Phenol

Impacts of circadian rhythm and melatonin on the specific activities of immune and antioxidant enzymes of the Chinese mitten crab (Eriocheir sinensis).[Pubmed:30974217]

Fish Shellfish Immunol. 2019 Apr 8. pii: S1050-4648(19)30250-5.

Many physiological functions of crustaceans show a rhythmic change to adapt to daily environmental cycles. However, daily variation in the immune and antioxidant status and its possible correlation with circulatory melatonin levels during the daily cycle have not been reported in the Chinese mitten crab, Eriocheir sinensis. In this study, the specific activities of immune and antioxidant enzymes of E. sinensis during the 24h cycle and its relationship with injected doses of melatonin were evaluated. The results showed that the immune parameters in the hemolymph, such as total hemolymph count, alkaline phosphatase, lysozyme, acid phosphatase, and Phenol oxidase, exhibited bimodal patterns during the 24h cycle, these parameters were synchronized with the activity of antioxidant enzymes such as malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase, and catalase. However, there was only one peak in the muscle (during 1200-1600h) and gills (during 0400-0800h). The survival rate reached approximately 80% in 5 days when melatonin concentrations were lower than 0.05g/L, significantly decreasing as melatonin concentrations increased. Four hours after melatonin injection, MDA levels in the muscle and hemolymph were significantly lower than those in the control group. Eight hours after melatonin injection, SOD levels in the hemolymph were significantly higher than those in the control group. These findings highlight the importance of considering circadian regulation of innate immunity when comparing immune responses at fixed times.

Antimonite complexation with thiol and carboxyl/phenol groups of peat organic matter.[Pubmed:30973221]

Environ Sci Technol. 2019 Apr 11.

Peatlands and other wetlands with abundant natural organic matter (NOM) are important sinks for antimony (Sb). While formation of Sb(III) sulfide phases or Sb(III) binding to NOM are discussed to decrease Sb mobility, the exact binding mechanisms remain elusive. Here, we reacted increasing sulfide concentrations with purified model peat at pH 6, forming reduced organic sulfur species, and subsequently equilibrated the reaction products with 50 microM antimonite under anoxic conditions. Sulfur solid-phase speciation and the local binding environment of Sb were analyzed using X-ray absorption spectroscopy. We found that 85% of antimonite was sorbed by untreated peat. Sulfide-reacted peat increased sorption to 98%. Shell-by-shell fitting of Sb K-edge X-ray absorption fine structure spectra revealed Sb in untreated peat bound to carboxyl or Phenol groups with average Sb-carbon distances of ~2.90 A. With increasing content of reduced organic sulfur, Sb was progressively coordinated to S atoms at distances of ~2.45 A and Sb-carbon distances of ~3.33 A, suggesting increasing Sb-thiol binding. Iterative target factor analysis allowed exclusion of reduced inorganic Sb-sulfur phases with similar Sb-sulfur distances. In conclusion, even when free sulfide concentrations are too low for formation of Sb-sulfur precipitates, peat NOM can sequester Sb in anoxic, sulfur-enriched environments.

Evidence Based Efficacy of Selected Herbal Extracts Against Culex quinquefasciatus (Say) Larvae.[Pubmed:30972982]

Pak J Biol Sci. 2019 Jan;22(3):127-132.

BACKGROUND AND OBJECTIVE: Chemical insecticides have some limitations in vectors control such as the emergence of resistance in vector mosquitoes to conventional synthetic insecticides. It aimed to evaluate the larvicidal efficacy and phytochemical potential of Azadirachta indica, Cymbopogon citratus and Allium sativum L. against ulex quinquefasciatus fourth instar larvae. MATERIAL AND METHODS: The plants were screened and evaluated for their phytochemical composition and larvicidal effects on . quinquefasciatus larvae. RESULTS: The bioassay results showed that the effects were dependent on time and concentration of the extract used. Results showed the least lethal dose value for ethanolic extract of . citrates (72 h exposure) and the highest value for aqueous extract of A. indica (24 h exposure). Chi-square values were significant at p<0.05. Phytochemical analysis showed phytochemicals such as alkaloids, flavonoids, cardiac glycosides and resins in all the three plants. However, tannins were absent in A. indica and A. sativum, while balsam was only present in A. indica. Saponins, balsam and Phenols were not found in A. sativum. Phenols were also absent in . citratus. Terpenes, steroids and resins were absent A. indica. CONCLUSION: Findings of this study revealed that these herbal extracts constitute an effective eco-friendly approach for the control of . quinquefasciatus larvae.

