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ABSTRACT Aromatoleum aromaticum EbN1T anaerobically degrades phenol, p-cresol, and p-ethylphenol, each via a distinct peripheral pathway. The compound-specific regulation of each pathway is proposed to occur on the transcriptional level in the case of phenol supposedly mediated by the one-component system PheR. To confirm its predicted function, we generated an unmarked, in-frame deletion mutant (ΔpheR). This mutant did not express the ppsA1 gene, which encodes the A1 subunit of phenol-activating phenylphosphate synthase. The expression of ppsA1 was restored by in trans complementation of pheR into the ΔpheR background. The responsiveness to phenol was studied in vivo in benzoate-limited anaerobic cultures by adding, upon benzoate depletion, single defined pulses of phenol (from 100 µM down to 0.1 nM). Time-resolved, targeted transcript profiling by qRT-PCR revealed a response threshold for ppsA1 expression of 30‒50 nM phenol. Notably, ppsA1 expression could not be induced by p-cresol or p-ethylphenol. Conversely, lack of expression was also observed for the additional target genes cmh (p-cresol degradation) and acsA1 (p-ethylphenol degradation) applying phenol or p-ethylphenol as well as phenol or p-cresol as stimuli. Thus, the sensory proteins PheR, PcrS, and EtpR should be highly selective for phenol, p-cresol, and p-ethylphenol, respectively. The implicated incapability of cross-stimulus binding was corroborated by comparing the predicted 3D structural models of the proteins’ sensory domains. While the ligand-binding pockets share the conserved hydroxy group-anchoring histidine and tryptophane, their distal faces in PcrS and EtpR are, compared to PheR, enlarged to accommodate the bulkier methyl (p-cresol) and ethyl group (p-ethylphenol), respectively. IMPORTANCE Aromatic compounds are globally abundant organic molecules with a multitude of natural and anthropogenic sources, underpinning the relevance of their biodegradation. A. aromaticum EbN1T is a well-studied environmental betaproteobacterium specialized on the anaerobic degradation of aromatic compounds. The here studied responsiveness toward phenol in conjunction with the apparent high ligand selectivity (non-promiscuity) of its PheR sensor and those of the related p-cresol (PcrS) and p-ethylphenol (EtpR) sensors are in accord with the substrate-specificity and biochemical distinctiveness of the associated degradation pathways. Furthermore, the present findings advance our general understanding of the substrate-specific regulation of the strain’s remarkable degradation network and of the concentration thresholds below which phenolic compounds become essentially undetectable and as a consequence should escape substantial biodegradation. Furthermore, the findings may inspire biomimetic sensor designs for detecting and quantifying phenolic contaminants in wastewater or environments.

2,6-di-tert-butylphenol (2,6-DTBP) ameliorates mechanical allodynia and thermal hyperalgesia produced by partial sciatic nerve ligation in mice, and selectively inhibits HCN1 channel gating. We hypothesized that the clinically utilized non-anesthetic dimerized congener of 2,6-DTBP, probucol (2,6-di-tert-butyl-4-[2-(3,5-di-tert-butyl-4-hydroxyphenyl)sulfanylpropan-2-ylsulfanyl]phenol), would relieve the neuropathic phenotype that results from peripheral nerve damage, and that the anti-hyperalgesic efficacy in vivo would correlate with HCN1 channel inhibition in vitro. A single oral dose of probucol (800 mg/kg) relieved mechanical allodynia and thermal hyperalgesia in a mouse spared-nerve injury neuropathic pain model. While the low aqueous solubility of probucol precluded assessment of its possible interaction with HCN1 channels, our results, in conjunction with recent data demonstrating that probucol reduces lipopolysaccharide-induced mechanical allodynia and thermal hyperalgesia, support the testing/development of probucol as a non-opioid, oral antihyperalgesic albeit one of unknown mechanistic action.

Alkylphenols are a kind of compounds produced by alkylation of phenolic compounds. Compared with other non-hydrocarbon compounds, alkylphenols are more soluble in water. In this paper, through three groups of oil-water distribution experiments at different temperatures (25 ℃, 45 ℃ and 65 ℃), different brine concentrations (4000 mg/L, 6000 mg/L and 8000 mg/L) and different crude oil types (X37, X45 and X61), the distribution characteristics of alkylphenols between oil and water were studied, and the variation law of alkylphenol distribution coefficient was determined. The results show that the oil-water partition coefficient increases with the increase of alkyl molecular weight of homologues; The oil-water partition coefficient of alkylphenols decreases with the increase of temperature, and alkyl homologues with higher molecular weights are more sensitive to temperature; The partition coefficient of alkylphenol in oil-water system increases with the increase of water salinity. According to the experimental results, temperature and salinity of water phase will cause the difference of oil-water partition coefficient of alkylphenol, and the influence of temperature is greater than that of salinity. The distribution behavior of alkylphenols between oil and water can provide more reference for the secondary migration of crude oil and the direction of water drive front in reservoir development.

