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Yaping Wang, Chao Yang, Wen Xue, Ting Zhang, Xipei Liu, Jiansong Ju, Baohua Zhao, Dong Liu
BACKGROUND: Combining experimental and computational screening methods has been of keen interest in drug discovery. In the present study, we developed an efficient screening method that has been used to screen 2100 small-molecule compounds for alanine racemase Alr-2 inhibitors. RESULTS: We identified ten novel non-substrate Alr-2 inhibitors, of which patulin, homogentisic acid, and hydroquinone were active against Aeromonas hydrophila. The compounds were found to be capable of inhibiting Alr-2 to different extents with 50% inhibitory concentrations (IC50) ranging from 6...
May 25, 2017: BMC Microbiology
Xiao-Long Xu, Zhi Li
Allylation and benzylation of p-quinones is achieved by an unusual redox chain reaction. Mechanistic studies suggest that the trace existence of hydroquinone initiates a redox chain reaction that consists of a Lewis acid-catalyzed Friedel-Crafts alkylation and a subsequent redox equilibrium that regenerates hydroquinone. The electrophiles could be various allylic and benzylic esters. Addition of Hantzsch ester as initiator improves the efficiency of the reaction.
May 22, 2017: Angewandte Chemie
Yong Yu, Xin Ting Zheng, Boon Wei Yee, Yen Nee Tan
Bioluminescence has been widely recognized as a powerful imaging tool for biological investigations. Synthesis of molecular lanterns that mimic bioluminescence in nature is of great interest. Herein we report a synthesis of molecular lantern by utilizing the catalytic properties of ultrasmall (<2nm) gold nanoclusters (AuNC), which is inspired by the enzymatic light-up of luciferin in the biological system. Small molecules such as hydroquinone and Cys-Gly peptides are used to direct the synthesis of AuNC via a biotemplating approach, while the in-situ formation of AuNC simultaneously catalyze the formation of luciferin-like, brightly fluorescent dye (λem=520nm, QY=0...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Amin Daryaei, Gregory C Miller, Jason Willey, Shreya Roy-Choudhury, Britannia Vondrasek, Dana Kazerooni, Matthew Russell Burtner, Cortney Kenneth Mittelsteadt, John J Lesko, Judy S Riffle, James E McGrath
Two series of high molecular weight disulfonated poly(arylene ether sulfone) random copolymers were synthesized as proton exchange membranes for high temperature water electrolyzers. These copolymers differ based on the position of the ether bonds on the aromatic rings. One series is comprised of fully para-substituted hydroquinone comonomer and the other series incorporated 25 mole % of a meta-substituted comonomer, resorcinol, and 75 mole % hydroquinone. The influence of the substitution position on water uptake and electrochemical properties of the membranes were investigated and compared to that of the state-of-the-art membrane, Nafion™...
May 22, 2017: ACS Applied Materials & Interfaces
Baosong Chen, Jin Tian, Jinjin Zhang, Kai Wang, Li Liu, Bo Yang, Li Bao, Hongwei Liu
Seven new compounds including four lanostane triterpenoids, lucidenic acids Q-S (1-3) and methyl ganoderate P (4), and three triterpene-farnesyl hydroquinone conjugates, ganolucinins A-C (5-7), one new natural product ganomycin J (8), and 73 known compounds (9-81) were isolated from fruiting bodies of Ganoderma lucidum. The structures of the compounds 1-8 were determined by spectroscopic methods. Bioactivities of compounds isolated were assayed against HMG-CoA reductase, aldose reductase, α-glucosidase, and PTP1B...
May 17, 2017: Fitoterapia
Frances M Munoz, Fengjiao Zhang, Argel Islas-Robles, Serrine S Lau, Terrence J Monks
2,3,5-tris(Glutathion-S-yl)hydroquinone (TGHQ), a potent nephrotoxic and nephrocarcinogenic metabolite of benzene and hydroquinone, generates reactive oxygen species (ROS) causing DNA strand breaks and the subsequent activation of DNA repair enzymes, including poly(ADP-ribose) polymerase (PARP)-1. Under robust oxidative DNA damage, PARP-1 is hyperactivated, resulting in the depletion of NAD+ and ATP with accompanying elevations in intracellular calcium concentrations (iCa2+), and ultimately necrotic cell death...
