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M Swaminathan - One of the best experts on this subject based on the ideXlab platform.
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Correction: Nano N-TiO2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes
RSC Advances, 2020Co-Authors: K Selvam, M SwaminathanAbstract:Correction for ‘Nano N-TiO2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes’ by Kaliyamoorthy Selvam et al., RSC Adv., 2012, 2, 2848–2855, DOI: 10.1039/C2RA01178F.
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nano n tio2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes
ChemInform, 2012Co-Authors: K Selvam, M SwaminathanAbstract:N-Doped titanium dioxide is successfully applied as catalyst in the photo-induced reaction of nitrobenzenes (I) with ethanol to give Quinaldine derivatives (III).
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Nano N‐TiO2 Mediated Selective Photocatalytic Synthesis of Quinaldines from Nitrobenzenes.
ChemInform, 2012Co-Authors: K Selvam, M SwaminathanAbstract:N-Doped titanium dioxide is successfully applied as catalyst in the photo-induced reaction of nitrobenzenes (I) with ethanol to give Quinaldine derivatives (III).
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nano n tio2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes
RSC Advances, 2012Co-Authors: K Selvam, M SwaminathanAbstract:N-Doped TiO2 using a new nitrogen precursor hydrazine hydrate was synthesized by a simple wet method. This photocatalyst was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, high resolution transmission electron microscopy (HR-TEM), UV-Vis diffused reflectance spectra (DRS), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). N-Doping does not change the phase of TiO2. It is found that the size of N-TiO2 is 15.6 nm with 134.72 m² g−1 surface area. XPS analysis reveals the presence of anionic nitrogen in TiO2 as O–Ti–N. Substitution of N in place of oxygen in the TiO2 lattice causes a decrease in oxygen vacancies which inhibits the recombination of electron–hole pairs. This catalyst was used for the selective one-pot synthesis of Quinaldines from nitrobenzenes in ethanol under UV and visible light. N-TiO2 on irradiation induces a combined redox reaction with nitrobenzene and alcohol and this is followed by condensation-cyclization of aniline with oxidation products to give Quinaldines. N-Doped TiO2 is found to be more efficient than metal doped TiO2 in Quinaldine synthesis under visible light. Higher activity of the N-TiO2 could be attributed to its stronger absorbance of visible light.
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RETRACTED ARTICLE: Nano Pt–TiO_2 for an efficient one-pot photocatalytic synthesis of Quinaldines from anilines and ethanol
Research on Chemical Intermediates, 2012Co-Authors: K Selvam, Bojja Sreedhar, M SwaminathanAbstract:Nanosized platinum particles loaded on the TiO_2 nanoparticles were prepared to assess its photocatalytic activity in simple one-pot synthesis of Quinaldines from anilines in ethanol using UV light. The catalyst was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy, X-ray photoelectron spectra (XPS), Brunauer – Emmer–Teller surface area, atomic force microscope and diffuse reflectance spectra. XRD patterns revealed that the crystal structure of Pt–TiO_2 resembled anatase phase of TiO_2. The UV–Vis spectra indicated an increase in absorption of visible light when compared to TiO_2. XPS analysis reveals that platinum particles are present mainly in metallic form. Furthermore, TEM analysis showed non-spherical-shaped Pt–TiO_2 nanoparticles of the diameter 10–30 nm. Upon irradiation in the presence of Pt–TiO_2, aniline and oxidation products derived from ethanol undergo condensation–cyclization to afford Quinaldines. Higher efficiency of Pt–TiO_2 than Au–TiO_2 in the conversion of aniline to Quinaldines is due to the higher work function of Pt.
K Selvam - One of the best experts on this subject based on the ideXlab platform.
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Correction: Nano N-TiO2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes
RSC Advances, 2020Co-Authors: K Selvam, M SwaminathanAbstract:Correction for ‘Nano N-TiO2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes’ by Kaliyamoorthy Selvam et al., RSC Adv., 2012, 2, 2848–2855, DOI: 10.1039/C2RA01178F.
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nano n tio2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes
ChemInform, 2012Co-Authors: K Selvam, M SwaminathanAbstract:N-Doped titanium dioxide is successfully applied as catalyst in the photo-induced reaction of nitrobenzenes (I) with ethanol to give Quinaldine derivatives (III).