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Background: This study evaluated the cardiopulmonary effects and anaesthetic depth induced by a propofol infusion rate of 0.8 mg/kg/min in monkeys (Sapajus apella). Materials and methods: Five capuchin monkeys received dextroketamine‐midazolam intramuscularly. After a maximum duration of 5 min, the values of the physiological parameters were recorded, and a venous catheter was placed. After recovery from chemical restraint, the animals were anaesthetized with propofol intravenously, which was maintained for 1 h. Physiological parameters, anaesthetic depth, the time and quality of anaesthetic recovery were evaluated. Results: Heart and respiratory rates, systolic blood pressure and rectal temperature during propofol infusion were lower than those during anaesthesia induction with dextroketamine‐midazolam. Unconsciousness, muscle relaxation and lack of response to tail clamping were observed during propofol infusion. No animals showed excitement or vocalization during anaesthetic recovery. Conclusion: Propofol infusion rate of 0.8 mg/kg/min promoted surgical general anaesthesia, with transient hypotension, which showed excellent anaesthetic recovery. [ABSTRACT FROM AUTHOR]

4-tert-Octylphenol (4-tOP) and triclosan (TCS) are endocrine disruptors which have been detected in environmental matrices such as air, soil and water at ultra-low levels. Exposure to endocrine disruptors may account at least in part, for the global increase in the incidence of non-communicable diseases like cancers and diabetes and may also lead to an imbalance in the aquatic ecosystem. River Buffalo is an important natural resource in the Eastern Cape of South Africa serving more than half a million people. The presence of the two compounds in the river water hitherto unknown was investigated during winter seasons using solid-phase extraction and gas chromatography–mass spectrometric techniques. The sampling points differed by some physicochemical parameters. The concentration of 4-tOP ranged 0–755 ng/L, median value 88.1 ng/L while that of TCS ranged 0–1264.2 ng/L and the median value was 82.1 ng/L. Hazard quotient as an index of exposure risk varied according to daphnids ˃ fish ˃ algae for 4-tOP exposure while HQ for TCS exposure was algae > daphnids = fish showing that both compounds were capable of causing imbalance in the aquatic ecosystem. [ABSTRACT FROM AUTHOR]

The bacterial catabolism of aromatic compounds has considerable promise to convert lignin depolymerization products to commercial chemicals. Alkylphenols are a key class of depolymerization products whose catabolism is not well-elucidated. We isolated Rhodococcus rhodochrous EP4 on 4-ethylphenol and applied genomic and transcriptomic approaches to elucidate alkylphenol catabolism in EP4 and Rhodococcus jostii RHA1. RNA-Seq and RT-qPCR revealed a pathway encoded by the aphABCDEFGHIQRS genes that degrades 4-ethylphenol via the meta-cleavage of 4-ethylcatechol. This process was initiated by a two-component alkylphenol hydroxylase, encoded by the aphAB genes, which were upregulated ~3,000-fold. Purified AphAB from EP4 had highest specific activity for 4-ethylphenol and 4-propylphenol (~2,000 U/mg) but did not detectably transform phenol. Nevertheless, a ΔaphA mutant in RHA1 grew on 4-ethylphenol by compensatory upregulation of phenol hydroxylase genes (pheA1-3). Deletion of aphC, encoding an extradiol dioxygenase, prevented growth on 4-alkylphenols but not phenol. Disruption of pcaL in the β-ketoadipate pathway prevented growth on phenol but not 4-alkylphenols. Thus, 4-alkylphenols are catabolized exclusively via meta-cleavage in rhodococci while phenol is subject to ortho-cleavage. A putative genomic island encoding aph genes was identified in EP4 and several other rhodococci. Overall, this study identifies a 4-alkylphenol pathway in rhodococci, demonstrates key enzymes involved, and presents evidence that the pathway is encoded in a genomic island. These advances are of particular importance for wide-ranging industrial applications of rhodococci, including upgrading of lignocellulose biomass.

This study presents de development and validation of an ultra- high performance liquid chromatography – tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of four parabens (methyl-, ethyl-, propyl-, and butyl-paraben (MeP, EtP, PrP, BuP), four bisphenols (BP) (BPA, BPB, BPF, and BPS) and two alkylphenols (nonyl phenol (NP) and tert-octylphenol (OP) in human placenta samples. After a short sample preparation time the extracts are analysed by UHPLC-MS/MS using negative electrospray ionization. Labeled internal standards and matrix-matched calibration are used for quantification of the compounds. The method was validated according FDA guideline for bio analytical methods using spiked samples at three concentration levels (0.5–5 and 25 ng g−1). The parameters accuracy and precision fulfill the criteria. Calibration curves are linear between 0.5 and 50 ng −1. The limits of detection and quantification are in the range of 0.1–0.3 ng g−1 and 0.2–0.7 ng g−1, respectively. The applicability of the method was demonstrated on 71 human placenta samples from a Belgian cohort. The detection frequency was highest for OP (95%), EtP (86%), BPA (49%) and BPS (44%). Among the quantified compounds the highest quantification frequency was observed for OP (85%), EtP (65%) and BPA (25%). The concentrations of parabens ranged from 0.5 to 7.1 ng g−1 for MeP, from 0.5 to 4.5 ng g−1 for EtP and from 0.5 to 9.1 ng g−1 for PrP. The levels of bisphenols ranged from 0.5 to 3.9 ng g−1 for BPA, from 0.6 to 2.1 ng g−1 for BPF and from 0.8 to 1.3 ng g−1 for BPS. BPB and NP were not detected and OP levels ranged from 0.5 to 3.7 ng g g−1. The results demonstrate that the developed analytical method is very sensitive and that levels of several compounds with known /suspected endocrine disrupting properties could be detected or quantified in human placenta samples. The results therefore suggest that fetal exposure to these compounds occurs. The method will be useful for studies to evaluate the health effects associated with this prenatal exposure. • Development of a new UHPLC-MS/MS method for endocrine disrupting compounds (EDC) in placenta • Sensitive method suited for epidemiological studies • Demonstrated presence of EDC in human placenta • Prenatal exposure to the studied compounds is suggested. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Background and purpose In models of neuropathic pain, inhibition of HCN1 is anti-hyperalgesic. 2,6-di- iso -propyl phenol (propofol) and its non-anesthetic congener, 2,6-di- tert -butyl phenol, inhibit HCN1 channels by stabilizing closed state(s). Experimental approach Using in vitro electrophysiology and kinetic modeling, we systematically explore the contribution of ligand architecture to alkylphenol-channel coupling. Key results When corrected for changes in hydrophobicity (and propensity for intra-membrane partitioning), the decrease in potency upon 1-position substitution (NCO∼OH >> SH >>> F) mirrors the ligands' H-bond acceptor (NCO > OH > SH >>> F) but not donor profile (OH > SH >>> NCO∼F). H-bond elimination (OH to F) corresponds to a ΔΔG of ∼4.5 kCal mol−1 loss of potency with little or no disruption of efficacy. Substitution of compact alkyl groups (iso -propyl, tert -butyl) with shorter (ethyl, methyl) or more extended (sec -butyl) adducts disrupts both potency and efficacy. Ring saturation (with the obligate loss of both planarity and π electrons) primarily disrupts efficacy. Conclusions and implications A hydrophobicity-independent decrement in potency at higher volumes suggests the alkylbenzene site has a volume of ≥800 Å3. Within this, a relatively static (with respect to ligand) H-bond donor contributes to initial binding with little involvement in generation of coupling energy. The influence of π electrons/ring planarity and alkyl adducts on efficacy reveals these aspects of the ligand present towards a face of the channel that undergoes structural changes during opening. The site's characteristics suggest it is "druggable"; introduction of other adducts on the ring may generate higher potency inverse agonists. [ABSTRACT FROM AUTHOR]

