is diluted, and a 10-ml aliquot is evaporated just to dryness. Then 2,4-xylenol reagent and 63% v/v sulphuric acid are added to hydrolyse the nitroglycerine to nitrate and form 6-nitro-2,4-xylenol which is steam-distilled in a Parnas-Wagner Kjeldahl distillation apparatus into a water-ammonia-isopropyl alcohol mixture. The absorbance of the yellow solution of the anion of the 6-nitro-2,4-xylenol is measured. The calibration curve is prepared from potassium nitrate and an empirical factor (5.50) is used to convert from nitrogen content to nitroglycerine (the theoretical factor is 5.40). The 2,4-xylenol should be added before the sulphuric acid in order to prevent interference from diphenylamine and ethyl centralite. The method is designed for the usual nitrocellulose double-base propellants containing 8-50% of nitroglycerine. | Barjau J, Schnakenburg G, Waldvogel SR (2011)
Diversity-oriented synthesis of polycyclic scaffolds by modification of an anodic product derived from 2,4-dimethylphenol.
Angewandte Chemie (International ed. in English) 50, 1415-1419 [PubMed:21290525] | Barjau J, Fleischhauer J, Schnakenburg G, Waldvogel SR (2011)
Installation of amine moieties into a polycyclic anodic product derived from 2,4-dimethylphenol.
Chemistry (Weinheim an der Bergstrasse, Germany) 17, 14785-14791 [PubMed:22113936]
[show Abstract]
When 2,4-dimethylphenol is anodically treated, a dehydrotetramer with four contiguous stereocentres is readily obtained on a multi-gram scale. The substitution of a 2,4-dimethyl-phenoxy fragment by several amines was demonstrated, and the best results were obtained with primary amines. Optically pure α-chiral aliphatic amines yield diastereomeric mixtures that can be separated in most cases. The basic amine causes a partial hemiketal-opening of the bisbenzofuran moiety leading to an equilibrium within an α,β-unsaturated cyclohexenone. This dynamic behaviour occurs on the time scale of NMR spectroscopy and is also found by X-ray analysis providing a consistent picture. | Tsukatani H, Okudaira H, Shitamichi O, Uchimura T, Imasaka T (2010)
Selective determination of 2,4-xylenol by gas chromatography/supersonic jet/resonance-enhanced multiphoton ionization/time-of-flight mass spectrometry.
Analytica chimica acta 682, 72-76 [PubMed:21056717]
[show Abstract]
Gas chromatography/supersonic jet/resonance-enhanced multiphoton ionization/time-of-flight mass spectrometry (GC/SSJ/REMPI/TOF-MS) was employed for isomer-selective determination of 2,4-xylenol in river and seawater samples. The sample containing 2,4-xylenol was measured using argon, rather than helium, as the GC carrier gas to cool the analyte molecule sufficiently. The instrumental detection limit (IDL) achieved at a flow rate of 1 mLmin(-1) was 14 pg. Although this value was comparable to the value (ca. 10 pg) obtained by gas chromatography/electron impact/quadrupole mass spectrometry (GC/EI/QMS). When the flow rate was increased to 8 mLmin(-1), interference from the 2,5-xylenol isomer was completely suppressed. The IDL was degraded to 83 or 160 pg at a flow rate of 5 or 8 mLmin(-1), respectively. The recovery of 2,4-xylenol from the river and the seawater samples was 85 and 93%, respectively. The time for analysis was only 10 min per one sample in GC/SSJ/REMPI/TOF-MS. These results suggest that GC/SSJ/REMPI/TOF-MS is useful for the selective measurement of 2,4-xylenol, which has been designated a Class I chemical substance in the Pollutant Release and Transfer Register (PRTR). | Chen YF, Chao H, Zhou NY (2014)
The catabolism of 2,4-xylenol and p-cresol share the enzymes for the oxidation of para-methyl group in Pseudomonas putida NCIMB 9866.