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Nano N‐TiO2 Mediated Selective Photocatalytic Synthesis of Quinaldines from Nitrobenzenes.
ChemInform, 2012Co-Authors: K Selvam, M SwaminathanAbstract:N-Doped titanium dioxide is successfully applied as catalyst in the photo-induced reaction of nitrobenzenes (I) with ethanol to give Quinaldine derivatives (III).
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nano n tio2 mediated selective photocatalytic synthesis of Quinaldines from nitrobenzenes
RSC Advances, 2012Co-Authors: K Selvam, M SwaminathanAbstract:N-Doped TiO2 using a new nitrogen precursor hydrazine hydrate was synthesized by a simple wet method. This photocatalyst was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, high resolution transmission electron microscopy (HR-TEM), UV-Vis diffused reflectance spectra (DRS), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). N-Doping does not change the phase of TiO2. It is found that the size of N-TiO2 is 15.6 nm with 134.72 m² g−1 surface area. XPS analysis reveals the presence of anionic nitrogen in TiO2 as O–Ti–N. Substitution of N in place of oxygen in the TiO2 lattice causes a decrease in oxygen vacancies which inhibits the recombination of electron–hole pairs. This catalyst was used for the selective one-pot synthesis of Quinaldines from nitrobenzenes in ethanol under UV and visible light. N-TiO2 on irradiation induces a combined redox reaction with nitrobenzene and alcohol and this is followed by condensation-cyclization of aniline with oxidation products to give Quinaldines. N-Doped TiO2 is found to be more efficient than metal doped TiO2 in Quinaldine synthesis under visible light. Higher activity of the N-TiO2 could be attributed to its stronger absorbance of visible light.
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RETRACTED ARTICLE: Nano Pt–TiO_2 for an efficient one-pot photocatalytic synthesis of Quinaldines from anilines and ethanol
Research on Chemical Intermediates, 2012Co-Authors: K Selvam, Bojja Sreedhar, M SwaminathanAbstract:Nanosized platinum particles loaded on the TiO_2 nanoparticles were prepared to assess its photocatalytic activity in simple one-pot synthesis of Quinaldines from anilines in ethanol using UV light. The catalyst was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy, X-ray photoelectron spectra (XPS), Brunauer – Emmer–Teller surface area, atomic force microscope and diffuse reflectance spectra. XRD patterns revealed that the crystal structure of Pt–TiO_2 resembled anatase phase of TiO_2. The UV–Vis spectra indicated an increase in absorption of visible light when compared to TiO_2. XPS analysis reveals that platinum particles are present mainly in metallic form. Furthermore, TEM analysis showed non-spherical-shaped Pt–TiO_2 nanoparticles of the diameter 10–30 nm. Upon irradiation in the presence of Pt–TiO_2, aniline and oxidation products derived from ethanol undergo condensation–cyclization to afford Quinaldines. Higher efficiency of Pt–TiO_2 than Au–TiO_2 in the conversion of aniline to Quinaldines is due to the higher work function of Pt.
Hiroyuki Nishide - One of the best experts on this subject based on the ideXlab platform.