A fast methodology to quantify 4-tert-octylphenol (4-t-OP) and 4-nonylphenol (4-NP) and their mono- and di-ethoxylates was developed, validated, and applied to real wastewater samples. Dispersive liquid-liquid microextraction was employed as a sample preparation step, leading to a pre-concentration factor of roughly 30. Analysis was carried out by liquid chromatography-tandem mass spectrometry with electrospray ionisation in multiple reaction monitoring mode. Average recoveries were generally between 80 and 120% for both the alkylphenols and their mono- and di-ethoxylates in influent and effluent wastewater. A minimum of 5 concentration levels per compound, ranging between 1 and 500 ng/mL, were prepared to construct calibration curves making use of isotopically labelled internal standards. The method presented good linearity and repeatability over the whole range of concentrations. Taking into account the concentration factor, and the recovery of the compounds, lower limits of quantification obtained in effluent wastewater were 0.04 ng/mL for 4-t-OP and 0.14 ng/mL for 4-NP, complying with European regulations, and between 0.03 ng/mL and 0.39 ng/mL for the ethoxylates. In influent wastewater, these limits were slightly higher. The total run time of 5 min for the alkylphenols and 8 min for the ethoxylates ensured high throughput. The developed method was applied to determine 4-t-OP and 4-NP and their mono- and di-ethoxylates in wastewater from several tank truck cleaning companies, which was subjected to ozonation and/or biological treatment. It was demonstrated that ozonation was best applied after the biological treatment, since in this case, the biological treatment could degrade most of the biodegradable organic matter, after which ozone could react directly with the recalcitrant organic pollutants. In this case, the concentrations of the target compounds in the wastewater of the investigated company decreased below the legally allowed concentration of the European water legislation. [ABSTRACT FROM AUTHOR]

The continuous directional cleavage of lignin provides a sustainable pathway for the synthesis of high-value alkylphenol chemicals. Herein, a multifunctional Mo/Ga@ZSM-11 catalyst and self-supplying hydrogen system were developed, 92.31 % of liquid products yield and 73.52 % of alkylphenol selectivity were achieved, and a good cyclic stability was maintained. Characterization results proved that Ga doped in the lattice gap of ZSM-11, lattice distortion and charge redistribution process generated more Si-O(H)-Ga sites and oxygen vacancies (O V), which provided ideal anchoring sites for active Mo species through covalent bond formation and strong metal-carrier interaction. The retention of terminal oxygen species Mo O(H) and the emergence of electron rich Mo species were accompanied by the derivation of abundant Brønsted/Lewis acid sites (BAS/LAS) and O V. A series of model compound experiments and kinetic analysis proved that BAS promoted the activation of self-supplying hydrogen system and the rapid fracture of aliphatic C-O/C-C bonds under heat drive, while the presence of strong LAS and O V ensured the further fracture of side chain methyl group (C Ar -OCH 3) in phenolic intermediates. The design concept of multifunctional catalyst provides guidance for the continuous directional cracking of lignin to produce high-value chemicals. [Display omitted] • Alkylphenols were enriched by lignin continuous directed pyrolysis. • Ga3+ can replace Si4+ in the ZSM-11 lattice gap to produce Si-O(H)-Ga and O V. • Mo=O(H)/Si‐O(H)‐Ga and electron-rich Mo leads to form abundant BAS/LAS. • BAS can activate self-supplying hydrogen system and lignin aliphatic C-O bonds. • The existed strong LAS and O V favor the demethoxylation and alkylation processes. [ABSTRACT FROM AUTHOR]