Utilization of a Silicone Rubber Membrane for Passive Oxygen Supply in a Microbial Fuel Cell Treating Carbon and Nitrogen from Synthetic Coke-Oven Wastewater.[Pubmed:30972705]

Appl Biochem Biotechnol. 2019 Apr 10. pii: 10.1007/s12010-019-02994-3.

This study firstly introduced a silicone rubber membrane (SRM) into microbial fuel cell (MFC) for passive oxygen supply to simultaneously remove Phenol and nitrogen from synthetic coke-oven wastewater diluted with seawater. Passive oxygen transport with biofilm on the membrane was improved by ~ 18-fold in comparison with the one without a biofilm. In addition, although the oxygen supply was passive, nitrification accounted for 34% of those aeration conditions. It was also found that silicone rubber membrane can control NO2(-)-N and/or NO3(-)-N production. A dual-chamber MFC treating the synthetic coke-oven wastewater achieved a maximum power density of 54 mW m(-2) with a coulombic efficiency of 2.7%. We conclude that silicone rubber membrane is effective for sustainable coke-oven wastewater treatment in MFCs.

High-Tg, Low-Dielectric Epoxy Thermosets Derived from Methacrylate-Containing Polyimides.[Pubmed:30966063]

Polymers (Basel). 2017 Dec 25;10(1). pii: polym10010027.

Three methacrylate-containing polyimides (Px(-)MMA; x = 1(-)3) were prepared from the esterification of hydroxyl-containing polyimides (Px(-)OH; x = 1(-)3) with methacrylic anhydride. Px(-)MMA exhibits active ester linkages (Ph(-)O(-)C(=O)(-)) that can react with epoxy in the presence of 4-dimethylaminopyridine (DMAP), so Px(-)MMA acted as a curing agent for a dicyclopentadiene-Phenol epoxy (HP7200) to prepare epoxy thermosets (Px(-)MMA/HP7200; x = 1(-)3) thermosets. For property comparisons, P1(-)OH/HP7200 thermosets were also prepared. The reaction between active ester and epoxy results in an ester linkage, which is less polar than secondary alcohol resulting from the reaction between Phenolic OH and epoxy, so P1(-)MMA/HP7200 are more hydrophobic and exhibit better dielectric properties than P1(-)OH/HP7200. The double bond of methacrylate can cure at higher temperatures, leading to epoxy thermosets with a high-Tg and moderate-to-low dielectric properties.

Grafting of Hindered Phenol Groups onto Ethylene/alpha-Olefin Copolymer by Nitroxide Radical Coupling.[Pubmed:30965973]

Polymers (Basel). 2017 Dec 4;9(12). pii: polym9120670.

The covalent immobilization of hindered Phenol groups, with potential antioxidant activity, onto an ethylene/alpha-olefin (EOC) copolymer was carried out by the nitroxide radical coupling (NRC) reaction performed in the melt with a peroxide and the 3,5-di-tert-butyl-4-hydroxybenzoyl-2,2,6,6-tetramethylpiperidine-1-oxyl radical (BHB-T). Functionalized EOC (EOC-g-(BHB-T)) was exposed to photo- and thermo-oxidation. By comparison with some model compounds bearing the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) moiety or the hindered Phenol unit, it was observed that the grafted BHB-T could effectively help the stabilization of the polymer matrix both under photo- and thermo-oxidation. In addition, the immobilization of BHB-T can effectively increase the service life of the functionalized polymers when polymer films were put in contact with ethanol solution thus simulating a possible application of the modified polymer.

A pH-Indicating Colorimetric Tough Hydrogel Patch towards Applications in a Substrate for Smart Wound Dressings.[Pubmed:30965861]

Polymers (Basel). 2017 Oct 26;9(11). pii: polym9110558.

