The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Wen-qing Lu - One of the best experts on this subject based on the ideXlab platform.
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Toxicity of 2,6-dichloro-1,4-benzoquinone and five regulated drinking water disinfection by-products for the Caenorhabditis elegans nematode
Journal of Hazardous Materials, 2016Co-Authors: Yu-ting Zuo, Wen-qing Lu, Wei-wei Lu, Jing-jing Cao, Xue Han, Yu Hu, Fan Wang, Ai-lin LiuAbstract:Abstract Scarce toxicological data are available for 2,6-dichloro-1,4-benzoquinone (DCBQ), an emerging water disinfection by-product (DBP) that is of potential public health concern. This study investigated the effects of DCBQ on the lethality, respiration rate, and DNA damage in the Caenorhabditis elegans nematode. Meanwhile, the toxic effects of five regulated DBPs, dichloroacetic acid (DCA), trichloroacetic acid (TCA), monobromoacetic acid (MBA), dibromoacetic acid (DBA), and N-nitrosodimethylamine (NDMA), have also been evaluated. The tested DBPs increased the lethality and inhibited the respiration of C. elegans with an identical order of toxicity as follows: DCBQ > MBA > DBA > DCA > TCA > NDMA. The EC50 value (median concentration causing 50% reduction in respiration compared with untreated C. elegans ) is at least 30-fold lower than the corresponding LC50 value (median lethal concentration). Exposure to DCBQ and NDMA, but not to MBA, DBA, DCA, or TCA, resulted in DNA damage to C. elegans . The study suggested that DCBQ was more potent in inducing general toxicity than some regulated DBPs, and it revealed the in vivo genotoxic effect of DCBQ. Furthermore, the C. elegans -based bioassays may provide potentially useful tools for the toxicology assessment and ranking of DBPs.
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comparison of DNA damage in human derived hepatoma line hepg2 exposed to the fifteen drinking water disinfection byproducts using the single cell gel electrophoresis assay
Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2012Co-Authors: Li Zhang, Liang Xu, Qiang Zeng, Shaohui Zhang, Wen-qing LuAbstract:Abstract Disinfection of drinking water reduces pathogenic infection, but generates disinfection by-products (DBPs) in drinking water. In this study, the effect of fifteen DBPs on DNA damage in human-derived hepatoma line (HepG2) was investigated by the single cell gel electrophoresis (SCGE) assay. These fifteen DBPs are: four trihalomethanes (THMs), six haloacetic acides (HAAs), three haloacetonitriles (HANs), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), and chloral hydrate (CH). Based on the minimal effective concentration (MEC) at which DBPs induced significant increase in olive tail moment (OTM), the rank order of DNA-damaging potency is: bromodichloromethane (BDCM) > dibromochloromethane (DBCM) > tribromomethane (TBM) > trichloromethane (TCM) of the four THMs; iodoacetic acid (IA) > bromoacetic acid (BA) > dibromoacetic acid (DBA) > dichloracetic acid (DCA) > trichloroacetic acid (TCA) of the five HAAs; dibromoacetonitrile (DBN) ≈ dichloroacetonitrile (DCN) > trichloroacetonitrile (TCN) of the three HANs. The DNA damaging potency of MX and CH is similar to TCA and DCA, respectively. IA is the most genotoxic DBP in the fifteen DBPs, followed by BA. Chloroacetic acid (CA) is not genotoxic in this assay. Our findings indicated that HepG2/SCGE is a sensitive tool to evaluate the genotoxicity of DBPs and iodinated DBPs are more genotoxic than brominated DBPs, but chlorinated DBPs are less genotoxic than brominated DBPs.
Maria Marekova - One of the best experts on this subject based on the ideXlab platform.
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novel zinc complexes of a non steroidal anti inflammatory drug niflumic acid structural characterization human DNA and albumin binding properties
European Journal of Medicinal Chemistry, 2017Co-Authors: Romana Smolkova, Vladimir Zeleňak, Lukas Smolko, Juraj Kuchar, Miroslava Rabajdova, Michaela Ferencakova, Maria MarekovaAbstract:Abstract Three novel Zn(II) complexes of NSAID niflumic acid (H nif ) were prepared and studied, namely; [Zn(MeOH) 4 ( nif ) 2 ] ( 1 ), [Zn( cyclam )( nif ) 2 ] ( 2 ) and [Zn( nif ) 2 ( tmen )] ( 3 ), where nif is deprotonated niflumic acid, cyclam is 1,4,8,11-Tetraazacyclotetradecane and tmen is N,N,N′,N′-Tetramethylethylenediamine. The complexes have been characterized by infrared spectroscopy, elemental and thermal analysis and single-crystal X-ray structure analysis. All three complexes contain two deprotonated niflumato anions monodentately coordinated via carboxylato groups. Furthermore, fluorescence binding studies of the prepared compounds with human genomic DNA-EB (ethidium bromide) were carried out, which suggest that all complexes are able to bind to DNA via intercalation. Moreover, from the obtained results it followed that complexes 2 and 3 bind to DNA from the tissue with aortic aneurysm (aDNA) and control (cDNA) with a different strength. Additionally, complexes 1-3 exhibit good binding affinity to human serum albumin with high binding constant.