Applied microbiology and biotechnology 98, 1349-1356 [PubMed:23736872]
[show Abstract]
Pseudomonas putida NCIMB 9866 utilizes p-cresol or 2,4-xylenol as a sole carbon and energy source. Enzymes catalyzing the oxidation of the para-methyl group of p-cresol have been studied in detail. However, those responsible for the oxidation of the para-methyl group in 2,4-xylenol catabolism are still not reported. In this study, real-time quantitative PCR analysis indicated pchC- and pchF-encoded p-cresol methylhydroxylase (PCMH) and pchA-encoded p-hydroxybenzaldehyde dehydrogenase (PHBDD) in p-cresol catabolism were also likely involved in the catabolism of 2,4-xylenol. Enzyme activity assays and intermediate identification indicated that the PCMH and PHBDD catalyzed the oxidations of 2,4-xylenol to 4-hydroxy-3-methylbenzaldehyde and 4-hydroxy-3-methylbenzaldehyde to 4-hydroxy-3-methylbenzoic acid, respectively. Furthermore, the PCMH-encoding gene pchF was found to be necessary for the catabolism of 2,4-xylenol, whereas the PHBDD-encoding gene pchA was not essential for the catabolism by gene knockout and complementation. Analyses of the maximum specific growth rate (μ m) and specific activity of the gene-knockout strain to different intermediates revealed the presence of other enzyme(s) with PHBDD activity in strain 9866. However, PHBDD played a major role in the catabolism of 2,4-xylenol in contrast to the other enzyme(s). | Balachandran V, Murugan M, Nataraj A, Karnan M, Ilango G (2014)
Comparative vibrational spectroscopic studies, HOMO-LUMO, NBO analyses and thermodynamic functions of p-cresol and 2-methyl-p-cresol based on DFT calculations.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy 132, 538-549 [PubMed:24892532]
[show Abstract]
In the present study structural properties of p-cresol, and 2-methoxy-p-cresol have been studied by using B3LYP/cc-pvdz and B3PW91/cc-pvdz of Density Functional Theory (DFT) utilizing Becke three exchange functional and Lee Yang Paar correlation functional. The Fourier transform infrared and Fourier transform Raman spectra of title molecules were recorded (solid phase). Optimized geometry, harmonic vibrational frequencies and various thermodynamic parameters of the title compounds were calculated with B3LYP/cc-pvdz, and B3PW91/cc-pvdz basis sets. Non-linear optical (NLO) behavior of the p-cresol and 2-methoxy-p-cresol were investigated by determining of electric dipole moment, polarizability α, and hyperpolarizability β using the above mentioned basis sets. The molecular properties such as ionization potential, electronegativity, chemical potential, electrophilicity have been deduced from HOMO-LUMO analysis employing the same basis sets. A detailed interpretation of the infrared and Raman spectra of title molecules were reported. UV spectrum was measured in different solvent. The energy and oscillator strength are calculated by Time Dependant Density Functional Theory (TD-DFT) results. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The complete assignments were performed on the basis of the potential energy distribution (PED) of vibrational modes, calculated with scaled quantum mechanics (SQM) method. Finally the theoretical FT-IR, FT-Raman, and UV spectra of the title molecules have also been constructed. | Rogachev AD, Salakhutdinov NF (2015)
Chemical composition of Pinus sibirica (Pinaceae).
Chemistry & biodiversity 12, 1-53 [PubMed:25641836]
[show Abstract]
Siberian pine (Pinus sibirica), also known as Siberian cedar pine and Siberian cedar, is an important plant that has been long used as a source of natural compounds and materials (wood, needles, soft resin, turpentine, colophony). Its chemical composition has been studied well enough; however, to our surprise, no articles that compile the phytochemical data have been published so far. Presumably, this is due to the fact that most of the studies were published in journals difficult to access and not indexed by search systems. This review, for the first time, presents a systematic compilation of available data of secondary metabolites occurring in the needles, shoots, bark, wood, seeds, and oleoresin of Pinus sibirica. | Chao HJ, Chen YF, Fang T, Xu Y, Huang WE, Zhou NY (2016)
HipH Catalyzes the Hydroxylation of 4-Hydroxyisophthalate to Protocatechuate in 2,4-Xylenol Catabolism by Pseudomonas putida NCIMB 9866.