The physiological milieu of healthy skin is slightly acidic, with a pH value between 4 and 6, whereas for skin with chronic or infected wounds, the pH value is above 7.3. As testing pH value is an effective way to monitor the status of wounds, a novel smart hydrogel wound patch incorporating modified pH indicator dyes was developed in this study. Phenol red (PR), the dye molecule, was successfully modified with methacrylate (MA) to allow a copolymerization with the alginate/polyacrylamide (PAAm) hydrogel matrix. This covalent attachment prevented the dye from leaching out of the matrix. The prepared pH-responsive hydrogel patch exhibited a porous internal structure, excellent mechanical property, and high swelling ratio, as well as an appropriate water vapour transmission rate. Mechanical responses of alginate/P(AAm-MAPR) hydrogel patches under different calcium and water contents were also investigated to consider the case of exudate accumulation into hydrogels. Results showed that increased calcium amount and reduced water content significantly improved the Young's modulus and elongation at break of the hydrogels. These characteristics indicated the suitability of hydrogels as wound dressing materials. When pH increased, the color of the hydrogel patches underwent a transition from yellow (pH 5, 6 and 7) to orange (7.4 and 8), and finally to red (pH 9). This range of color change matches the clinically-meaningful pH range of chronic or infected wounds. Therefore, our developed hydrogels could be applied as promising wound dressing materials to monitor the wound healing process by a simple colorimetric display, thus providing a desirable substrate for printed electronics for smart wound dressing.

Mechanism of Base-Catalyzed Resorcinol-Formaldehyde and Phenol-Resorcinol-Formaldehyde Condensation Reactions: A Theoretical Study.[Pubmed:30965730]

Polymers (Basel). 2017 Sep 7;9(9). pii: polym9090426.

The base-catalyzed resorcinol-formaldehyde condensation reactions were theoretically investigated in this study by employing a quantum chemistry method. The condensation reaction includes two steps: (1) formation of the quinonemethide (QM) intermediate from hydroxymethylresorcinol; (2) Michael addition between the quinonemethide and resorcinol anion. The first step is the rate-determining step. Two mechanisms, unimolecular elimination of the conjugate base (E1cb) and water-aided elimination (WAE), were identified for the formation of QM. The hydroxymethylresorcinol anion produces neutral QM while the dianion produces a quinonemethide anion (QMA). The calculated potential energy barriers suggested that the QMA formation is much more favorable. Although resorcinol-formaldehyde and Phenol-formaldehyde condensations share a common mechanism, the former would be faster if the QMA participates in condensations. The potential energy barriers for formation of 2-QM, 4-QM, 6-QM, 2-QMA, and 4-QMA were calculated. The results show that the formations of 6-QM and 4-QMA have relatively lower energy barriers. This rationalized previous experimental observations that the 2,4-(2,6-) and 6,6'-(4,4'-) methylene linkages were dominant, whereas the 2,2'-linkage was almost absent. The resorcinol-Phenol-formaldehyde co-condensations were also calculated. The cold-setting characteristic of Phenol-resorcinol-formaldehyde co-condensed resin can be attributed to participation of resorcinol quinonemethides in condensations.

Foodborne and Waterborne Disease in Canada - 1980 Annual Summary.[Pubmed:30965518]

J Food Prot. 1987 May;50(5):420-428.

