Hydroquinone

Combined application of biochar with urease and nitrification inhibitors have synergistic effects on mitigating CH4 emissions in rice field: A three-year study.[Pubmed:32653704]

Sci Total Environ. 2020 Jul 3;743:140500.

Biochar and inhibitors applications have been proposed for mitigating soil greenhouse gas emissions. However, how biochar, inhibitors and the combination of biochar and inhibitors affect CH4 emissions remains unclear in paddy soils. The objective of this study was to explore the effects of biochar application alone, and in combination with urease (Hydroquinone) and nitrification inhibitors (dicyandiamide) on CH4 emissions and yield-scaled CH4 emissions during three rice growing seasons in the Taihu Lake region (Suzhou and Jurong), China. In Suzhou, N fertilization rates of 120-280 kg N ha(-1) increased CH4 emissions compared to no N fertilization (Control) (P < 0.05), and the highest emission was observed at 240 kg N ha(-1), possibly due to the increase in rice-derived organic carbon (C) substrates for methanogens. Biochar amendment combined with N fertilization reduced CH4 emissions by 13.2-27.1% compared with optimal N (ON, Suzhou) and conventional N application (CN-J, Jurong) (P < 0.05). This was related to the reduction in soil dissolved organic C and the increase in soil redox potential. Addition of urease and nitrification inhibitor (ONI) decreased CH4 emissions by 15.7% compared with ON treatment. Combined application of biochar plus urease, nitrification and double inhibitors further decreased CH4 emissions by 22.2-51.0% compared with ON and CN-J treatment. ON resulted in the highest yield-scaled CH4 emissions, while combined application of biochar alone and in combination with the inhibitors decreased yield-scaled CH4 emissions by 12.7-54.9% compared with ON and CN-J treatment (P < 0.05). The lowest yield-scaled CH4 emissions were observed under combined application of 7.5 t ha(-1) biochar with both urease and nitrification inhibitors. These findings suggest that combined application of biochar and inhibitors could mitigate total CH4 and yield-scaled CH4 emissions in paddy fields in this region.

Novel Hydroquinone-Alumina Composites Stabilizing a Guest-Free Clathrate Structure: Applications in Gas Processing.[Pubmed:32634302]

ACS Appl Mater Interfaces. 2020 Jul 7.

Organic clathrates formed by Hydroquinone (HQ) and gases such as CO2 and CH4, are solid supramolecular host-guest compounds, in which the gaseous guest molecules are encaged in a host framework of HQ molecules. Not only are these inclusion compounds fascinating scientific curiosities, but they can also be used in practical applications such as gas separation. However the development and future use of clathrate-based processes will largely depend on the effectiveness of the reactive materials used. These materials should enable fast and selective enclathration, and have a large gas storage capacity. This article discusses the properties and performance of a new composite material able to form gas clathrates with Hydroquinone (HQ) deposited on alumina particles. Apart from the general characterization of the HQ-alumina composite, one of the most remarkable observations is the unexpected formation of a guest-free clathrate structure with long term stability (>2 years) inside the composite. Interestingly enough, in addition to a slight improvement in the enclathration kinetics of pure CO2 compared to powdered HQ, preferential capture of CO2 molecules is observed when the HQ-alumina composite is exposed to an equimolar CO2/CH4 gas mixture. In terms of gas capture selectivity toward CO2, the performance of this new composite exceeds that of pure HQ and HQ-silica composites developed in a previous study, opening up new opportunities for the design and use of these novel materials for gas separation.

Chitosan-templated bio-coloration of cotton fabrics via laccase-catalyzed polymerization of hydroquinone.[Pubmed:32625039]

Eng Life Sci. 2019 Jul 25;19(9):643-654.

There is an increasing interest in the development of enzymatic coloration of textile fabrics as an alternative to conventional textile dyeing processes, which is successful for dyeing protein fibers. However, unmodified cotton fabrics are difficult to be dyed through enzyme catalysis due to the lack of affinity of biosynthesized dyes to cotton fibers. In order to improve the enzyme-catalyzed dyeability of cotton fibers, chitosan was used to coat cotton fabrics as template. A novel and facile bio-coloration technique using laccase catalysis of Hydroquinone was developed to dye chitosan-templated cotton fabrics. The polymerization of Hydroquinone with the template of chitosan under the laccase catalysis was monitored by ultraviolet-vis spectrophotometer on the absorbance of reaction solution. A significant peak of UV-vis spectrum at 246 nm corresponding to large conjugated structures appeared and increased with increasing the duration of enzymatic catalysis. The effect of different treatment conditions on the laccase-catalyzed dyeing of cotton fabric was investigated to determine their optimal parameters of laccase-catalyzed coloration. Fourier-transform infrared spectroscopy spectra demonstrated the formation of H-bond and Schiff base reaction between chitosan and polymerized Hydroquinone. Scanning electron microscopy indicated that the surface of dyed cotton fiber was much rougher than that of the control sample. Moreover, X-ray photoelectron spectroscopy also revealed the existence of the chitosan/polymerized Hydroquinone complex and polymerized Hydroquinone on the dyed cotton fibers. This chitosan-templated approach offers possibility for biological dyeing coloration of cotton fabrics and other cellulosic materials.

