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Tamara L Coletti Zabala, María E Zerbatto, Elda B R Perotti, Ana M Smacchia, Adriana Ombrella, Alejandro R Pidello
This work demonstrates that the addition of metronidazole together with a ubiquitous quinone compound reduces adherence of Lactobacillus acidophilus to ovine vaginal cells. Spectrophotometric and voltammetric studies have shown that neoformed compounds were observed in these systems; there were also changes in their electroactive composition, and the oxidant status had a significantly higher value compared to the control (p<0.05). Based on reduction potential (E; mV), the distribution of electroactive compound concentrations suggests that the compounds with low reduction potential induce this behavior, which would indicate that the addition of metronidazole with a ubiquitous quinone compound to the vaginal system might increase the reductive capacity of these systems...
December 2, 2016: Revista Argentina de Microbiología
Lillian C Becker, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen, Daniel C Liebler, James G Marks, Ronald C Shank, Thomas J Slaga, Paul W Snyder, F Alan Andersen
Cosmetic ingredients derived from Achillea millefolium function in cosmetics as skin-conditioning agents-miscellaneous, skin-conditioning agents-humectants, and fragrance ingredients. The Cosmetic Ingredient Review Expert Panel (Panel) reviewed relevant animal and human data to determine their safety in cosmetics and raised concerns about cosmetics containing linalool, thujone, quercetin, hydroquinone, or α-peroxyachifolid. Because final product formulations may contain multiple botanicals, each containing similar constituents of concern, formulators are advised to be aware of these components and to avoid reaching levels that may be hazardous to consumers...
November 2016: International Journal of Toxicology
Dong Ryun Gu, Joon No Lee, Gi-Su Oh, Hyung Jin Kim, Min Seuk Kim, Seoung Hoon Lee
β-lapachone (β-L) is a substrate of reduced nicotinamide adenine dinucleotide (NADH): quinone oxidoreductase 1 (NQO1). NQO1 reduces quinones to hydroquinones using NADH as an electron donor and consequently increases the intracellular NAD+/NADH ratio. The activation of NQO1 by β-L has beneficial effects on several metabolic syndromes, such as obesity, hypertension, and renal injury. However, the effect of β-L on bone metabolism remains unclear. Here, we show that β-L might be a potent inhibitor of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis...
November 30, 2016: Biochemical and Biophysical Research Communications
Shahla Khosravan, Ali Alami, Hossein Mohammadzadeh-Moghadam, Vahide Ramezani
Melasma disfigures the skin and thus influences people's self-image and self-concept. Therefore, melasma influences emotional and psychosocial health in addition to physical health. This clinical trial was performed to assess the effect of the topical use of Petroselinum crispum (parsley) on reduction of the severity of epidermal melasma.
January 2017: Holistic Nursing Practice
María Pedrero, F Javier Manuel de Villena, Cristina Muñoz-San Martín, Susana Campuzano, María Garranzo-Asensio, Rodrigo Barderas, José M Pingarrón
An amperometric magnetoimmunosensor for the determination of human p53 protein is described in this work using a sandwich configuration involving the covalent immobilization of a specific capture antibody onto activated carboxylic-modified magnetic beads (HOOC-MBs) and incubation of the modified MBs with a mixture of the target protein and horseradish peroxidase-labeled antibody (HRP-anti-p53). The resulting modified MBs are captured by a magnet placed under the surface of a disposable carbon screen-printed electrode (SPCE) and the amperometric responses are measured at -0...
November 21, 2016: Biosensors
Fanny Galimany-Rovira, Montse Miñarro-Carmona, Pilar Pérez-Lozano, Encarna García-Montoya, Josep R Ticó-Grau, Josep M Suñé-Negre
A previously published HPLC method for the simultaneous determination of six major components (hydroquinone, kojic acid, octinoxate, avobenzone, butylated hydroxyanisole, and butylated hydroxytoluene) in a skin-whitening cream was transferred and optimized to an ultra-performance LC system. Separation was achieved in a ZORBAX SB-Phenyl Rapid-Resolution High Throughput column (2.1 × 100 mm, 1.8 μm), using a mobile phase consisting of water with 0.1% acetic acid and acetonitrile at a flow rate of 0.7 mL/min...
September 29, 2016: Journal of AOAC International
Chelsea Ledford, Monica McMahon, Ashley Whitesell, Ghalib Khan, Suneel K Kandagatla, Dow P Hurst, Patricia H Reggio, Gregory M Raner
OBJECTIVE: To develop a model for binding and catalysis associated with the stimulation of 4-fluorophenol (4-FP) oxidation in the presence of long chain aldehydes by the enzymatic catalyst, cytochrome P450BM3-F87G. RESULTS: A variation of the Michaeli-Menten kinetic model was employed to describe interactions at the active site of the enzyme, along with computer aided modeling approaches. In addition to the hydroquinone product arising from de-fluorination of 4-FP, a second product (p-fluorocatechol) was also observed and, like the hydroquinone, its rate of formation increased in the presence of the aldehyde...