Importance: Aromatic compounds are globally abundant organic molecules with a multitude of natural and anthropogenic sources, underpinning the relevance of their biodegradation. A. aromaticum EbN1 T is a well-studied environmental betaproteobacterium specialized on the anaerobic degradation of aromatic compounds. The here studied responsiveness toward phenol in conjunction with the apparent high ligand selectivity (non-promiscuity) of its PheR sensor and those of the related p -cresol (PcrS) and p -ethylphenol (EtpR) sensors are in accord with the substrate-specificity and biochemical distinctiveness of the associated degradation pathways. Furthermore, the present findings advance our general understanding of the substrate-specific regulation of the strain's remarkable degradation network and of the concentration thresholds below which phenolic compounds become essentially undetectable and as a consequence should escape substantial biodegradation. Furthermore, the findings may inspire biomimetic sensor designs for detecting and quantifying phenolic contaminants in wastewater or environments., Competing Interests: The authors declare no conflict of interest.

The present study reports an ultra high-performance liquid chromatography tandem mass spectrometry method for the simultaneous determination of six bisphenols (bisphenol A, bisphenol B and bisphenol F) and alkylphenols (4-nonylphenol, 4- n -nonylphenol and octylphenol) in hotpot seasoning. Samples were dispersed in n -hexane after addition of internal standards bisphenol A- d 4 and 4- n -nonylphenol- d 4 . Sample solutions were then centrifuged, and the supernatants purified using solid phase extraction with high polarity Carb/PSA composite fillers. Six target analytes were separated on a Waters ACQUITY BEH C18 column by gradient elution with methanol and 0.05% ammonium hydroxide in water as the mobile phase, and determined under multiple reactions monitoring mode. The limits of detection and quantitation, matrix effect, recovery and precision of the method were investigated. Results were linear in the concentration range 0.1–250 µg/L for all compounds of interest, with R 2  > 0.9950. Limits of detection were in the range 0.1–0.4 μg/kg, and limits of quantitation were between 0.5 μg/kg and 1.0 μg/kg. The mean recoveries for negative samples at three spiked concentrations were in the range 87.9%–102.4%, and the intra-day precision and inter-day precision were in the ranges 2.1–8.2% and 4.8–11.2%, respectively. This method is accurate and sensitive, and had good clean-up characteristics, which might apply to screening and quantitation of target bisphenols and alkylphenols in hotpot seasoning. [ABSTRACT FROM AUTHOR]

In this contribution we present the results of an integrated investigation of selected nitrogen- and oxygen-bearing compounds in Norwegian Central Graben crude oils. We first provide an interpretation framework built on hydrocarbon biomarkers, and then use this framework to relate polar compound geochemistry to the influences of source facies (Farsund versus Mandal Formations), maturity, migration and reservoir lithology. Oil maturity could be assessed using established changes in carbazole annelation (N 1 DBE 9 vs. 12 vs. 15 classes), as well as hydrocarbon biomarkers. 29Ts/(29Ts + NH) correlated best with the polar compound maturity data. Secondary migration fractionation appears nevertheless to have played a role, as seen by increased DBE 9 and 12 carbazole and benzocarbazole proportions and a loss of C 2-3 DBE 12 homologues within carbonate reservoirs as compared to intraformational Upper Jurassic siliciclastic reservoirs. Thus migration distances, pathways and wettability of carrier systems ostensibly play a significant role in carbazole distributions of the Central Graben oils, manifesting itself as apparent maturity retardation. In an attempt to eliminate the migration component from maturity assessment, we here present a novel ternary diagram including dibenzocarbazoles (N 1 DBE 15) and phenolic species (O 1 DBE 4 and 5) based on a single measurement using the FT-ICR-MS. However, the integration of such results into 3D-modelling software must be conducted to clarify source kitchen, migration pathways and distances. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we developed a solid state sensor typically used for sensing alkylphenols in an aqueous environment. The colorimetric detection of the analyte is based on Fe(III)-impregnated silica assay with a detection limit that lies in the range of 10−8 mol L−1. The chromic Fe(III)-impregnated silica strip provides an immediate color change signal from yellow to dark purple upon exposure to an aqueous media of an alkylphenol as indicated by the coloration measurements. The visible color change of the thin layer chromatography (TLC) strip was found to change from yellow to dark purple proportionally by increasing the alkylphenol concentration. Recognition of alkylphenol occurs via Fe(III)-phenol complex formation. The energy dispersive spectroscopic analysis was employed to describe the elemental composition of Fe(III)-impregnated silica strip. This Fe(III)-TLC-based platform holds potential for the recognition of different categories of phenols. The proposed assay has the advantage of facile fabrication, portability, easy operation, rapidity, low cost and simplicity over other detection methods, without the need for sophisticated instrumentation and trained personnel.Graphical abstract: Facile, highly sensitive, fast detection, and portable Fe(III)-impregnated TLC sensor strips for nonylphenol in aqueous media displaying a remarkable visible color change from yellow to dark purple depending on phenol concentration. [ABSTRACT FROM AUTHOR]