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a hydrogen storing Quinaldine polymer nickel electrodeposition assisted hydrogenation and subsequent hydrogen evolution
Polymer International, 2017Co-Authors: Ryo Kato, Takahiro Oya, Yuma Shimazaki, Kenichi Oyaizu, Hiroyuki NishideAbstract:Quinaldine-substituted poly(acrylic acid) (PQD) and its hydrogenated 1,2,3,4-tetrahydroQuinaldine derivative (PHQD) were prepared, and a cycle of hydrogen fixing and hydrogen evolution in and from the polymer, respectively, is described. A PQD layer coated on a carbon substrate was electrochemically reduced or hydrogenated using water as a hydrogen source, accompanied by the electrodeposition of nickel microparticles in the polymer layer, to convert PQD to PHQD. The conversion efficiency was enhanced by coating PQD on the substrate as a scaffold of nickel electrodeposition, in comparison with that of Quinaldine and PQD dissolved in the electrolyte. The formed PHQD evolved hydrogen by simply warming it in water containing an iridium complex catalyst. Hydrogen fixing and evolution under mild conditions could suggest a new system of hydrogen carriers. © 2017 Society of Chemical Industry
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A hydrogen‐storing Quinaldine polymer: nickel‐electrodeposition‐assisted hydrogenation and subsequent hydrogen evolution
Polymer International, 2017Co-Authors: Ryo Kato, Takahiro Oya, Yuma Shimazaki, Kenichi Oyaizu, Hiroyuki NishideAbstract:Quinaldine-substituted poly(acrylic acid) (PQD) and its hydrogenated 1,2,3,4-tetrahydroQuinaldine derivative (PHQD) were prepared, and a cycle of hydrogen fixing and hydrogen evolution in and from the polymer, respectively, is described. A PQD layer coated on a carbon substrate was electrochemically reduced or hydrogenated using water as a hydrogen source, accompanied by the electrodeposition of nickel microparticles in the polymer layer, to convert PQD to PHQD. The conversion efficiency was enhanced by coating PQD on the substrate as a scaffold of nickel electrodeposition, in comparison with that of Quinaldine and PQD dissolved in the electrolyte. The formed PHQD evolved hydrogen by simply warming it in water containing an iridium complex catalyst. Hydrogen fixing and evolution under mild conditions could suggest a new system of hydrogen carriers. © 2017 Society of Chemical Industry
Susanne Fetzner - One of the best experts on this subject based on the ideXlab platform.
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Complete genome sequence and metabolic potential of the Quinaldine-degrading bacterium Arthrobacter sp. Rue61a
BMC genomics, 2012Co-Authors: Heiko Niewerth, Katja Parschat, Jörg Schuldes, Patrick Kiefer, Julia A Vorholt, Rolf Daniel, Susanne FetznerAbstract:Background Bacteria of the genus Arthrobacter are ubiquitous in soil environments and can be considered as true survivalists. Arthrobacter sp. strain Rue61a is an isolate from sewage sludge able to utilize Quinaldine (2-methylquinoline) as sole carbon and energy source. The genome provides insight into the molecular basis of the versatility and robustness of this environmental Arthrobacter strain.
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Complete genome sequence and metabolic potential of the Quinaldine-degrading bacterium Arthrobacter sp. Rue61a
BMC Genomics, 2012Co-Authors: Heiko Niewerth, Katja Parschat, Jörg Schuldes, Patrick Kiefer, Julia A Vorholt, Rolf Daniel, Susanne FetznerAbstract:Background Bacteria of the genus Arthrobacter are ubiquitous in soil environments and can be considered as true survivalists. Arthrobacter sp. strain Rue61a is an isolate from sewage sludge able to utilize Quinaldine (2-methylquinoline) as sole carbon and energy source. The genome provides insight into the molecular basis of the versatility and robustness of this environmental Arthrobacter strain. Results The genome of Arthrobacter sp. Rue61a consists of a single circular chromosome of 4,736,495 bp with an average G + C content of 62.32%, the circular 231,551-bp plasmid pARUE232, and the linear 112,992-bp plasmid pARUE113 that was already published. Plasmid pARUE232 is proposed to contribute to the resistance of Arthrobacter sp. Rue61a to arsenate and Pb^2+, whereas the linear plasmid confers the ability to convert Quinaldine to anthranilate. Remarkably, degradation of anthranilate exclusively proceeds via a CoA-thioester pathway. Apart from Quinaldine utilization, strain Rue61a has a limited set of aromatic degradation pathways, enabling the utilization of 4-hydroxy-substituted aromatic carboxylic acids, which are characteristic products of lignin depolymerization, via ortho cleavage of protocatechuate. However, 4-hydroxyphenylacetate degradation likely proceeds via meta cleavage of homoprotocatechuate. The genome of strain Rue61a contains numerous genes associated with osmoprotection, and a high number of genes coding for transporters. It encodes a broad spectrum of enzymes for the uptake and utilization of various sugars and organic nitrogen compounds. A . aurescens TC-1 is the closest sequenced relative of strain Rue61a. Conclusions The genome of Arthrobacter sp. Rue61a reflects the saprophytic lifestyle and nutritional versatility of the organism and a strong adaptive potential to environmental stress. The circular plasmid pARUE232 and the linear plasmid pARUE113 contribute to heavy metal resistance and to the ability to degrade Quinaldine, respectively.