May 19, 2017: Toxicological Sciences: An Official Journal of the Society of Toxicology
Su Yeon Cho, Oh Sung Kwean, Jun Won Yang, Wooyoun Cho, Seonyeong Kwak, Sungyoon Park, Yejee Lim, Han S Kim
This study aimed to clarify the initial 4-chlorophenol (4-CP) biodegradation pathway promoted by a two-component flavin-diffusible monooxygenase (TC-FDM) consisting of CphC-I and CphB contained in Arthrobacter chlorophenolicus A6 and the decomposition function of CphC-I. The TC-FDM genes were cloned from A. chlorophenolicus A6, and the corresponding enzymes were overexpressed. Since CphB was expressed in an insoluble form, Fre, a flavin reductase obtained from Escherichia coli, was used. These enzymes were purified using Ni(2+)-NTA resin...
May 4, 2017: Bioresource Technology
Minjun Yang, Christopher Batchelor-McAuley, Enno Kätelhön, Richard G Compton
The chemical confinement of a pH sensitive fluorophore to a thin-reaction layer adjacent to an electrode surface is explored as innovative route to improving the spatial resolution of fluorescence electrochemical microscopy. A thin layer opto-electrochemical cell is designed, facilitating the visualisation of a carbon fibre (diameter 7.0 um) electrochemical interface. Proton consumption is driven at the interface by the reduction of benzoquinone to hydroquinone and the resulting interfacial pH change is revealed using the fluorophore 8-hydoxypyrene-1,3,6-trisulfonic acid...
May 18, 2017: Analytical Chemistry
Yu Seok Jung, Ji Hae Lee, Jung Min Bae, Dong Won Lee, Gyong Moon Kim
BACKGROUND: Medical products such as hydroquinone and tretinoin have been widely used to treat various types of skin hyperpigmentation. However, these products are limited in daily use given their adverse effects. Other alternative agents with fewer adverse side effects have been developed. However, single agents often do not produce satisfactory results. AIMS: To evaluate the efficacy and safety of a new brightening complex cream containing niacinamide, tranexamic acid, oxyresveratrol, glutathione disulfide, and linoleic acid...
May 16, 2017: Journal of Cosmetic Dermatology
Longmei Xu, Jiaxian Liu, Yuting Chen, Lin Yun, Shaoyun Chen, Kairu Zhou, Bei Lai, Li Song, Hui Yang, Hairong Liang, Huanwen Tang
No abstract text is available yet for this article.
May 13, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
Juan Feng, Xiaoqiang Lei, Zhen Guo, Yefeng Tang
We report the concise total synthesis of homodimericin A (1), a recently identified fungal metabolite bearing an unprecedented molecular architecture. The success of the approach hinges on a series of rationally designed and bioinspired transformations, including a Moore rearrangement to assemble the monomeric hydroquinone precursor, homodimerization through double Michael addition to construct the planar A/B/C tricyclic framework, and a tandem Diels-Alder reaction/carbonyl-ene cyclization to forge the congested D/E/F tricyclic cage motif...
May 16, 2017: Angewandte Chemie
Antonio Garcia-Jimenez, Jose Antonio Teruel-Puche, Jose Berna, José Neptuno Rodriguez-Lopez, Jose Tudela, Francisco Garcia-Canovas
The known derivatives from hydroquinone, α and β-arbutin, are used as depigmenting agents. In this work, we demonstrate that the oxy form of tyrosinase (oxytyrosinase) hydroxylates α and β-arbutin in ortho position of the phenolic hydroxyl group, giving rise to a complex formed by met-tyrosinase with the hydroxylated α or β-arbutin. This complex could evolve in two ways: by oxidizing the originated o-diphenol to o-quinone and deoxy-tyrosinase, or by delivering the o-diphenol and met-tyrosinase to the medium, which would produce the self-activation of the system...
2017: PloS One
Jacopo Troisi, Luca Pierri, Annamaria Landolfi, Francesca Marciano, Antonella Bisogno, Federica Belmonte, Carmen Palladino, Salvatore Guercio Nuzio, Pietro Campiglia, Pietro Vajro
To get insight into still elusive pathomechanisms of pediatric obesity and non-alcoholic fatty liver disease (NAFLD) we explored the interplay among GC-MS studied urinary metabolomic signature, gut liver axis (GLA) abnormalities, and food preferences (Kid-Med). Intestinal permeability (IP), small intestinal bacterial overgrowth (SIBO), and homeostatic model assessment-insulin resistance were investigated in forty children (mean age 9.8 years) categorized as normal weight (NW) or obese (body mass index <85th or >95th percentile, respectively) ± ultrasonographic bright liver and hypertransaminasemia (NAFLD)...
May 11, 2017: Nutrients
Masaaki Yusa, Toshi Nagata
Under the irradiation of red light (690 nm), quinones were converted to hydroquinones by thiols in the presence of metallophthalocyanines. The reaction proceeded via the charge separation between the triplet state of phthalocyanine and the quinone. The product determining step was protonation of the quinone anion radical, as indicated by the fact that the reaction was accelerated by the use of more acidic thiols or addition of an acid.