The presence of phenolic compounds in the aquatic environment has posed severe risks due to their toxicity. Among the phenolic families, nitro- and alkyl-phenolic compounds have been categorized as precedence contaminants by the United States Environmental Protection Agency (US EPA). Therefore, efficient treatment methods for wastewater containing nitro- and alkyl-phenolic compounds are urgently needed. Due to the advantages of creating reactive species and generating efficient degradation of hazardous contaminants in wastewater, advanced oxidation processes (AOPs) are well-known in the field of treating toxic contaminants. In this review paper, the recent directions in AOPs, catalysts, mechanisms, and kinetics of AOPs are comprehensively reviewed. Furthermore, the conclusion summarizes the research findings, future prospects, and opportunities for this study. The main direction of AOPs lies on the optimization of catalyst and operating parameters, with industrial applications remain as the main challenge. This review article is expected to present a summary and in-depth understanding of AOPs development; and thus, inspiring scientists to accelerate the evolution of AOPs in industrial applications. • Recent advances in AOPs for the treatment of nitro- and alkyl-phenolic compounds are reviewed. • Development of AOPs technologies, process improvement, and catalysts are comprehensively reviewed. • Reaction kinetics and mechanism are comprehensively gathered. • Future prospects, opportunities, and conclusions are comprehensively discussed. [ABSTRACT FROM AUTHOR]

Bar adsorptive microextraction combined with liquid desorption followed by high performance liquid chromatography with diode array detection (BAµE-LD/HPLC-DAD) is proposed for the determination of trace levels of five phenol compounds (3-nitrophenol, 4-nitrophenol, bisphenol-A, 4-n-octylphenol and 4-n-nonylphenol) in surface water matrices. By using a polystyrene-divinylbenzene copolymer (PS-DVB) sorbent phase, high selectivity and efficiency is achieved even against polydimethylsiloxane through stir bar sorptive extraction. Assays performed by BAµE(PS-DVB)-LD/HPLC-DAD on 25 mL water samples spiked at the 10.0 µg/L levels yielded recoveries over 88.0% ± 5.7% for all five analytes, under optimized experimental conditions. The analytical performance showed good precision (RSD < 15%), detection limits of 0.25 µg/L and linear dynamic ranges (1.0–25.0 μg/L) with determination coefficient higher than 0.9904. By using the standard addition method, the application of the present method to surface water matrices allowed very good performances at the trace level. The proposed methodology proved to be a suitable alternative to monitor phenol compounds in surface water matrices, showing to be easy to implement, reliable, sensitive and requiring a low sample volume.

The long-proposed use of open-cell polyurethane foam (PUF) as a convenient ‘solid-phase extractant’ for aqueous organic compounds has been hindered by a critical lack of understanding on the underlying specificity of its extraction mechanism. In this work, we tasked ourselves to understand the hierarchy of molecular structure, properties, and partitioning characteristics of compounds in PUF and aqueous phase by targeting lipophilic phenolic compounds (LPCs) as a group of primary targets for PUF extraction. Using six structurally related bisphenol analogs as comparative probes, we identified molecular lipophilicity and H-bond acidity as key molecular attributes that governed their extractability by PUF. Molecular modeling study on H-bonding interactions between PUF surrogates, bisphenols, and water molecules elucidated the governing effect of H-bond acidity in the binding affinity of guest molecules onto PUF lone-pair donors. A holistic view must be adopted when assessing the extractability of LPCs with reactive lone-pair donors e.g. bisphenol S which forms multidentate H-bond adducts with water molecules. We validated our theory on two model groups of monofunctional LPCs, alkylphenols and chlorophenols, with the observation that the presence of a second proton-donating moiety dramatically enhanced the extractability of bisphenol molecules. The specificity of PUF rendered it selective towards compounds with correlating molecular attributes against other structural analogs and co-existing matrix organics. For LPCs, the PUF macromolecular structure can be conceptualized as a flexible 'molecular zipper network' that is most affinitive towards nonionic, permeable, and lipophilic guest molecules with multiple reactive proton donors. [ABSTRACT FROM AUTHOR]

Selective oxidation of aliphatic C-H bonds in alkylphenols serves significant roles not only in generation of functionalized intermediates that can be used to synthesize diverse downstream chemical products, but also in biological degradation of these environmentally hazardous compounds. Chemo-, regio-, and stereoselectivity; controllability; and environmental impact represent the major challenges for chemical oxidation of alkylphenols. Here, we report the development of a unique chemomimetic biocatalytic system originated from the Gram-positive bacterium Corynebacterium glutamicum. The system consisting of CreHI (for installation of a phosphate directing/anchoring group), CreJEF/CreG/CreC (for oxidation of alkylphenols), and CreD (for directing/anchoring group offloading) is able to selectively oxidize the aliphatic C-H bonds of p- and m-alkylated phenols in a controllable manner. Moreover, the crystal structures of the central P450 biocatalyst CreJ in complex with two representative substrates provide significant structural insights into its substrate flexibility and reaction selectivity. [ABSTRACT FROM AUTHOR]

Over the last 30 years, the Geum River Estuary and Saemangeum Coast have been subject to major environmental changes, including dike construction, reclamation, and development of industrial complexes. This study aimed to: 1) investigate the occurrence of polycyclic aromatic hydrocarbons (PAHs), alkylphenols (APs), and styrene oligomers (SOs), 2) identify the sources of sedimentary organic matter, and 3) determine key environmental factors controlling the macrozoobenthos community structure. A total of 58 surface sediments were collected from the estuary and coastal area in 2014. Specific persistent organic contaminants (POCs), including 24 PAHs, 6 APs, and 10 SOs were measured. PAHs, APs, and SOs were detected in the sediments at all sites, with concentrations varying among sites. Although POCs concentrations were generally below the Canadian sediment quality guidelines, relatively greater concentrations of POCs were found at some sites adjacent to industrial complexes and the estuarine area. Sediment organic carbon, total nitrogen, and the stable carbon isotope ratio (δ 13 C) were determined. Some sites near watergate had about 2–3‰ lighter δ 13 C values compared to other areas, indicating that these sites are affected by terrestrial organic matter. The number of species in the macrofaunal community was significantly correlated with δ 13 C values ( p < 0.001), positively, suggesting that the origin of sedimentary organic matter is important for controlling the macrozoobenthos distribution. Overall, this research provides information about the level and sources of sediment pollution, the origins of organic matter, and the relationships with the macrofaunal community. [ABSTRACT FROM AUTHOR]

