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dicarboxylic acid

Teng-Fei Lu, Wei Li, Jie Chen, Fu-Quan Bai, Jian Wang, Ling-Jun He, Hong-Xing Zhang
In this work, we designed three dyes (Ru1, Ru2, and Ru3) by modifying the square-planar quadridentate ligand of the experimental Ru(ii) complex K1, [RuL(trans-NCS)2] with L = dimethyl-6,60-bis(methyl-2-pyridylamino)-2,20-bipyridine-4,40-dicarboxylate, from a theoretical viewpoint. As is known, K1 shows obvious advantages over the famous dye N749 in light absorption ability because of its highly conjugated ancillary ligands. Density functional theory and time-dependent density functional theory methods were used to determine the geometrical structures, electronic structures and absorption spectra of the dye complexes...
October 18, 2016: Physical Chemistry Chemical Physics: PCCP
Jeong Wook Lee, Jongho Yi, Tae Yong Kim, Sol Choi, Jung Ho Ahn, Hyohak Song, Moon-Hee Lee, Sang Yup Lee
Succinic acid (SA) is a four carbon dicarboxylic acid of great industrial interest that can be produced by microbial fermentation. Here we report development of a high-yield homo-SA producing Mannheimia succiniciproducens strain by metabolic engineering. The PALFK strain (ldhA(-), pta(-), ackA(-), fruA(-)) was developed based on optimization of carbon flux towards SA production while minimizing byproducts formation through the integrated application of in silico genome-scale metabolic flux analysis, omics analyses, and reconstruction of central carbon metabolism...
October 13, 2016: Metabolic Engineering
Meng Yang, Jinshao Ye, Huaming Qin, Yan Long, Yi Li
Perfluorooctanoic acid (PFOA) has received an increasing attention in the agricultural and food industries due to its risk to human health. To facilitate the development of novel biomarkers of Escherichia coli against PFOA through multi-omics technologies, and to reveal the resistance mechanism of E. coli against PFOA at protein levels, the interactions among pollutant stress, protein expression and cell metabolism was investigated by using iTRAQ-based quantitative proteomic analysis. The results revealed that the 63 up-regulated proteins mainly involved in tricarboxylic acid cycle, glyoxylate and dicarboxylate metabolism and fatty acid biosynthesis, whereas, the 69 down-regulated proteins related to oxidative phosphorylation, pyruvate metabolism and the cell cycle-caulobacter pathway, were also associated with the increase of membrane permeability, excessive expenditure of ATP, disruption of fatty acid biosynthesis under PFOA stress...
October 11, 2016: Environmental Pollution
Scott W Krabbe, Vincent S Chan, Thaddeus S Franczyk, Shashank Shekhar, José G Napolitano, Carmina A Presto, Justin A Simanis
A Cu-catalyzed synthesis of amides from alcohols and secondary amines using the oxygen in air as the terminal oxidant has been developed. The methodology is operationally simple requiring no high pressure equipment or potentially explosive O2 balloons. The commercially available, non-precious metal catalyst, Cu(phen)Cl2, in conjunction with di-tert-butyl hydrazine dicarboxylate and an inorganic base provides a variety of benzamides in moderate to excellent yields. The pKa of amine conjugate acid and electronics of alcohol were shown to impact the selection of base for optimal reactivity...
October 14, 2016: Journal of Organic Chemistry
Ei-Ichi Negishi, Shiqing Xu, Haijun Li, Masato Komiyama, Akimichi Oda
A one-step homologation protocol for the synthesis of natural products containing deoxypropionate motif is described by the combination of ZACA-Pd-catalyzed vinylation and ZACA-oxidation reaction. Contrastive to most other synthetic strategies used to date that require 3-6 steps per deoxypropionate unit due to the functional-group interconversions, our one-step homologation strategy promises to provide a general and more efficient synthetic route toward deoxypropionate natural products as exemplified by significant improvements in the syntheses of intermediates and/or final products of mycolipenic acid 1 and its analogue 2, (-)-rasfonin, and syn- and anti-dicarboxylic acids 5 and 6...