B I Sukhorukov - One of the best experts on this subject based on the ideXlab platform.
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structural and thermodynamic features of complexes formed by DNA and synthetic polynucleotides with dodecylamine and dodecyltrimethylammonium bromide
Bioelectrochemistry, 2002Co-Authors: A I Petrov, D N Khalil, R L Kazaryan, I V Savintsev, B I SukhorukovAbstract:Abstract Complex formation of native and denatured DNA, single-stranded polyribonucleotides poly(A) and poly(U), as well as double-stranded poly(A)·poly(U) with dodecylamine (DDA) and dodecyltrimethylammonium bromide (DTAB) has been studied by UV-, CD-, IR-spectroscopy and fluorescence analysis of hydrophobic probe pyrene. DDA and DTAB were shown to bind cooperatively with DNA and polyribonucleotides, resulting in the formation of complexes containing hydrophobic micelle-like clusters. Critical aggregation concentration (CAC) of DDA and DTAB shifts sharply to lower values (30–50 times) in the presence of DNA and polynucleotides as compared to critical micelle concentration (CMC) of free DDA and DTAB in solution. The analysis of binding isotherms within the frame of the model of cooperative binding of low-molecular ligands to linear polymers allowed us to determine the thermodynamic parameters of complex formation and estimate the contribution of electrostatic interaction of positively charged heads of amphiphiles with negatively charged phosphate groups of DNA and polyribonucleotides, and hydrophobic interaction of aliphatic chains to complex stability. Electrostatic interaction was shown to make the main contribution to the stability of DNA complexes with DDA, while preferential contribution of hydrophobic interactions is characteristic of DTAB complexes with DNA. The opposite effect of DDA and DTAB on the thermal stability of DNA double helix was demonstrated from UV-melting of DNA—while DTAB stabilizes the DNA helix, DDA, to the contrary, destabilizes it. The destabilizing effect of DDA seems to originate from the displacement of intramolecular hydrogen bonds in complementary Watson–Crick A·T and G·C base pairs with intermolecular H-bonds between unsubstituted DDA amino groups and proton-accepting sites of nucleic bases.
Takemi Enomoto - One of the best experts on this subject based on the ideXlab platform.
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Molecular cloning of a cDNA encoding mouse DNA helicase B, which has homology to Escherichia coli RecD protein, and identification of a mutation in the DNA helicase B from tsFT848 temperature-sensitive DNA replication mutant cells
Nucleic acids research, 2001Co-Authors: Shusuke Tada, Yukio Ishimi, Takayuki Kobayashi, Akira Omori, Yumiko Kusa, Natsuko Okumura, Hiroyo Kodaira, Masayuki Seki, Takemi EnomotoAbstract:DNA helicase B is a major DNA helicase in mouse FM3A cells. A temperature-sensitive mutant defective in DNA replication, tsFT848, isolated from FM3A cells, has a heat-labile DNA helicase B. In this study, we purified DNA helicase B from mouse FM3A cells and determined partial amino acid sequences of the purified protein. By using a DNA probe synthesized according to one of the partial amino acid sequences, a cDNA was isolated, which encoded a 121.5 kDa protein containing seven conserved motifs for DNA/RNA helicase superfamily members. A database search revealed similarity between DNA helicase B and the α subunit of exodeoxyribonuclease V of a number of prokaryotes including Escherichia coli RecD protein, but no homologous protein was found in yeast. The cDNA encoding DNA helicase B from tsFT848 was sequenced and a mutation was found between DNA/RNA helicase motifs IV and V.
Romana Smolkova - One of the best experts on this subject based on the ideXlab platform.
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novel zinc complexes of a non steroidal anti inflammatory drug niflumic acid structural characterization human DNA and albumin binding properties
European Journal of Medicinal Chemistry, 2017Co-Authors: Romana Smolkova, Vladimir Zeleňak, Lukas Smolko, Juraj Kuchar, Miroslava Rabajdova, Michaela Ferencakova, Maria MarekovaAbstract:Abstract Three novel Zn(II) complexes of NSAID niflumic acid (H nif ) were prepared and studied, namely; [Zn(MeOH) 4 ( nif ) 2 ] ( 1 ), [Zn( cyclam )( nif ) 2 ] ( 2 ) and [Zn( nif ) 2 ( tmen )] ( 3 ), where nif is deprotonated niflumic acid, cyclam is 1,4,8,11-Tetraazacyclotetradecane and tmen is N,N,N′,N′-Tetramethylethylenediamine. The complexes have been characterized by infrared spectroscopy, elemental and thermal analysis and single-crystal X-ray structure analysis. All three complexes contain two deprotonated niflumato anions monodentately coordinated via carboxylato groups. Furthermore, fluorescence binding studies of the prepared compounds with human genomic DNA-EB (ethidium bromide) were carried out, which suggest that all complexes are able to bind to DNA via intercalation. Moreover, from the obtained results it followed that complexes 2 and 3 bind to DNA from the tissue with aortic aneurysm (aDNA) and control (cDNA) with a different strength. Additionally, complexes 1-3 exhibit good binding affinity to human serum albumin with high binding constant.