The compound m -cresol (meta -cresol) is an important representative of alkylphenol pollutants with high toxicity and potential carcinogenicity. The genes and enzymes associated with the m -cresol pathway have not yet been well elucidated. In this study, Comamonas thiooxydans CHJ601 was isolated from industrial wastewater and cultured utilizing m -cresol as the sole source of carbon and energy. m -Cresol catabolism begins with the oxidation of its methyl group in strain CHJ601. Genome sequencing and heterologous expression of key genes revealed its detailed catabolic pathway. m -Cresol methylhydroxylase (MchAB) catalyzed o -cresol (ortho -cresol), m -cresol, and p -cresol (para -cresol) in the presence of NADH and FAD. The K m value of m -cresol (48.74 ± 5.02 μM) for MchAB was much lower than that of o -cresol (747.80 ± 53.34 μM) and p -cresol (541.90 ± 41.43 μM). Molecular docking analysis showed that the binding affinities of MchAB against m -cresol with two hydrogen bonds are higher than p -cresol methylhydroxylase with one. The optimal substrate of MchAB was m -cresol, which can be catalyzed into 3-hydroxybenzyl alcohol and then oxidized to 3-hydroxybenzaldehyde. The mchC gene encoded 3-hydroxybenzaldehyde dehydrogenase, which catalyzes the oxidation of 3-hydroxybenzaldehyde to 3-hydroxybenzoate. The results indicated that MchAB and MchC are the first characterized enzymes to catalyze the oxidation of the meta -methyl group of m -cresol in the strain CHJ601. • An m -cresol-metabolizing Comamonas thiooxydans CHJ601 isolated from wastewater. • A novel m -cresol methylhydroxylase encoded by mchAB genes was characterized. • The meta -methyl oxidation studied here is differ from the reported para -oxidation. [ABSTRACT FROM AUTHOR]

2,6-di- tert -butylphenol (2,6-DTBP) ameliorates mechanical allodynia and thermal hyperalgesia produced by partial sciatic nerve ligation in mice, and selectively inhibits HCN1 channel gating. We hypothesized that the clinically utilized non-anesthetic dimerized congener of 2,6-DTBP, probucol (2,6-di- tert -butyl-4-[2-(3,5-di- tert -butyl-4-hydroxyphenyl)sulfanylpropan-2-ylsulfanyl]phenol), would relieve the neuropathic phenotype that results from peripheral nerve damage, and that the anti-hyperalgesic efficacy in vivo would correlate with HCN1 channel inhibition in vitro. A single oral dose of probucol (800 mg/kg) relieved mechanical allodynia and thermal hyperalgesia in a mouse spared-nerve injury neuropathic pain model. While the low aqueous solubility of probucol precluded assessment of its possible interaction with HCN1 channels, our results, in conjunction with recent data demonstrating that probucol reduces lipopolysaccharide-induced mechanical allodynia and thermal hyperalgesia, support the testing/development of probucol as a non-opioid, oral antihyperalgesic albeit one of unknown mechanistic action., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Peter A. Goldstein reports financial support was provided by US Department of Defense. Olaf A. Andersen reports financial support was provided by National Institutes of Health. Dianna E. Willis reports financial support was provided by National Institutes of Health. Peter A. Goldstein reports a relationship with Akelos, Inc. that includes: board membership and non-financial support. Gareth R. Tibbs reports a relationship with Akelos, Inc. that includes: board membership and non-financial support. Dianna E. Willis reports a relationship with Akelos, Inc. that includes: board membership and non-financial support. J. David Warren reports a relationship with Akelos, Inc. that includes: board membership and non-financial support. Peter A. Goldstein, Rebecca L. Joyce, and Gareth R. Tibbs are co-inventors on patents related to the development of alkylphenols for the treatment of neuropathic pain. J. David Warren, Dianna E. Willis, Gareth R. Tibbs, and Peter A. Goldstein serve on the Scientific Advisory Board for Akelos, Inc., a research-based biotechnology company that has secured a licensing agreement for the use of those patents., (© 2023 The Authors.)