Applied and environmental microbiology 82, 724-731 [PubMed:26567311]
[show Abstract]
In addition to growing on p-cresol, Pseudomonas putida NCIMB 9866 is the only reported strain capable of aerobically growing on 2,4-xylenol, which is listed as a priority pollutant by the U.S. Environmental Protection Agency. Several enzymes involved in the oxidation of the para-methyl group, as well as the corresponding genes, have previously been reported. The enzyme catalyzing oxidation of the catabolic intermediate 4-hydroxyisophthalate to the ring cleavage substrate protocatechuate was also purified from strain NCIMB 9866, but its genetic determinant is still unavailable. In this study, the gene hipH, encoding 4-hydroxyisophthalate hydroxylase, from strain NCIMB 9866 was cloned by transposon mutagenesis. Purified recombinant HipH-His6 was found to be a dimer protein with a molecular mass of approximately 110 kDa. HipH-His6 catalyzed the hydroxylation of 4-hydroxyisophthalate to protocatechuate with a specific activity of 1.54 U mg(-1) and showed apparent Km values of 11.40 ± 3.05 μM for 4-hydroxyisophthalate with NADPH and 11.23 ± 2.43 μM with NADH and similar Km values for NADPH and NADH (64.31 ± 13.16 and 72.76 ± 12.06 μM, respectively). The identity of protocatechuate generated from 4-hydroxyisophthalate hydroxylation by HipH-His6 has also been confirmed by high-performance liquid chromatography and mass spectrometry. Gene transcriptional analysis, gene knockout, and complementation indicated that hipH is essential for 2,4-xylenol catabolism but not for p-cresol catabolism in this strain. This fills a gap in our understanding of the gene that encodes a critical step in 2,4-xylenol catabolism and also provides another example of biochemical and genetic diversity of microbial catabolism of structurally similar compounds. | Zhong C, He M, Liao H, Chen B, Wang C, Hu B (2016)
Polydimethylsiloxane/covalent triazine frameworks coated stir bar sorptive extraction coupled with high performance liquid chromatography-ultraviolet detection for the determination of phenols in environmental water samples.
Journal of chromatography. A 1441, 8-15 [PubMed:26961915]
[show Abstract]
In this work, covalent triazine frameworks (CTFs) were introduced in stir bar sorptive extraction (SBSE) and a novel polydimethylsiloxane(PDMS)/CTFs stir bar coating was prepared by sol-gel technique for the sorptive extraction of eight phenols (including phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p-chloro-m-cresol and 2,4-dichlorophenol, 2,4,6-trichlorophenol) from environmental water samples followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection. The prepared PDMS/CTFs coated stir bar showed good preparation reproducibility with the relative standard deviations (RSDs) ranging from 3.5 to 5.7% (n=7) in one batch, and from 3.7 to 9.3% (n=7) among different batches. Several parameters affecting SBSE of eight target phenols including extraction time, stirring rate, sample pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) were found to be in the range of 0.08-0.30 μg/L. The linear range was 0.25-500 μg/L for 2-nitrophenol, 0.5-500 μg/L for phenol, 2-chlorophenol, 4-nitrophenol as well as 2,4-dimethylphenol, and 1-500 μg/L for p-chloro-m-cresol, 2,4-dichlorophenol as well as 2,4,6-trichlorophenol, respectively. The intra-day relative standard deviations (RSDs) were in the range of 4.3-9.4% (n=7, c=2 μg/L) and the enrichment factors ranged from 64.9 to 145.6 fold (theoretical enrichment factor was 200-fold). Compared with commercial PDMS coated stir bar (Gerstel) and PEG coated stir bar (Gerstel), the prepared PDMS/CTFs stir bar showed better extraction efficiency for target phenol compounds. The proposed method was successfully applied to the analysis of phenols in environmental water samples and good relative recoveries were obtained with the spiking level at 2, 10, 50 μg/L, respectively. | Zhong W, Wang D, Wang Z (2018)
Distribution and potential ecological risk of 50 phenolic compounds in three rivers in Tianjin, China.