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Complete Nucleotide Sequence of the 113-Kilobase Linear Catabolic Plasmid pAL1 of Arthrobacter nitroguajacolicus Rü61a and Transcriptional Analysis of Genes Involved in Quinaldine Degradation
Journal of bacteriology, 2007Co-Authors: Katja Parschat, Jörg Overhage, Axel Strittmatter, Anke Henne, Gerhard Gottschalk, Susanne FetznerAbstract:The nucleotide sequence of the linear catabolic plasmid pAL1 from the 2-methylquinoline (Quinaldine)-degrading strain Arthrobacter nitroguajacolicus Ru61a comprises 112,992 bp. A total of 103 open reading frames (ORFs) were identified on pAL1, 49 of which had no annotatable function. The ORFs were assigned to the following functional groups: (i) catabolism of Quinaldine and anthranilate, (ii) conjugation, and (iii) plasmid maintenance and DNA replication and repair. The genes for conversion of Quinaldine to anthranilate are organized in two operons that include ORFs presumed to code for proteins involved in assembly of the Quinaldine-4-oxidase holoenzyme, namely, a MobA-like putative molybdopterin cytosine dinucleotide synthase and an XdhC-like protein that could be required for insertion of the molybdenum cofactor. Genes possibly coding for enzymes involved in anthranilate degradation via 2-aminobenzoyl coenzyme A form another operon. These operons were expressed when cells were grown on Quinaldine or on aromatic compounds downstream in the catabolic pathway. Single-stranded 3′ overhangs of putative replication intermediates of pAL1 were predicted to form elaborate secondary structures due to palindromic and superpalindromic terminal sequences; however, the two telomeres appear to form different structures. Sequence analysis of ORFs 101 to 103 suggested that pAL1 codes for one or two putative terminal proteins, presumed to be covalently bound to the 5′ termini, and a multidomain telomere-associated protein (Tap) comprising 1,707 amino acids. Even if the putative proteins encoded by ORFs 101 to 103 share motifs with the Tap and terminal proteins involved in telomere patching of Streptomyces linear replicons, their overall sequences and domain structures differ significantly.
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Spectroscopic and biochemical studies on protein variants of Quinaldine 4-oxidase: Role of E736 in catalysis and effects of serine ligands on the FeSI and FeSII clusters.
Biochemistry, 2006Co-Authors: Reinhard Kappl, Katja Parschat, Jürgen Hüttermann, Sonja Sielker, Kalina Ranguelova, Jeannine Wegner, Susanne FetznerAbstract:Quinaldine 4-oxidase (Qox), which catalyzes the hydroxylation of Quinaldine to 1H-4-oxoQuinaldine, is a heterotrimeric (LMS) 2 molybdo-iron/sulfur flavoprotein belonging to the xanthine oxidase family. Variants of Qox were generated by site-directed mutagenesis. Replacement in the large subunit at E736, which is presumed to be located close to the molybdenum, by aspartate (Qox L E736D) resulted in a marked decrease in k cat app for Quinaldine, while K m app was largely unaffected. Although a minor reduction of the glutamine substituted variant Qox L E736Q by Quinaldine occurred, its activity was below detection, indicating that the carboxylate group of E736 is crucial for catalysis. Replacement of cysteine ligands C40, C45, or C60 (FeSII) and of the C120 or C154 ligands to FeSI in the small subunit of Qox by serine led to decreased iron contents of the protein preparations. Substitutions C40S and C45S (Fel of FeSII) suppressed the characteristic FeSII EPR signals and significantly reduced catalytic activity. In QoxsC154S (Fe1 of FeSI), the g-factor components of FeSI were drastically changed. In contrast, Qox proteins with substitutions of C48 and C60 (Fe2 of FeSII), and of the C120 ligand at Fe2 of FeSI, retained considerable activity and showed less pronounced changes in their EPR parameters. Taken together, the properties of the Qox variants suggest that Fel of both FeSI and FeSII are the reducible iron sites, whereas the Fe2 ions remain in the ferric state. The location of the reducible iron sites of FeSI and FeSII appears to be conserved in enzymes of the xanthine oxidase family.