The compound 3,5-xylenol is an essential precursor used in pesticides and industrial intermediate in the disinfectants and preservatives industry. Its widespread application makes it an important source of pollution. Microbial bioremediation is more environmentally friendly than the physicochemical treatment process for removing alkylphenols from a polluted environment. However, the 3,5-xylenol-degrading bacteria is unavailable, and its degradation mechanism remains unclear. Here, a 3,5-xylenol-metabolizing bacterial strain, designated Rhodococcus sp. CHJ602, was isolated using 3,5-xylenol as the sole source of carbon and energy from a wastewater treatment factory. Results showed that strain CHJ602 maintained a high 3,5-xylenol-degrading performance under the conditions of 30.15 °C and pH 7.37. The pathway involved in 3,5-xylenol degradation by strain CHJ602 must be induced by 3,5-xylenol. Based on the identification of intermediate metabolites and enzyme activities, this bacterium could oxidize 3,5-xylenol by a novel metabolic pathway. One methyl oxidation converted 3,5-xylenol to 3-hydroxymethyl-5-methylphenol, 3-hydroxy-5-methyl benzaldehyde, and 3-hydroxy-5-methylbenzoate. After that, another methyl oxidation is converted to 5-hydroxyisophthalicate, which is metabolized by the protocatechuate pathway. It is catalyzed by a series of enzymes in strain CHJ602. In addition, toxicity bioassay result indicates that 3,5-xylenol is toxic to zebrafish and Rhodococcus sp. CHJ602 could eliminate 3,5-xylenol in water to protect zebrafish from its toxicity. The results provide insights into the bioremediation of wastewater contaminated 3,5-xylenol. • A 3,5-xylenol-utilizing bacterial Rhodococcus sp. CHJ602 isolated from wastewater. • A novel 3,5-xylenol catabolism pathway in CHJ602 strain was characterized. • CHJ602 strain can eliminate the toxicity of 3, 5-xylenol from water. [ABSTRACT FROM AUTHOR]

Endocrine disrupting compounds (EDCs) have been widely reported as potential carcinogenic threats to the human population. The release of EDCs to environmental compartments, such as water, sediment, and biota, has been monitored extensively. Considering the typically low levels of EDC concentrations found in environmental samples and the complexity of biota matrices, the main challenge is with the extraction and cleanup of samples, as well as with finding a sensitive enough instrumentation system for analyte detection. This paper presents a review of recent trends in the analysis of EDCs in environmental matrices. The focus of this review is three classes of environmentally important EDCs; namely, pharmaceuticals, estrogenic hormones, and alkylphenol compounds. Discussions about state-of-the-art instrumentation and sample preparation techniques, as well as a review of sample storage and preservation, are highlighted. Overall, the use of LC-MS-MS as an instrumentation technique has increased over the past 15 years. [ABSTRACT FROM AUTHOR]

Stringent and periodic iteration of regulations related to the monitoring of chemical releases from the offshore oil and gas industry requires the use of ever changing, rapidly developing and technologically advancing techniques. Passive samplers play an important role in water column monitoring of produced water (PW) discharge to seawater under Norwegian regulation, where they are used to; i) measure aqueous concentrations of pollutants, ii) quantify the exposure of caged organisms and investigate PW dispersal, and iii) validate dispersal models. This article summarises current Norwegian water column monitoring practice and identifies research and methodological gaps for the use of passive samplers in monitoring. The main gaps are; i) the range of passive samplers used should be extended, ii) differences observed in absolute concentrations accumulated by passive samplers and organisms should be understood, and iii) the link between PW discharge concentrations and observed acute and sub-lethal ecotoxicological end points in organisms should be investigated. [ABSTRACT FROM AUTHOR]

4- tert -butylphenol (4- t -BP), an endocrine disrupting chemical, is widely distributed in natural bodies of water but is difficult to biodegrade. In this study, we focused on the transformation of 4- t -BP in photo-initiated degradation processes. The steady-state photolysis and laser flash photolysis (LFP) experiments were conducted in order to elucidate its degradation mechanism. Identification of products was performed using the GC–MS, LC-MS and theoretical calculation techniques. The oxidation pathway of 4- t -BP by hydroxyl radical (HO ) was also studied and H 2 O 2 was added to produce HO . 4- tert -butylcatechol and 4- tert -butylphenol dimer were produced in 4- t -BP direct photolysis. 4- tert -butylcatechol and hydroquinone were produced by the oxidation of HO . But the formation mechanism of 4- tert -butylcatechol in the two processes was different. The benzene ring was fractured in 4- t -BP oxidation process and 29% of TOC was degraded after 16 h irradiation. [ABSTRACT FROM AUTHOR]

A simple online headspace solid-phase microextraction (HS-SPME) coupled with the gas chromatography-mass spectrometry (GC-MS) method was developed for simultaneous determination of trace amounts of nine estrogenic odorant alkylphenols and chlorophenols and their derivatives in water samples. The extraction conditions of HS-SPME were optimized including fiber selection, extraction temperature, extraction time, and salt concentration. Results showed that divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was the most appropriate one among the three selected commercial fibers, and the optimal extraction temperature, time, and salt concentration were 70 °C, 30 min, and 0.25 g/mL, respectively. The developed method was validated and showed good linearity ( R > 0.989), low limit of detection (LOD, 0.002-0.5 μg/L), and excellent recoveries (76-126 %) with low relative standard deviation (RSD, 0.7-12.9 %). The developed method was finally applied to two surface water samples and some of these target compounds were detected. All these detected compounds were below their odor thresholds, except for 2,4,6-TCAS and 2,4,6-TBAS wherein their concentrations were near their odor thresholds. However, in the two surface water samples, these detected compounds contributed to a certain amount of estrogenicity, which seemed to suggest that more attention should be paid to the issue of estrogenicity rather than to the odor problem. [ABSTRACT FROM AUTHOR]