Data on foodborne disease in Canada in 1980 are compared with those for 1979. A total of 759 incidents, comprising 621 outbreaks and 138 single cases, caused illnesses in 7,122 persons in 1980. Compared with 1979, fewer incidents but more cases occurred. Salmonella , Staphylococcus aureus , Clostridium perfringens and Bacillus cereus caused most illnesses. The main Salmonella serovars involved were S. typhimurium , S. heidelberg and S. enteritidis . Campylobacter and Citrobacter infections were reported for the first time. Seven episodes of paralytic shellfish poisoning occurred, more than twice the number in 1979. There were also 53 incidents and 100 cases of chemical origin; rancid compounds, extraneous matter and metals were the main chemicals involved. Unusual chemical problems included turkey contaminated with calcium chloride brine, antimony deliberately added to a beverage to induce sickness, ammonia-soaked frozen potato puffs, chocolates contaminated with Phenol disinfectant and toluene in popcorn twists. There were nine deaths from salmonellosis, paralytic shellfish poisonings and hemolytic uremic syndrome. About 34% of incidents and 51% of cases were associated with meat and poultry. Vegetables, fruits, Chinese food, marine food and bakery products were also vehicles that contributed significantly to foodborne disease. Mishandling of food took place mainly in foodservice establishments (41.2% of incidents, 74.3% of cases), homes (15.8% of incidents, 6.0% of cases) and food processing establishments (10.1% of incidents, 8.7% of cases). Food processors were responsible for salmonellosis from turkey rolls (440 cases) and staphylococcal intoxication from cheese curds (62 cases) and many small outbreaks and single cases. Most incidents occurred in Ontario (43.9%) and British Columbia (21.7%), but on a 100,000 population basis, British Columbia recorded more incidents (6.2) than Nova Scotia and Yukon (both 4.5) and Ontario (3.9). Narrative reports of seven foodborne disease incidents are presented. Four incidents of waterborne disease were documented in 1980, the same number as in 1979. All were caused by bacterial agents, with Campylobacter and Salmonella responsible for most cases. Pseudomonas aeruginosa infected the skin of 10 persons in a whirlpool bath.

Two Pairs of Isomerically New Phenylpropanoidated Epicatechin Gallates with Neuroprotective Effects on H2O2-Injured SH-SY5Y Cells from Zijuan Green Tea and Their Changes in Fresh Tea Leaves Collected from Different Months and Final Product.[Pubmed:30969762]

J Agric Food Chem. 2019 Apr 10.

Zijuan tea (Camellia sinensis var. assamica), an anthocyanin-rich cultivar with purple leaves, is a kind of valuable material for manufacturing tea with unique color and flavor. In this paper, four new phenylpropanoid substituted epicatechin gallates (pECGs), Zijuanins A-D (1-4), were isolated from Zijuan green tea by different column chromatography. Their structures were identified by extensive high resolution mass spectroscopy (HR-MS), nuclear magnetic resonance (NMR), experimental and calculated circular dichroism (CD) spectroscopic analyses. Detection of the changes in fresh tea leaves collected from April to September and the final processed product by high performance liquid chromatography (HPLC) -HRMS suggested that production of compounds 1 and 2 may be enhanced by the processing procedure of Zijuan green tea. Additionally, 1-4 were proposed to be synthesized through interaction between the abundant secondary metabolite ECG and Phenolic acids from tea leaves by two key steps of Phenol-dienone tautomerism. 1 and 2 showed impressive activity in protecting SH-SY5Y cells against H2O2-induced damage at the concentration of 1.0 muM.

High throughput DNA extraction of legume root nodules for rhizobial metagenomics.[Pubmed:30969386]

AMB Express. 2019 Apr 10;9(1):47.

A novel combination of tissue homogenization, cell lysis, and DNA purification techniques was developed for isolating total DNA from whole legume root nodules on an automated robotic system. Silica dehydrated root nodules from soy bean, Glycine max cv. Tara, and mung bean, Vigna radiata cv. Crystal, were homogenized in 96-well plates and were enzymatically and chemically lysed before being loaded into the AutoGenprep 965 for automated Phenol-chloroform based DNA isolation. The resulting DNAs were of relatively high concentration, low fragmentation, and free of Phenolic and polysaccharide contaminants. In contrast to manual methods, this adaptation of the Autogen Prep automated DNA extraction instrument allows for 100's to 1000's of samples to be prepared in a fraction of the time and cost.

N-Heterocyclic Carbene Derived 3-Azabutadiene as a pi-Base in Classic and Frustrated Lewis Pair Chemistry.[Pubmed:30968983]

Chemistry. 2019 Apr 10.

N-Heterocyclic carbene (NHC) derived 3-azabutadienes 1 and 2 have been prepared by a single step reaction of the corresponding NHC with cyclohexyl isocyanide. Compound 1 features pi-basic, delocalized nucleophilic sites over the 3-azabutadiene moiety, thereby allowing for coordinating with small Lewis acids, such as AlCl3, GaCl3 and Me2SAuCl, to form diverse classic Lewis adducts 3-5. Combination of 1 with B(C6F5)3 or [Ph3C][B(C6F5)4] resulted single electron transfer and the resulting radical cation was detected by EPR. In addition, a frustrated Lewis pair comprised of the pi-basic 1 and BPh3 effects the splitting of the O-H bond of Phenol and the N-H bond of imidazole to give 7 and 8, respectively. An intrinsic bond orbital (IBO) analysis of the pathway leading to 8 showcases the transformation of the delocalized pi-electrons of 1 to a newly formed C-H localized sigma bond.