A one-pot process for synthesis of mitomycin analogs catalyzed by laccase/lipase optimized by response surface methodology.[Pubmed:32624973]

Eng Life Sci. 2019 Sep 30;19(11):805-814.

To reach the excellent yield as well as environmental friendliness, an efficient one-pot process for the synthesis of 2-methyl-3-n-butylaminoyl-1,4-benzoquinone, a mitomycin-like compound by the domino reaction of 2-methyl-1,4-Hydroquinone and butylamine using laccase/lipase as co-catalysts, has been developed. In this present study, the process proposed here was further improved by optimizing the relevant factors using the response surface methodology based on Box-Benkhen Design. The optimum condition that afforded the highest yield (98%) of 2-methyl-3-n-butylaminoyl-1,4-benzoquinone was obtained as follows: molar ratio of amines to Hydroquinones 1.16:1, activity ratio of laccase to lipase 1.14:2, and reaction temperature 38.9 degrees C. The results obtained indicate that this process may be useful as a green alternative method for higher yield production of mitomycin analogs.

Continuous and Rapid Synthesis of UiO-67 by Electrochemical Methods for the Electrochemical Detection of Hydroquinone.[Pubmed:32623890]

Inorg Chem. 2020 Jul 6;59(13):8827-8835.

Continuous and rapid synthesis of UiO-67 under mild conditions has been achieved by electrochemical methods for the first time. In the reaction system, a zirconium sheet was utilized as electrodes and a metal source for the assembly of UiO-67. High-crystalline UiO-67 with a regular tetrahedral morphology of around 1 mum was obtained within 1.5 h under the optimized solvent composition, voltage, and temperature conditions. This electrochemical synthetic method of UiO-67 in our work overcomes the shortcomings of high temperature and pressure of a traditional solvothermal method, which proposes new ideas for the large-scale and rapid synthesis of UiO-67. The UiO-67 synthesized by an electrochemical method was prepared as a UiO-67-carbon paste electrode (CPE), which exhibited a linear response to Hydroquinone (HQ) in the range of 5-300 muM with a detection limit of 3.6 x 10(-9) M (S/N = 3), for the electrochemical detection of HQ. It was confirmed that UiO-67-CPE possessed excellent reusability and antiinterference ability for the detection of HQ, and its detection ability even did not change after standing for 3 months. We further tried to apply UiO-67-CPE to the practical determination of HQ in tap water and river water samples, and the results proved that the recovery rate is 97.9-104.7% in real samples.

Heterogeneous electro-Fenton using three-dimension NZVI-BC electrodes for degradation of neonicotinoid wastewater.[Pubmed:32622128]

Water Res. 2020 May 27;182:115975.

Neonicotinoids (NEOs), as the most widely used pesticides, pose a serious threat to water ecosystems, especially clothianidin (CLO). However, the degradation behavior of CLO, as a new type of persistent organic pollutant, is rarely studied in wastewater treatment. To bridge this gap, heterogeneous electro-Fenton system using three-dimension electrodes made of biochar-supported zero-valent iron nanoparticle hybrid material (NZVI-BC), abbreviated as 3D-ICE-EF system, is invented and initially applied in CLO wastewater degradation, without the addition of Fenton reagent. NZVI-BC in 3D-ICE-EF system can concentrate CLO on electrodes by excellent adsorption and effectively eliminate it to achieve self-cleaning effect. In addition, the deposition of iron mud (Fe(OH)3) and the circular utilization of Fe in Fenton system is effectively improved by the addition of Hydroquinone (HQ) in 3D-ICE-EF system. The pH applicable scope of Fenton system is extended to alkaline condition by the applications of NZVI-BC electrodes. The increase in the acidity of electrolyte is considered the primary reason of the high degradation efficiency of CLO in 3D-ICE-EF system at an initial pH of 9.0. The degradation performance of 3D-ICE-EF system tends to be promoted by the increase of current intensity and air flow rate. Seven plausible mechanisms of CLO degradation were identified in 3D-ICE-EF system. The ecotoxicity evaluation of degradation products indicated that CLO degradation in 3D-ICE-EF system exhibits a remarkable tendency to reduce toxicity levels.

A Dipeptide-Based Hierarchical Nanoarchitecture with Enhanced Catalytic Activity.[Pubmed:32618091]

Angew Chem Int Ed Engl. 2020 Jul 3.