Environmental pollution (Barking, Essex : 1987) 235, 121-128 [PubMed:29276958]
[show Abstract]
Phenolic compounds widely exist in the surface water of many countries; however, few studies have simultaneously analyzed and evaluated broad-spectrum phenolic compounds in various components of the water environment. Therefore this study analyzed the distribution and potential ecological risk of 50 phenolic compounds in the surface water, sediment and suspended particulate matter of three important rivers in Tianjin, the main heavy industry city with high pollution in China. The qualitative results show that phenolic pollution existed extensively in the three rivers and the kinds of phenolic compounds in the water were relatively higher than in both sediment and suspended particulate matter. The quantitative results show that the phenolic pollution in the wet-season samples was serious than dry-season samples. Meanwhile, total concentrations of phenolic compounds in three components from the Dagu Drainage River (DDR) were all much higher than those in the Beitang Drainage River (BDR) and Yongdingxin River (YDXR). The highest total concentrations of phenolic compounds in three components all appeared in wet-season samples in DDR, and the highest total concentration was 1354 μg/L in surface water, 719 μg/kg dw in suspended particulate matter and 2937 μg/kg dw in sediment, respectively. The ecological risk of phenolic compounds in surface water was evaluated using the quotient method, and phenolic compounds with risk quotient (RQ) > 1 (RQ > 0.3 for YDXR) were identified as priority pollutants. Five kinds of phenolic compounds were identified as priority phenolic compounds in BDR, and the order of risk was 2-cresol > 2,4-xylenol > 2-sec-butylphenol > 2-naphthol > 3-cresol. Six kinds of phenolic compounds were identified as priority phenolic compounds in DDR, and the order of risk was 2-naphthol > p-chloro-m-xylenol > 4-cresol > 3-cresol > 2,4-xylenol > 2,3,6-Trimethylphenol. In YDXR, only phenol, 2-naphthol and 2,4-xylenol were identified as priority phenolic compounds. | Latos P, Culkin A, Barteczko N, Boncel S, Jurczyk S, Brown LC, Nockemann P, Chrobok A, Swadźba-Kwaśny M (2018)
Water-Tolerant Trifloaluminate Ionic Liquids: New and Unique Lewis Acidic Catalysts for the Synthesis of Chromane.
Frontiers in chemistry 6, 535 [PubMed:30483493]
[show Abstract]
The first example of triflometallate ionic liquids, named in analogy to chlorometallate ionic liquids, is reported. Trifloaluminate ionic liquids, synthesized from 1-alkyl-3-methylimidazolium triflates and aluminum triflate, were characterized by multinuclear NMR spectroscopy and FT-IR spectroscopy, revealing the existence of oligonuclear, multiply-charged trifloaluminate anions, with multiple bridging triflate modes. Acceptor numbers were determined to quantify their Lewis acidity, rendering trifloaluminate ionic liquids as medium-strength Lewis acids (AN = ca. 65). Used as acidic catalysts in the cycloaddition of 2,4-dimethylphenol and isoprene (molar ratio 2:1) to prepare chromane, trifloaluminate systems outperformed literature systems, showing high activity (conversions 94-99%, selectivities 80-89%) and at low loadings (0.2 mol%) at 35°C. Using these new systems as supported ionic liquid phase (SILP) on multi-walled carbon nanotubes (ionic liquid loading 16 wt%) delivered a recyclable catalytic system, with activity enhanced with respect to the homogenous regime. | Kariuki MW, Hassanali A, Ng'ang A MM (2019)
Structure-activity studies on analogues of 4-methylguaiacol, a cattle anal odour constituent repellent to the brown ear tick (Rhipicephalus appendiculatus).
Acta tropica 194, 78-81 [PubMed:30922799]
[show Abstract]
Previously, 4-methylguaiacol, a major constituent of cattle anal odour, was found to have a high repellency on Rhipicephalus appendiculatus. In the present study, 10 structural analogues of the phenol were tested for repellency against R. appendiculatus in order to assess the effects of (i) absence or presence of the 4-alkyl group of varying length, (ii) inclusion of a double bond in the 4-alkyl chain, (iii) linking the two phenolic oxygen in a methylenedioxy bridge, (iv) replacement of the OCH3 with CH3 and inclusion of another CH3 at position 6, and (v) presence of an additional OCH3 group at position 6. The analogues comprised of 2-methoxyphenol (guaiacol), 4-ethyl-2-methoxyphenol, 4-propyl-2-methoxyphenol, 4-allyl-2-methoxyphenol (eugenol), 3,4-methylenedioxytoluene, 2,4-dimethylphenol, 4-ethyl-2-methylphenol, 2,4,6-trimethylphenol, 4-propyl-2,6-dimethoxy-phenol and 4-allyl-2,6-dimethoxyphenol, which were compared at different concentrations in a two-choice climbing assay set up. Each analogue showed either increased or reduced repellency compared with 4- methylguaiacol. The structural feature that was associated with the highest repellency was 4-propyl moiety in the guaiacol unit (RD75 = 0.031 for 4-propyl-2-methoxyphenol; that of 4-methylguaiacol = 0.564). Effects of blending selected analogues with high repellency were also compared. However, none of the blends showed incremental increases in repellency compared with that of 4-propyl-2-methoxyphenol. We are currently evaluating the effects of controlled release of this compound at different sites on cattle on the behavior and success of R. appendiculatus to locate their predilection for feeding sites. | Malewschik T, de Serrano V, McGuire AH, Ghiladi RA (2019)
The multifunctional globin dehaloperoxidase strikes again: Simultaneous peroxidase and peroxygenase mechanisms in the oxidation of EPA pollutants.