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Identification of large linear plasmids in Arthrobacter spp. encoding the degradation of Quinaldine to anthranilate.
Microbiology, 2005Co-Authors: Jörg Overhage, Katja Parschat, Sonja Sielker, Stefan Homburg, Susanne FetznerAbstract:Arthrobacter nitroguajacolicus Ru61a, which utilizes Quinaldine as sole source of carbon and energy, was shown to contain a conjugative linear plasmid of approximately 110 kb, named pAL1. It exhibits similarities with other linear plasmids from Actinomycetales in that it has proteins covalently attached to its 5′ ends. Southern hybridization with probes for the genes encoding Quinaldine 4-oxidase and N-acetylanthranilate amidase indicated that pAL1 contains the gene cluster encoding the degradation of Quinaldine to anthranilate. A mutant of strain Ru61a that had lost pAL1 indeed could not convert Quinaldine, but was still able to grow on anthranilate. Conjugative transfer of pAL1 to the plasmid-less mutant of strain Ru61a and to Arthrobacter nicotinovorans DSM 420 (pAO1) occurred at frequencies of 5·4×10−4 and 2·0×10−4 per recipient, respectively, and conferred the ability to utilize Quinaldine. Five other Quinaldine-degrading Gram-positive strains were isolated from soil samples; 16S rDNA sequence analysis suggested the closest relationship to different Arthrobacter species. Except for strain K2-29, all isolates contained a pAL1-like linear plasmid carrying genes encoding Quinaldine conversion. A 478 bp fragment that on pAL1 represents an intergenic region showed 100 % sequence identity in all isolates harbouring a pAL1-like plasmid, suggesting horizontal dissemination of the linear plasmid among the genus Arthrobacter.
Ryo Kato - One of the best experts on this subject based on the ideXlab platform.
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a hydrogen storing Quinaldine polymer nickel electrodeposition assisted hydrogenation and subsequent hydrogen evolution
Polymer International, 2017Co-Authors: Ryo Kato, Takahiro Oya, Yuma Shimazaki, Kenichi Oyaizu, Hiroyuki NishideAbstract:Quinaldine-substituted poly(acrylic acid) (PQD) and its hydrogenated 1,2,3,4-tetrahydroQuinaldine derivative (PHQD) were prepared, and a cycle of hydrogen fixing and hydrogen evolution in and from the polymer, respectively, is described. A PQD layer coated on a carbon substrate was electrochemically reduced or hydrogenated using water as a hydrogen source, accompanied by the electrodeposition of nickel microparticles in the polymer layer, to convert PQD to PHQD. The conversion efficiency was enhanced by coating PQD on the substrate as a scaffold of nickel electrodeposition, in comparison with that of Quinaldine and PQD dissolved in the electrolyte. The formed PHQD evolved hydrogen by simply warming it in water containing an iridium complex catalyst. Hydrogen fixing and evolution under mild conditions could suggest a new system of hydrogen carriers. © 2017 Society of Chemical Industry
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A hydrogen‐storing Quinaldine polymer: nickel‐electrodeposition‐assisted hydrogenation and subsequent hydrogen evolution
Polymer International, 2017Co-Authors: Ryo Kato, Takahiro Oya, Yuma Shimazaki, Kenichi Oyaizu, Hiroyuki NishideAbstract:Quinaldine-substituted poly(acrylic acid) (PQD) and its hydrogenated 1,2,3,4-tetrahydroQuinaldine derivative (PHQD) were prepared, and a cycle of hydrogen fixing and hydrogen evolution in and from the polymer, respectively, is described. A PQD layer coated on a carbon substrate was electrochemically reduced or hydrogenated using water as a hydrogen source, accompanied by the electrodeposition of nickel microparticles in the polymer layer, to convert PQD to PHQD. The conversion efficiency was enhanced by coating PQD on the substrate as a scaffold of nickel electrodeposition, in comparison with that of Quinaldine and PQD dissolved in the electrolyte. The formed PHQD evolved hydrogen by simply warming it in water containing an iridium complex catalyst. Hydrogen fixing and evolution under mild conditions could suggest a new system of hydrogen carriers. © 2017 Society of Chemical Industry