In the present study, a fungal strain isolated from the Antarctic soil was identified as Penicillium sp. CHY-2 based on its 5.8S rRNA gene sequence analysis. Furthermore, its biodegradation ability towards 13 different toxic compounds such as 4-butylphenol (4-BP), 4- sec-butylphenol (4-s-BP), 4- tert-butylphenol (4-t-BP), 4-nonylphenol (4-NP), 4- tert-octylphenol (4-t-OP), 4-chlorophenol (4-CP), phenol, bisphenol A (BPA), benzene, toluene, xylene, naphthalene, and phenanthrene at low (4°C) and medium (15°C) temperature conditions was evaluated using high pressure liquid chromatography. Among the 13 compounds, the strain CHY-2 effectively degraded the six compounds i.e., 4-BP, 4-s-BP, 4-t-BP, 4-NP, 4-CP, and phenol at 15°C within one week, and at 4°C within 3 weeks. Also CHY-2 effectively degraded the 4-t-OP at 15°C (70%), but not at 4°C (35%). Among different carbon sources tested, glucose was found to be the most suitable and the growth of CHY-2 at 4°C was slower than at 15°C. Addition of Tween 80 increased the growth and degradation ability of CHY-2 towards 4-BP at 4 and 15°C. The metabolites produced during the degradation of 4-BP were identified by gas chromatography-mass spectrometry. Also, bacteria present in the Antarctic soil were determined by denaturing gradient gel electrophoresis and the result showed the presence of Pseudomonas and Syntrophus groups of bacteria. [ABSTRACT FROM AUTHOR]

In this work, the thermo-responsive polymer PNIPAM tethered to Fe 3 O 4 @SiO 2 @MOF core-shell magnetic microspheres was first synthesized by a surface-selective post-synthetic strategy and underwent highly efficient magnetic solid-phase extraction (MSPE) of alkylphenols from aqueous samples. Alkylphenols, including 4- tert -octylphenol (OP) and 4- n -nonylphenol (NP), were selected as target compounds. The sample quantification was carried out using LC–MS/MS in multiple reaction monitor (MRM) mode. Under optimal working conditions, the developed method showed good linearity in the range of 5–1000 ng L −1 , a low limit of detection (1.5 ng L −1 ), and good repeatability (relative standard deviation, <8%, n = 5) for NP and OP. Owning to the hydrophilic/hydrophobic switchable properties of the nanocomposite, high recoveries (78.7–104.3%) of alkylphenols were obtained under different extraction conditions. The levels of OP and NP in environmental samples collected from local river, lake and pond waters were analyzed using the developed method. It was believed that the synthesized material with the thermo-responsive coating, large surface areas and magnetic properties should have great potential in the extraction and removal of alkylphenols from environmental samples. [ABSTRACT FROM AUTHOR]

4- n -Nonylphenol (NP) is one of the most toxic alkylphenols found in the environment. To evaluate the transcriptional effects of NP in the viviparous fish Poecilia vivipara , a hepatic transcriptome and qPCR analysis of genes were carried out. Guppies separated by sex were injected with two doses of NP (15 μg/g and 150 μg/g) or peanut oil (control). After 24 h, analysis of transcriptional level of Aryl Hydrocarbon Receptor (AhR), Estrogen Nuclear Receptor Alpha (ESR1), Pregnane X Receptor (PXR), Cytochromes P450 (CYP1A , CYP2K1 and CYP3A30), Glutathione S-transferase A3 and Mu 3 (GSTa3 and GSTMu3), SRY-Box Transcription Factor 9 (SOX9), Vitellogenin-1 (VIT), ATP Binding Cassette Subfamily C Member 1 (ABCC1), Multidrug Resistance-Associated Protein 2 (MRP2) and UDP Glucuronosyltransferase Family 1 Member A1 (UGT1A1) was evaluated. 205,046 transcripts were assembled and protein prediction resulted in 203,147 predicted peptides. In females, no significant changes were detected in the transcription of some phase I biotransformation and ABC transporter genes. AhR, PXR, GSTa3 and SOX9 genes where higher in the lower dose group (15 μg/g) compared to control. In male fish, no changes were observed in the transcript levels of the nuclear receptors, in endocrine disruption and phase I biotransformation genes. GSTa3 showed lower transcription in fish treated with both doses. ABCC1 was higher in guppies treated with the lower dose while MRP2 showed less transcripts. This short-term and low-dose exposure to NP caused changes that could serve as early indicators of deleterious processes. These results indicate P. vivipara as a good sentinel in biomonitoring programs. [Display omitted] • Transcriptional changes were higher in female guppies. • Differential GSTa3 transcription were observed between sex. • Poecilia vivipara is a suitable sentinel species for field biomonitoring studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cardanols and alkylresorcinols are isolated from S. jambos fruit. • Cardanols reduce TG content in OA-overloaded HepG2 cells. • Cardanols activate AMPK/PPAR α signaling in OA-overloaded HepG2 cells. • An enrichment method for alkylphenols from S. jambos fruit is established. • Characterization of alkylphenols is achieved with 1H NMR data analysis. The chemical characteristics and hypolipidemic effects of alkylphenols in the fruit of Syzygium jambos were investigated in this study. Three cardanols (1 – 3; 1 as a new compound) and three alkylresorcinols (4 – 6) were isolated and identified from S. jambos fruit. Cardanols 1 and 2 (10–40 μM) suppressed lipids accumulation and reduced triglyceride content in oleic acid-overloaded HepG2 cells via the activation of AMPK/PPARα signaling pathways. Furthermore, the biological distribution of cardanols after an oral intake in mice was investigated. Compound 2 was detected in mice plasma, feces, and adipose tissues after a single oral intake (80 mg/kg body weight). In addition, an alkylphenols-enriched S. jambos fruit extract containing two bioactive compounds (95.9 and 198.6 μg/mg of compounds 1 and 2 , respectively) was prepared. Findings from the current study highlight the potential usage of cardanols as well as S. jambos fruit for the management of dyslipidemia. [ABSTRACT FROM AUTHOR]