October 14, 2016: Chemistry: a European Journal
Ling Liu, Yu Han, Junhai Xiao, Li Li, Liangdong Guo, Xuejun Jiang, Lingyi Kong, Yongsheng Che
Chlorotheolides A (1) and B (2), two new spiroketals possessing the unique [4,7]methanochromene and dispiro-trione skeletons, respectively, and their putative biosynthetic precursors, 1-undecen-2,3-dicarboxylic acid (3) and maldoxin (4), were isolated from the solid substrate fermentation of the plant endophytic fungus Pestalotiopsis theae (N635). Their structures were elucidated based on NMR spectroscopic data and electronic circular dichroism calculations. Biogenetically, compounds 1 and 2 could be generated from the co-isolated 3 and 4 via Diels-Alder reactions...
October 12, 2016: Journal of Natural Products
Xin Wang, Alexandros Lamprou, Frantisek Svec, Yu Bai, Huwei Liu
A new approach to the preparation of enantioselective porous polymer monolithic columns with incorporated chiral metal-organic framework for nano-liquid chromatography has been developed. While no enantioseparation was achieved with monolithic poly(4-vinylpyridine-co-ethylene dimethacrylate) column, excellent separations of both enantiomers of (±)-methyl phenyl sulfoxide were achieved with its counterpart prepared after admixing the metal-organic framework [Zn2 (benzene dicarboxylate)(l-lactic acid)(dmf)](DMF), which is synthesized from zinc nitrate, l-lactic acid, and benzene dicarboxylic acid in the polymerization mixture...
October 12, 2016: Journal of Separation Science
Meredith Meyer, Attila D Kovács, David A Pearce
Infantile CLN1 disease, also known as infantile neuronal ceroid lipofuscinosis, is a fatal childhood neurodegenerative disorder caused by mutations in the CLN1 gene. CLN1 encodes a soluble lysosomal enzyme, palmitoyl protein thioesterase 1 (PPT1), and it is still unclear why neurons are selectively vulnerable to the loss of PPT1 enzyme activity in infantile CLN1 disease. To examine the effects of PPT1 deficiency on several well-defined neuronal signaling and cell death pathways, different toxic insults were applied in cerebellar granule neuron cultures prepared from wild type (WT) and palmitoyl protein thioesterase 1-deficient (Ppt1 (-/-) ) mice, a model of infantile CLN1 disease...
October 8, 2016: Metabolic Brain Disease
Kang Shen, Ling Qin, He-Gen Zheng
Three new coordination polymers have been synthesized based on three linear pyridine ligands with different side chains and one flexible V-shaped dicarboxylate co-ligand: {[Co(L1)0.5(sdb)]}n (1), {[Co(L2)0.5(sdb)]·1.5H2O}n (2) and {[Co(L3)0.5(sdb)]·2DMF}n (3) (L1 = E,E-2,5-dioctyloxy-1,4-bis-[2-pyridin-vinyl]-benzene; L2 = E,E-2,5-dibutoxy-1,4-bis-[2-pyridin-vinyl]-benzene; L3 = E,E-2,5-dimethoxy-1,4-bis-[2-pyridin-vinyl]-benzene; H2sdb = 4,4'-sulfonyldibenzoic acid). Complexes 1-3 are 4-connected sql nets with a point symbol of {4(4)·6(2)}...
October 18, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Nan Xu, Chao Ye, Xiulai Chen, Jia Liu, Liming Liu, Jian Chen
Candida glabrata CCTCC M202019 as an industrial yeast strain that is widely used to produce α-oxocarboxylic acid. Strain M202019 has been proven to have a higher pyruvate-producing capacity than the reference strain CBS138. To characterize the genotype of the M202019 strain, we generated a draft sequence of its genome, which has a size of 12.1 Mbp and a GC content of 38.47%. Evidence accumulated during genome annotation suggests that strain M202019 has strong capacities for glucose transport and pyruvate biosynthesis, defects in pyruvate catabolism, as well as variations in genes involved in nutrient and dicarboxylic acid transport, oxidative phosphorylation, and other relevant aspects of carbon metabolism, which might promote pyruvate accumulation...