Archives of biochemistry and biophysics 673, 108079 [PubMed:31445024]
[show Abstract]
The multifunctional catalytic hemoglobin dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata was found to catalyze the H2O2-dependent oxidation of EPA Priority Pollutants (4-Me-o-cresol, 4-Cl-m-cresol and pentachlorophenol) and EPA Toxic Substances Control Act compounds (o-, m-, p-cresol and 4-Cl-o-cresol). Biochemical assays (HPLC/LC-MS) indicated formation of multiple oxidation products, including the corresponding catechol, 2-methylbenzoquinone (2-MeBq), and oligomers with varying degrees of oxidation and/or dehalogenation. Using 4-Br-o-cresol as a representative substrate, labeling studies with 18O confirmed that the O-atom incorporated into the catechol was derived exclusively from H2O2, whereas the O-atom incorporated into 2-MeBq was from H2O, consistent with this single substrate being oxidized by both peroxygenase and peroxidase mechanisms, respectively. Stopped-flow UV-visible spectroscopic studies strongly implicate a role for Compound I in the peroxygenase mechanism leading to catechol formation, and for Compounds I and ES in the peroxidase mechanism that yields the 2-MeBq product. The X-ray crystal structures of DHP bound with 4-F-o-cresol (1.42 Å; PDB 6ONG), 4-Cl-o-cresol (1.50 Å; PDB 6ONK), 4-Br-o-cresol (1.70 Å; PDB 6ONX), 4-NO2-o-cresol (1.80 Å; PDB 6ONZ), o-cresol (1.60 Å; PDB 6OO1), p-cresol (2.10 Å; PDB 6OO6), 4-Me-o-cresol (1.35 Å; PDB 6ONR) and pentachlorophenol (1.80 Å; PDB 6OO8) revealed substrate binding sites in the distal pocket in close proximity to the heme cofactor, consistent with both oxidation mechanisms. The findings establish cresols as a new class of substrate for DHP, demonstrate that multiple oxidation mechanisms may exist for a given substrate, and provide further evidence that different substituents can serve as functional switches between the different activities performed by dehaloperoxidase. More broadly, the results demonstrate the complexities of marine pollution where both microbial and non-microbial systems may play significant roles in the biotransformations of EPA-classified pollutants, and further reinforces that heterocyclic compounds of anthropogenic origin should be considered as environmental stressors of infaunal organisms. | Maliang H, Wang P, Chen A, Liu H, Lin H, Ma J (2021)
Bamboo Tar as a Novel Fungicide: Its Chemical Components, Laboratory Evaluation, and Field Efficacy Against False Smut and Sheath Blight of Rice and Powdery Mildew and Fusarium Wilt of Cucumber.