November 18, 2016: Biotechnology Letters
Jean-Philippe Gagné, Sophie Lachapelle, Chantal Garand, Serges P Tsofack, Yan Coulombe, Marie-Christine Caron, Guy G Poirier, Jean-Yves Masson, Michel Lebel
Werner syndrome (WS) is characterized by the premature onset of several age-associated pathologies including cancer. The protein defective in WS patients (WRN) is a helicase/exonuclease involved in DNA replication and repair. Here, we present the results of a large-scale proteome analysis that has been undertaken to determine protein partners of different polymorphic WRN proteins found with relatively high prevalence in the human population. We expressed different fluorescently tagged-WRN (eYFP-WRN) variants in human 293 embryonic kidney cells (HEK293) and used a combination of affinity-purification and mass spectrometry to identify different compositions of WRN-associated protein complexes...
November 14, 2016: Oncotarget
J Rodriguez, A García, T Poznyak, I Chairez
The aim of this study was to characterize the ozone reaction with phenanthrene adsorbed in two types of soils (sand and agricultural). The effect of soil physicochemical properties (texture, bulk density, particle density, porosity, elemental composition, permeability, surface area and pore volume) on the phenanthrene decomposition was evaluated. Commercial sand has a uniform morphology (spherical) with a particle size range between 0.178 and 0.150 mm in diameter, regular elemental composition SiO2, specific density of 1701...
November 14, 2016: Chemosphere
Emma K T Benn, Andrew Alexis, Nihal Mohamed, Yan-Hong Wang, Ikhlas A Khan, Bian Liu
Skin-bleaching practices, such as using skin creams and soaps to achieve a lighter skin tone, are common throughout the world and are triggered by cosmetic reasons that oftentimes have deep historical, economic, sociocultural, and psychosocial roots. Exposure to chemicals in the bleaching products, notably, mercury (Hg), hydroquinone, and steroids, has been associated with a variety of adverse health effects, such as Hg poisoning and exogenous ochronosis. In New York City (NYC), skin care product use has been identified as an important route of Hg exposure, especially among Caribbean-born blacks and Dominicans...
November 11, 2016: Dermatology and Therapy
Antonella Peduto, Maria Scuotto, Verena Krauth, Fiorentina Roviezzo, Antonietta Rossi, Veronika Temml, Veronica Esposito, Hermann Stuppner, Daniela Schuster, Bruno D'Agostino, Chiara Schiraldi, Mario de Rosa, Oliver Werz, Rosanna Filosa
Aiming to assess the biological activities of synthetic 1,4-benzoquinones, we previously synthesized different libraries of benzoquinones with lipophilic and bulky alkyl- or aryl-substituents that inhibited 5-lipoxygenase (5-LO). The high potency of 4,5-dimethoxy-3-alkyl-1,2-benzoquinones on 5-LO led to the idea to further modify the structures and thus to improve the inhibitory potential in vitro and in vivo as well as to investigate SARs. Systematic structural optimization through accurate structure-based design resulted in compound 30 (3-tridecyl-4,5-dimethoxybenzene-1,2-diol), an ubiquinol derivative that exhibited the strongest anti-inflammatory effect, with a 10-fold improved 5-LO inhibitory activity (IC50 = 28 nM) in activated neutrophils...
October 22, 2016: European Journal of Medicinal Chemistry
Djemel Hamdane, Henri Grosjean, Marc Fontecave
RNA methylation is the most abundant and evolutionarily conserved chemical modification of bases or ribose in noncoding and coding RNAs. This rather simple modification has nevertheless major consequences on the function of maturated RNA molecules and ultimately on their cellular fates. The methyl group employed in the methylation is almost universally derived from S-adenosyl-L-methionine via a simple SN2 displacement reaction. However, in some rare cases, the carbon originates from N5,N10-methylenetetrahydrofolate (CH2=THF)...
November 5, 2016: Journal of Molecular Biology
K J Czogalla, M Watzka, J Oldenburg
Vitamin K 2,3-epoxide reductase complex, subunit 1 (VKORC1) is an enzyme essential for the vitamin K cycle. VKORC1 catalyses the reduction of vitamin K 2,3-epoxide to the quinone form of vitamin K and further to vitamin K hydroquinone. The generated vitamin K hydroquinone serves as substrate for the enzyme γ-glutamyl-carboxylase which modifies all vitamin K-dependent proteins, allowing them to bind calcium ions necessary for physiological activity. Vitamin K-dependent proteins include the coagulation factors FII, FVII, FIX, FX, and proteins C, S und Z...