Achieving synthetic architectures with simple structures and robust biomimetic catalytic activities remains a great challenge. Herein, we explore a facile supramolecular assembly approach to construct a dipeptide-based hierarchical nanoarchitecture with enhanced enzyme-like catalytic activity. In this nanoarchitecture, nanospheres are with chain-like arrangement through coordination-driven directional self-assembly. The reversible transformation of anisotropic nanochains to isotropic nanospheres switches biomimetic activity. Notably, such assembled nanoarchitecture exhibits high enzyme-like activity and remarkable long-term stability to promote Hydroquinone oxidation, superior to the natural counterpart. This work will pave the way to develop reversible and reusable supramolecular biocatalysts with ordered hierarchical structures for accelerating chemical transformations.

Decrease of intracellular ROS by arbutin is associated with apoptosis induction and downregulation of IL-1beta and TNF-alpha in LNCaP; prostate cancer.[Pubmed:32614483]

J Food Biochem. 2020 Jul 2:e13360.

Increased reactive oxygen species (ROS) along with inflammation are involved in the prostate cancer (PCa). Therefore, this study was conducted to investigate the molecular mechanisms that were affected by arbutin as an antioxidant on prostate cancer cell line; LNCap. The intracellular ROS measurement confirmed that arbutin significantly (p < .05) decreased the ROS levels in a dose-dependent manner. Detection of cell death profile established that 1,000 muM of arbutin could remarkably induced apoptosis (p < .05), while tert-butyl hydroperoxide (tBHP) as ROS inducer prompted necrosis. In addition, 1,000 microM of arbutin successfully decreased expressions of IL-1beta and TNF-alpha genes (p < .05). Furthermore, evaluation of the IL-1beta protein level showed that arbutin could significantly decrease this cytokine (p < .05). In summary, reduction of ROS along with increasing apoptosis and decreasing expression of pro-inflammatory genes following arbutin treatment can open new visions in the treatment of prostate cancer using complementary medicine. PRACTICAL APPLICATIONS: Nowadays, arbutin as a glycosylated Hydroquinone is available commercially in both natural and synthetic forms. Arbutin is of interest because of its skin-lightening effect, and used in cosmetic products for cutaneous hyperpigmentation. Arbutin inhibited tyrosinase in melanocytes competitively. Moreover, arbutin was able to attenuate oxidative stress and, its anti-inflammatory activities has been established. In addition, arbutin has represented useful activities for suppression of malignant melanoma development. In addition, arbutin exhibits several pharmacological effects, including antimicrobial, antihyperlipidemic, antihyperglycemic, and alpha amylase inhibitory effects. In this study, we showed its effect on prostate cancer in vitro. Therefore, it opens new insights in the complementary medicine that can maintain or improve human health.

Hydration and swelling: a theoretical investigation on the cooperativity effect of H-bonding interactions between p-hydroxy hydroxymethyl calix[4]/[5]arene and H2O by many-body interaction and density functional reactivity theory.[Pubmed:32613574]

J Mol Model. 2020 Jul 1;26(7):190.

In order to explore the nature of the hydration and swelling of superabsorbent resin, a theoretical investigation into the cooperativity effect of the H-bonding interactions in the hydrates of four model compounds that can be regarded as the units of Hydroquinone formaldehyde resin (HFR) (i.e., O-hydroxymethyl-1,4-dihydroxybenzene, methylene di-O-hydroxymethyl-1,4-dihydroxybenzene, p-hydroxy hydroxymethyl calix[4]arene and p-hydroxy hydroxymethyl calix[5]arene) was carried out by many-body interaction and density functional reactivity theory. The HFR...H2O...H2O complexes, in which the H2O...H2O moieties are bound with both the hydroxyl groups of HFR, are the most stable. For the HFR(H2O)n clusters, the interaction energy per building block is increased as the number of the size n increases, indicating the cooperativity effect. Therefore, a deduction is given that the cooperativity effects of the H-bonding interactions play an important role in the process of the hydration and swelling of HFR, and the swelling behavior is mainly attributed to the cooperativity effects which arised from the interactions between the H2O molecules. The origin of the cooperativity effect was examined employing several information-theoretic quantities in the density functional reactivity theory. The degree of swelling of HFR was quantitated using a measure of volume. Graphical abstract.

Total Synthesis of (+/-)-Liphagal via Organic-Redox-Driven Palladium-Catalyzed Hydroxybenzofuran Formation.[Pubmed:32597646]

J Org Chem. 2020 Jun 29.