Plant disease 105, 331-338 [PubMed:32772833]
[show Abstract]
The application of agricultural and forest residues can benefit the environment and the economy; however, they also generate a large amount of byproducts. In this study, bamboo tar (BT), a waste product of bamboo charcoal production, was dissolved in natural ethanol and the surfactant alkyl glucoside to manufacture a 50% (wt/wt) BT emulsifiable concentrate (BTEC) biopesticide. BTEC was screened for fungicidal activity against pathogens. The greatest activity was seen against Ustilaginoidea virens with a half-maximal effective concentration (EC50) value of 6 mg/liter. Four phytopathogenic fungi, Podosphaera xanthii, Rhizoctonia solani, Fusarium oxysporum, and Botrytis cinerea, showed EC50 values of <60 mg/liter. Greenhouse tests in vivo showed 2,000 mg/liter BTEC had a 78.4% protective effect against U. virens, and replicated treatments had an 80.6% protective effect. In addition, replicated 2-year field trials were conducted in two geographic locations with four plant diseases: false smut (U. virens), rice sheath blight (Thanatephorus cucumeris [Frank] Donk), cucumber powdery mildew (P. xanthii), and cucumber Fusarium wilt (F. oxysporum). Results showed that 1,000 to 2,000 mg/liter BTEC significantly inhibited these diseases. Gas chromatography-mass spectrometry analysis showed that the total phenolic mass fractions of two BT samples were 45.39 and 48.26%. Eleven components were detected, and their percentage content was as follows (from high to low): 2,6-dimethoxyphenol > 2- or 4-ethylphenol > 2- or 4-methylphenol > phenol > 4-ethylguaiacol > dimethoxyphenol > 4-methylguaiacol > 4-propenyl-2,6-dimethoxyphenol > 2,4-dimethylphenol. Some of the phenolic compounds identified from the tar might be fungicidally active components. BT is a biochar waste, which has potential as a biofungicide and has promise in organic agriculture. The value of this tar may not be because of any fundamental physical differences from other synthetic fungicides but rather caused by reduced production expenses and more efficient use of waste products. | Abu-Alsoud GF, Hawboldt KA, Bottaro CS (2020)
Assessment of cross-reactivity in a tailor-made molecularly imprinted polymer for phenolic compounds using four adsorption isotherm models.
Journal of chromatography. A 1629, 461463 [PubMed:32841770]
[show Abstract]
Cross-reactivity is an important feature of molecularly imprinted polymers (MIPs), and is central to successful use of a pseudo-template in molecular imprinting. The adsorption and cross-reactivity of a molecularly imprinted polymer (MIP) designed for recognition of phenols from water was assessed using four different isotherm models (Langmuir (LI), Freundlich (FI), Langmuir-Freundlich (L-FI), and Brunauer, Emmett, and Teller (BET)). The L-FI model succeeded in explaining the cross-reactivity behavior through the total number of binding sites, the affinity constants and heterogeneity indices of the small phenols (phenol (ph), 2-methylphenol (2-MP), 3-methylphenol (3-MP), 2-chlorophenol (2-CP), 2,4-dimethylphenol (DMP), 2,4-dichlorophenol (DCP), 4-chloro-3-methylphenol (CMP)) with evidence that the phenols compete for binding sites based on their hydrophobicity as well as π-π, π-σ and dipole-dipole intermolecular forces. The recognition of the large phenols (2,4,6-trichlorophenol (TCP), pentachlorophenol (PCP), 4-teroctylphenol (4-OP), 4-nonylphenol (4-NP), which have much higher binding affinities than the smaller phenolic compounds, was explained with the BET isotherm model that predicts that multiple layers adsorb to the adsorbed monolayer. The adsorption behavior with MIPs is also shown to be superior to corresponding non-imprinted polymers and applicability of MIPs for trace analysis is highlighted. | Ramos RL, Moreira VR, Lebron YAR, Santos AV, Santos LVS, Amaral MCS (2021)
Phenolic compounds seasonal occurrence and risk assessment in surface and treated waters in Minas Gerais-Brazil.
Environmental pollution (Barking, Essex : 1987) 268, 115782 [PubMed:33120340]
[show Abstract]
This study provided a monitoring of phenolic compounds occurrence in a river and in its treated water by a conventional water treatment plant (WTP) throughout a year-period, in Minas Gerais - Brazil. Furthermore, the environmental risk (hazard quotient - HQ), the human health risk (margin of exposure - MOE), and the cancer risk were calculated for the compounds. The results indicated that sixteen out of the seventeen investigated phenolic compounds were detected at some point during the sampling campaign. The most frequent compounds in the raw surface water were 2,3,4-trichlorophenol (234TCP), 2,4-dimethylphenol (24DMP), and 4-nitrophenol (4NP), whereas in treated water were 4NP and bisphenol A (BPA). In addition, the highest total concentration values were corelated to the months in which there was less precipitation, demonstrating that the presence of this micropollutants may be subject to seasonality. From the treated water results, it was not possible to state the efficiency of the conventional WTP in eliminating the phenols, since in some samples the phenolic compounds were totally removed and in others their increase or formation occurred. Regarding to the risk assessments, most of the evaluated compounds were considered highly toxic to some trophic level and posed a significant human health risk. Additionally, the risk reduction of phenolics using conventional WTP was low. The sixteen phenols contamination in surface and drinking waters appears to be subject to seasonality. Besides that, an alarming risk for environment and human health was identified. | Ogata N, Tagishi H, Tsuji M (2020)
Inhibition of Acetylcholinesterase by Wood Creosote and Simple Phenolic Compounds.