November 8, 2016: Hämostaseologie
Isra Hassan, Julius Pavlov, Ramu Errabelli, Athula B Attygalle
1,4-Hydroquinone and several other phenolic compounds generate (M - 2) (-•) radical-anions, rather than deprotonated molecules, under certain negative-ion mass spectrometric conditions. In fact, spectra generated under helium-plasma ionization (HePI) conditions from 1,4-hydroquinone and 1,4-benzoquinone (by electron capture) were practically indistinguishable. Because this process involves a net loss of H(•) and H(+), it can be termed oxidative ionization. The superoxide radical-anion (O2(-•)), known to be present in many atmospheric-pressure plasma ion sources operated in the negative mode, plays a critical role in the oxidative ionization process...
November 7, 2016: Journal of the American Society for Mass Spectrometry
Malik Suliman Mohamed, Toshihide Maki, Mohammad Monir Shah, Yoshio Ichinose
Two hydroquinone derivatives were prepared and their antimicrobial activity evaluated. Their minimum inhibitory concentrations (MICs) were determined using a broth dilution method. Gentamycin and ciprofloxacin were used as reference antibiotics. The antimicrobial activity of 4-(benzyloxy)phenol (monobenzone) was also evaluated based on its structural similarity to the new compounds; activity was comparable to that of 3,5-dimethyl-4-((4-nitrobenzyl)oxy)phenol (4a). 2,3,5-Trimethyl-4-((4-nitrobenzyl)oxy)phenol (4b) exhibited the best antibacterial activity against both clinical isolates and type strain of Moraxella catarrhalis (M...
2016: Biological & Pharmaceutical Bulletin
Dipanjan Samanta, Joanne Widom, Peter P Borbat, Jack H Freed, Brian R Crane
Flagellated bacteria modulate their swimming behavior in response to environmental cues through the CheA/CheY signaling pathway. In addition to responding to external chemicals, bacteria also monitor internal conditions that reflect the availability of oxygen, light, and reducing equivalents - in a process termed ″Energy Taxis″. In E. coli, the transmembrane receptor Aer is the primary energy sensor for motility. Genetic and physiological data suggest that Aer monitors the electron transport chain through the redox state of its FAD cofactor...
November 1, 2016: Journal of Biological Chemistry
Alei Geng, Jian Wu, Rong-Rong Xie, Xia Li, Fu-Xiang Chang, Jian-Zhong Sun
Coptotermes formosanus Shiraki is a wood-feeding termite, which secretes a series of lignolytic and cellulolytic enzymes for woody biomass degradation. However, the lignin modification mechanism in termite is largely ellusive, and the characteristics of most lignolytic enzymes in termite remain unknown. In this study, a laccase gene lac1 from C. formosanus was heterogeneously expressed in insect Sf9 cells. The purified Lac1 showed strong activities toward hydroquinone (305 mU/mg) and 2,6-dimethoxyphenol (2...
November 1, 2016: Insect Science
Thi Mai Huong Tran, Adriano Ambrosi, Martin Pumera
Graphene oxide (GO) can be conveniently used as a starting material for the preparation of selective and sensitive electrochemical sensing systems. The amount of oxygen groups present on the material can be precisely tuned by reduction methodologies which allow the selection of the optimal C/O ratio for specific analytes. An electrochemical reduction procedure is used in this work to alter the oxygen content of the GO starting material and investigate the effects on the electrochemical detection of phenolic compounds selected with different hydroxyl groups: phenol, catechol, hydroquinone and phloroglucinol...
October 26, 2016: Physical Chemistry Chemical Physics: PCCP
Fang Miao, Ying Shi, Zhi-Feng Fan, Shan Jiang, Shi-Zheng Xu, Tie-Chi Lei
Safe and effective ingredients capable of removing undesired hyperpigmentation from facial skin are urgently needed for both pharmaceutical and cosmetic purposes. Deoxyarbutin (4-[(tetrahydro-2H-pyran-2-yl) oxy] phenol, D-Arb) is a glucoside derivative of hydroquinone. Here, we investigated the toxicity and efficacy of D-Arb at the sub-cellular level (directly on melanosomes) and skin pigmentation using in vivo and in vitro models to compare with its parent compound hydroquinone (1,4-benzenediol, HQ). At first, we examined the ultrastructural changes of melanosomes in hyperpigmented guinea pig skin induced by 308-nm monochromatic excimer lightand/or treated with HQ and D-Arb using transmission electron microscopy...
2016: PloS One
Mladen Lakić, Aleksandar Vukadinović, Kurt Kalcher, Aleksandar S Nikolić, Dalibor M Stanković
This work presents the simultaneous determination of catechol (CC) and hydroquinone (HQ), employing a modified carbon paste electrode (CPE) with ferrite nanomaterial. Ferrite nanomaterial was doped with different amount of cobalt and this was investigated toward simultaneous oxidation of CC and HQ. It was shown that this modification strongly increases electrochemical characteristics of the CPE. Also, electrocatalytic activity of such materials strongly depends on the level of substituted Co in the ferrite nanoparticles...
December 1, 2016: Talanta
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