A synthetic route to liphagal, a natural PI3Kalpha inhibitor isolated from Aka coralliphaga, was established. The present route features an organic redox process where an alkynylquinone undergoes reductive cyclization in the presence of a Hydroquinone derivative such as hydroxyquinol (1,2,4-benzenetriol) and catalytic PdCl2 to provide a substituted benzofuran suitable for accessing the natural product. The benzofuran formation takes place via the redox transformation between the alkynylquinone and the electron-rich Hydroquinones followed by the concomitant Pd(II)-catalyzed oxycyclization of the resultant alkynylHydroquinone.

Clinical evaluation of efficacy, safety and tolerability of cysteamine 5% cream in comparison with modified Kligman's formula in subjects with epidermal melasma: A randomized, double-blind clinical trial study.[Pubmed:32585079]

Skin Res Technol. 2020 Jun 25.

BACKGROUND: Kligman's formula (KF) remains to date the dermatologists' treatment of choice for melasma. This study was aimed at the evaluation of the effectiveness of Modified Kligman's formula (MKF) in comparison with cysteamine 5% cream on the severity of epidermal melasma. MATERIALS AND METHODS: A total of 50 subjects with epidermal melasma were included in this double-blind, randomized trial study. Subjects received either cysteamine 5% cream or an MKF (4% Hydroquinone, 0.05% retinoic acid and 0.1% betamethasone). Cysteamine cream (applied once daily, 15 minutes exposure) or MKF (applied once daily, whole night exposure) were used by the subjects over four consecutive months. The efficacy of the treatments was determined through the modified Melasma Area Severity Index (mMASI) score, the Investigator's Global Assessment (IGA) and patient questionnaires. RESULTS: The mean (SD) age of the subjects was 34.96 (6.17) and 35.76 (5.23) years for cysteamine and MKF group, respectively. The mean mMASI score after 4 months was 7.04 (2.23) in the MKF group and 6.09 (2.01) in the cysteamine group. At both prospective evaluation points (2 months, 4 months), the percentage reduction in mMASI score was approximately 9% greater by cysteamine cream as compared to MKF, and these differences were statistically significant (P = .005 and .001 respectively). CONCLUSION: Cysteamine 5% cream showed greater efficacy as compared to MKF. It is thus proposed that cysteamine 5% cream is more effective than MKF in the treatment of melasma, with the advantage of being significantly better tolerated.

Discovery of Isoplumbagin as a Novel NQO1 Substrate and Anti-Cancer Quinone.[Pubmed:32575541]

Int J Mol Sci. 2020 Jun 19;21(12). pii: ijms21124378.

Isoplumbagin (5-hydroxy-3-methyl-1,4-naphthoquinone), a naturally occurring quinone from Lawsonia inermis and Plumbago europaea, has been reported to have anti-inflammatory and antimicrobial activity. Inflammation has long been implicated in cancer progression. In this study, we examined the anticancer effect of chemically synthesized isoplumbagin. Our results revealed that isoplumbagin treatment suppressed cell viability and invasion of highly invasive oral squamous cell carcinoma (OSCC) OC3-IV2 cells, glioblastoma U87 cells, non-small cell lung carcinoma H1299 cells, prostate cancer PC3 cells, and cervical cancer HeLa cells by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Boyden chamber assays. In vivo studies demonstrate the inhibitory effect of 2 mg/kg isoplumbagin on the growth of orthotopic xenograft tumors derived from OSCC cells. Mechanistically, isoplumbagin exerts its cytotoxic effect through acting as a substrate of reduced nicotinamide adenine dinucleotide phosphate [NAD(P)H] dehydrogenase quinone 1 (NQO1) to generate Hydroquinone, which reverses mitochondrial fission phenotype, reduces mitochondrial complex IV activity, and thus compromises mitochondrial function. Collectively, this work reveals an anticancer activity of isoplumbagin mainly through modulating mitochondrial dynamics and function.

Effect of quinoid redox mediators during azo dye decolorization by anaerobic sludge: Considering the catalyzing mechanism and the methane production.[Pubmed:32574861]

Ecotoxicol Environ Saf. 2020 Jun 20;202:110859.

The effects of quinoid compounds on azo dyes decolorization were studied. Compared with other quinones, menadione was the most effective at aiding azo dye decolorization. Sodium formate was a suitable carbon source for the anaerobic decolorization system. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis indicated that the microbial structure changed in response to varying carbon sources. Phylogenetic analysis showed that the anaerobic sludge was consisted mainly of nine genera. The mechanism studies showed that the biotransformation of menadione to its Hydroquinone form was the rate-limiting step in the dye decolorization process. Moreover, study of the electron transfer mechanism of quinone-mediated reduction showed that azo dye decolorization is not a specific reaction. The NADH chain was involved in the decolorization process. The methane production test indicated that azo dyes had an inhibitory effect on methane production. However, supplementation with a redox mediator could recover the inhibited methanogenesis. High-throughput sequencing analysis revealed that the methanogenic archaeal community was altered in the anaerobic sludge with or without azo dyes and the redox mediator.