Chemical & pharmaceutical bulletin 68, 1193-1200 [PubMed:33268651]
[show Abstract]
Anisakiasis is common in countries where raw or incompletely cooked marine fish are consumed. Currently, effective therapeutic methods to treat anisakiasis are unavailable. A recent study found that wood creosote inactivates the movement of Anisakis species. Essential oil of Origanum compactum containing carvacrol and thymol, which are similar to the constituents of wood creosote, was reported to inactivate Anisakis by inhibiting its acetylcholinesterase. We examined whether wood creosote can also inhibit acetylcholinesterase. We examined the effect of components of wood creosote using the same experimental method. A computer simulation experiment (molecular docking) was also performed. Here, we demonstrate that wood creosote inactivated acetylcholinesterase in a dose-dependent manner with an IC50 of 0.25 mg/mL. Components of wood creosote were also tested individually: 5-methylguaiacol, p-cresol, guaiacol, o-cresol, 2,4-dimethylphenol, m-cresol, phenol and 4-methylguaiacol inactivated the enzyme with an IC50 of 14.0, 5.6, 17.0, 6.3, 3.9, 10.0, 15.2 and 27.2 mM, respectively. The mechanism of acetylcholinesterase inactivation was analyzed using a computer-based molecular docking simulation, which employed a three-dimensional structure of acetylcholinesterase and above phenolic compounds as docking ligands. The simulation indicated that the phenolic compounds bind to the active site of the enzyme, thereby competitively blocking entry of the substrate acetylcholine. These findings suggest that the mechanism for the inactivation of Anisakis movement by wood creosote is due to inhibition of acetylcholinesterase needed for motor neuron activity. | Zhou X, Zhou Q, Chen H, Wang J, Liu Z, Zheng R (2021)
Influence of dimethylphenol isomers on electrochemical degradation: Kinetics, intermediates, and DFT calculation.
The Science of the total environment 794, 148284 [PubMed:34214809]
[show Abstract]
Dimethylphenol isomers (DMP) pose a great threat to the environment, and the electrooxidation (EO) process proves to be an extraordinarily effective method to degrade DMP. However, the EO performance is affected by the molecular structure of DMP and the adopted experimental parameters. In this study, the effects of 2,4-DMP and 2,6-DMP on the working potential, limiting current density (Jlim), and pH were systematically analysed, with Ti-mesh plates used as the cathode and Ti/PbO2 as the anode. The peak potentials of 2,4-DMP and 2,6-DMP were determined to be 0.83 V and 0.77 V by cyclic voltammetry, with Jlim were 2.5 mA·cm-2 and 2.0 mA·cm-2, respectively. The whole process exhibited pseudo-first-order kinetics, and the kinetic constants (K) for the degradation of 2,4-DMP and 2,6-DMP were determined to be 0.0041 min-1 and 0.0150 min-1, respectively. Additionally, the optimal initial pH value for 2,4-DMP and 2,6-DMP was 5.0, where the highest hydroxyl (OH) radical density, as determined by the electron spin technique (ESR), was achieved at a higher current density. Comparatively, the OH radical density in the 2,6-DMP solution was lower than that in 2,4-DMP. In situ Fourier infrared (FT-IR) spectroscopy, GC-MS, and density functional theory (DFT) were employed to explore three possible degradation pathways. The main intermediates for 2,4-DMP degradation were determined to be quinone and ether, while that for 2,6-DMP degradation was quinone. According to the results of this study, the molecular structure (different methyl group positions on the benzene ring) has a great influence on the EO process. | Chapman PJ, Hopper DJ (1968)
The bacterial metabolism of 2,4-xylenol.