Identification of 3-(trifluoromethyl)phenol as the malodorous compound in a pollution incident in the water supply in Catalonia (N.E. Spain).[Pubmed:30968295]

Environ Sci Pollut Res Int. 2019 Apr 9. pii: 10.1007/s11356-019-04635-y.

A study of organic compounds that caused a serious taste and odor episode of water supply in two residential areas in Catalonia (N.E. Spain) was carried out. Sweet and paint/solvent odor were the main descriptors used by consumers. Some cases of sickness and nausea were also associated with drinking water consumption by the consumers. Closed-loop stripping analysis (CLSA) combined with sensory gas chromatography and gas chromatography mass spectrometry detection were used to study the problem. As a result, 3-(trifluoromethyl)Phenol (CAS number 98-17-9) was for the first time identified as a responsible of an odor incident in drinking water. Concentration levels of this compound were up to 17,000 ng/L in groundwater and up to 600 ng/L in distributed water. Odor threshold in water for 3-(trifluoromethyl)Phenol was determined as 13 ng/L (45 degrees C).

A scalable electrochemical dehydrogenative cross-coupling of P(O)H compounds with RSH/ROH.[Pubmed:30968096]

Chem Commun (Camb). 2019 Apr 10.

A practical, scalable electrochemical dehydrogenative cross-coupling of P(O)H compounds with thiols, Phenols and alcohols in both an undivided cell and a continuous-flow setup is disclosed. Its broad substrate scope (>50 examples), good functional-group tolerance and scalability (>10 g) show potential for practical synthesis. A preliminary mechanistic study suggests that the phosphorus radicals are involved in the catalytic cycle.

An extendable all-in-one injection twin derivatization LC-MS/MS strategy for the absolute quantification of multiple chemical-group-based submetabolomes.[Pubmed:30967192]

Anal Chim Acta. 2019 Jul 31;1063:99-109.

The ability of LC-MS/MS for high coverage metabolite analysis lags behind the requirements of global metabolomics. The introduction of chemical derivatizations could significantly extend the ability of LC-MS/MS with enhanced MS response and improved LC separation, which has been serving as a promising quantitative tool for metabolomic analysis. However, as one specific derivatization reagent usually targets to a certain moiety, only a single chemical-group-based submetabolome could be analyzed in one injection. Therefore, the coverage of detected metabolites by derivatization-based LC-MS/MS is largely limited. To overcome this technical obstacle of derivatization-based LC-MS and increase submetabolome coverage, we proposed an extendable all-in-one injection LC-MS/MS strategy. 5-dimethylamino-naphthalene-1-sulfonyl chloride (Dns-Cl)/5-diethylamino-naphthalene-1-sulfonyl chloride (Dens-Cl) and 5-dimethylamino-naphthalene-1-sulfonyl piperazine (Dns-PP)/5-diethylamino-naphthalene-1-sulfonyl piperazine (Dens-PP) were used as twins labeling reagents for amino/Phenol and carboxyl submetabolomes, respectively. "Series Mode" and "Parallel Mode" were proposed and investigated using eight representative standards with the consideration of interaction between different derivatization systems, time-consumption, and extendability. As a result, we found that "Series Mode" led to yield reduction, while "Parallel Mode" gave identical results with those of individual derivatization. Finally, a "Parallel Mode" was chosen to develop an extendable all-in-one injection twin derivatization LC-MS/MS strategy to quantify eighty metabolites assigned to five classes of microbial metabolites, including polyamines, amino acids, indole derivatives, bile acids, and free fatty acids. This well-validated method quantified 67 metabolites absolutely and discovered additional 40 differential metabolites compared with the untargeted method in rat serum from irinotecan (CPT-11)-induced gastrointestinal toxicity model.