May 9, 2017: Photochemical & Photobiological Sciences
Meng-Xi Li, Xing-Hua Wang, Lian-Ming Zhang, Xiao-Ping Wei
To improve the sensitivity of the molecular imprinting sensor detection of protein, a new strategy based on enzyme amplification was proposed. The determination of bovine serum albumin (BSA) was achieved by using the epitope imprinted techniques coupling with electrochemical measurement method. Nonapeptide, separated from BSA, was selected as a template molecule to prepare the molecularly imprinted polymer (MIP) film, and it could bind with the cavities of the MIP. By the use of epitope imprinted techniques, BSA can be recognized by the MIP via the nonapeptide on the surface of BSA...
May 5, 2017: Analytical Biochemistry
Lili Shi, Siuming Chan, Chaozheng Li, Shuang Zhang
Phenoloxidases (POs) are a family of enzymes including tyrosinases, catecholases and laccases, which play an important role in immune defences of various invertebrates. Whether or not laccase exists in shrimp and its function is still poorly understood. In this study, a laccase (LvLac) was cloned and identified from Litopenaeus vannamei for the first time. The full length of LvLac is 3406 bp, including a 2034 bp open reading frame (ORF) coding for a putative protein of 677 amino acids with a signal peptide of 33 aa...
May 3, 2017: Fish & Shellfish Immunology
Nai-Fang Chang, Yi-Shyan Chen, Ying-Ju Lin, Ting-Hsuan Tai, An-Ni Chen, Chen-Hsuan Huang, Chih-Chien Lin
Arbutin (Arb) and deoxyArbutin (dA) are both effective hypopigmentation agents. However, they are glucoside derivatives of hydroquinone (HQ), which may be decayed into HQ under higher energy environments. Therefore, safety and toxicity are very important issues when considering the usage of these compounds. However, no study has verified the properties of Ultra-Violet B (UVB)-irradiated Arb and dA. In this work, we investigated the cytotoxicity and hypopigmentation effects of UVB-irradiated Arb and dA in Detroit 551 human fibroblast cells and B16-F10 mouse melanoma cells...
May 3, 2017: International Journal of Molecular Sciences
Young-Su Yi, Mi-Yeon Kim, Jae Youl Cho
Since previous studies have reported that hydroquinone (HQ) exerted immunosuppressive and anti-inflammatory activity, various HQ derivatives have been synthesized and their biological activities investigated. In this study, we explored the anti-inflammatory activity of JS-III-49, a novel HQ derivative, in macrophage-mediated inflammatory responses. JS-III-49 suppressed the production of the inflammatory mediators nitric oxide (NO) and prostaglandin E2 (PGE2) and down-regulated the mRNA expression of the inflammatory enzymes cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as well as the expression of the pro-inflammatory cytokines interleukin-6 (IL-6) and IL-1b without cytotoxicity in LPS-stimulated RAW264...
May 2017: Korean Journal of Physiology & Pharmacology
Regina Stabbert, Ruth Dempsey, Joerg Diekmann, Christian Euchenhofer, Timo Hagemeister, Hans-Juergen Haussmann, Arno Knorr, Boris P Mueller, Pavel Pospisil, Wolf Reininghaus, Ewald Roemer, Franz J Tewes, Detlef J Veltel
Tobacco smoke is a complex mixture with over 8700 identified constituents. Smoking causes many diseases including lung cancer, cardiovascular disease, and chronic obstructive pulmonary disease. However, the mechanisms of how cigarette smoke impacts disease initiation or progression are not well understood and individual smoke constituents causing these effects are not generally agreed upon. The studies reported here were part of a series of investigations into the contributions of selected smoke constituents to the biological activity of cigarette smoke...
April 28, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
Supakarn Chamni, Natchanun Sirimangkalakitti, Pithi Chanvorachote, Naoki Saito, Khanit Suwanborirux
A series of hydroquinone 5-O-monoester analogues of renieramycin M were semisynthesized via bishydroquinonerenieramycin M (5) prepared from renieramycin M (1), a major cytotoxic bistetrahydroisoquinolinequinone alkaloid isolated from the Thai blue sponge Xestospongia sp. All 20 hydroquinone 5-O-monoester analogues possessed cytotoxicity with IC50 values in nanomolar concentrations against the H292 and H460 human non-small-cell lung cancer (NSCLC) cell lines. The improved cytotoxicity toward the NSCLC cell lines was observed from the 5-O-monoester analogues such as 5-O-acetyl ester 6a and 5-O-propanoyl ester 7e, which exhibited 8- and 10-fold increased cytotoxicity toward the H292 NSCLC cell line (IC50 3...
May 1, 2017: Journal of Natural Products
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