The Biochemical journal 110, 491-498 [PubMed:4387388]
[show Abstract]
1. Measurements of the rates of oxidation of various compounds by a fluorescent Pseudomonas indicated that metabolism of 2,4-xylenol was initiated by oxidation of the methyl group para to the hydroxyl group. 2. 4-Hydroxy-3-methylbenzoic acid was isolated as the product of oxidation of 2,4-xylenol by cells inhibited with alphaalpha'-bipyridyl. 3. 4-Hydroxyisophthalic acid accumulated at low oxygen concentrations when either 2,4-xylenol or 4-hydroxy-3-methylbenzoic acid was oxidized by cells grown with 2,4-xylenol. 4. When supplemented with NADH, but not with NADPH, cell extracts oxidized 4-hydroxy-3-methylbenzoic acid readily. 2-Hydroxy-5-methylbenzoic acid was not oxidized. 5. Both 4-hydroxyisophthalic acid and p-hydroxybenzoic acid were oxidized to beta-oxoadipic acid by cell extracts supplemented with either NADH or NADPH. 4,5-Dihydroxyisophthalic acid was not oxidized. 6. From measurements of oxygen consumed and carbon dioxide evolved it was concluded that protocatechuic acid is an intermediate in the conversion of 4-hydroxyisophthalic acid into beta-oxoadipic acid. | Agee CC, Engelhardt JA, Gabridge MG (1980)
Antimycoplasmal activity of dimethylphenols in a tracheal explant culture system.
Antimicrobial agents and chemotherapy 18, 243-248 [PubMed:6778378]
[show Abstract]
Mycoplasma pneumoniae induces pneumonia-like symptoms in hamsters and causes ciliostasis and cytonecrosis in hamster tracheal explants. 2,4-Dimethylphenol and, to a lesser extent, its 2,3-, 2,5-, and 2,6-dimethylphenol isomers protected tracheal explants from these changes after exposure to virulent M. pneumoniae strain PI 1428. The effect was concentration, time, and isomer dependent. At concentrations of 10(-9) M or greater, 2,4-dimethylphenol completely prevented the morphological (loss of ciliated cells) and biochemical (decreased dehydrogenase activity) changes normally observed after exposure to M. pneumoniae. Apparently, 2,4-dimethylphenol interfered with an early event in the infection process. Complete protection required that it be present during the first 2 h of exposure of the explants to the infecting mycoplasmas. These xylenols may prove to be useful tools for helping to define the mechanisms of pathogenesis in certain respiratory infections. | Kaka JS, Somani SM, Schaeffer DJ (1982)
Metabolism and distribution of 2,4-dimethylphenol in rat.
Ecotoxicology and environmental safety 6, 35-40 [PubMed:7067652] | Daniel FB, Robinson M, Olson GR, York RG, Condie LW (1993)
Ten and ninety-day toxicity studies of 2,4-dimethylphenol in Sprague-Dawley rats.
Drug and chemical toxicology 16, 351-368 [PubMed:8281889]
[show Abstract]
Male and female Sprague-Dawley rats received 2,4-dimethylphenol daily by gavage for 10 or 90 consecutive days. The 10-day acute study doses were 0, 60, 120, 600 and 1200 mg/kg; the 90-day subchronic study doses were 0, 60, 180 and 540 mg/kg. Corn oil was used as the vehicle. In the 10-day study, all the high dose animals died. At 600 mg/kg there was a significant increase in relative liver weight in females and several significant alterations in hematologic and clinical chemistry values in both sexes. Histopathological examination revealed changes associated with the forestomach in all dose groups. The 90-day study had numerous compound-related deaths at the 540 mg/kg level. In addition, the final body weight in high dose males and females was significantly less while absolute lung weights and relative liver weights in females, and relative brain, kidney and testes weights in males were also altered. Significant clinical chemistry findings in high dose animals (540 mg/kg) included reduced creatinine and increased cholesterol in both sexes, with increased triglycerides and decreased AST in males only. Histopathologic evaluation revealed hyperkeratosis and epithelial hyperplasia of the forestomach in males and females in the middle and high-dose groups. |
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