October 7, 2016: Scientific Reports
Lei Rao, Yongtao Wang, Fang Chen, Xiaojun Liao
The inactivation effects of high pressure CO2 + nisin (simultaneous treatment of HPCD and nisin, HPCD + nisin), HPCD→nisin (HPCD was followed by nisin), and nisin→HPCD (nisin was followed by HPCD) treatments on Bacillus subtilis spores in aqueous solutions were compared. The spores were treated by HPCD at 6.5 or 20 MPa, 84-86°C and 0-30 min, and the concentration of nisin was 0.02%. Treated spores were examined for the viability, the permeability of inner membrane (IM) using flow cytometry method and pyridine-2, 6-dicarboxylic acid (DPA) release, and structural damage by transmission electron microscopy...
2016: Frontiers in Microbiology
Dianne J Xiao, Julia Oktawiec, Phillip J Milner, Jeffrey R Long
Metal-organic frameworks are a new class of heterogeneous catalysts in which molecular-level control over both the immediate and long-range chemical environment surrounding a catalytic center can be readily achieved. Here, the oxidation of cyclohexane to cyclohexanol and cyclohexanone is used as a model reaction to investigate the effect of a hydrophobic pore environment on product selectivity and catalyst stability in a series of iron-based frameworks. Specifically, expanded analogues of Fe2(dobdc) (dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate) were synthesized and evaluated, including the biphenyl derivative Fe2(dobpdc) (H4dobpdc = 4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid), the terphenyl derivative Fe2(dotpdc) (H4dotpdc = 4,4''-dihydroxy-[1,1':4',1''-terphenyl]-3,3''-dicarboxylic acid), and three modified terphenyl derivatives in which the central ring is replaced with tetrafluoro-, tetramethyl-, or di-tert-butylaryl groups...
October 5, 2016: Journal of the American Chemical Society
Wenqin Bai, Yi-Shu Tai, Jingyu Wang, Jilong Wang, Pooja Jambunathan, Kevin J Fox, Kechun Zhang
Dicarboxylic acids are attractive biosynthetic targets due to their broad applications and their challenging manufacturing process from fossil fuel feedstock. Mesaconate is a branched, unsaturated dicarboxylic acid that can be used as a co-monomer to produce hydrogels and fire-retardant materials. In this study, we engineered nonphosphorylative metabolism to produce mesaconate from d-xylose and l-arabinose. This nonphosphorylative metabolism is orthogonal to the intrinsic pentose metabolism in Escherichia coli and has fewer enzymatic steps and a higher theoretical yield to TCA cycle intermediates than the pentose phosphate pathway...
September 30, 2016: Metabolic Engineering
Liwen Mu, Tuo Ji, Long Chen, Nitin Mehra, Yijun Shi, Jiahua Zhu
Phonon transfer is greatly scattered in traditional polymer composites due to the unpaired phonon frequency at polymer/filler interface. A key innovation of this work is to build continuous crystal network by self-organization and utilize it as "thermal highway" that circumvents the long-existing interfacial thermal barrier issue in traditional composites. By tuning the molecular diffusion rate of dicarboxylic acids (oxalic acid, malonic acid and succinic acid), different crystal structures including skeletal, dendrite, diffusion limited aggregates and spherulite were synthesized in PVA film...
October 3, 2016: ACS Applied Materials & Interfaces
Amalie Ribel-Madsen, Rasmus Ribel-Madsen, Charlotte Brøns, Christopher B Newgard, Allan A Vaag, Lars I Hellgren
We hypothesized that an increased, incomplete fatty acid beta-oxidation in mitochondria could be part of the metabolic events leading to insulin resistance and thereby an increased type 2 diabetes risk in low birth weight (LBW) compared with normal birth weight (NBW) individuals. Therefore, we measured fasting plasma levels of 45 acylcarnitine species in 18 LBW and 25 NBW men after an isocaloric control diet and a 5-day high-fat, high-calorie diet. We demonstrated that LBW men had higher C2 and C4-OH levels after the control diet compared with NBW men, indicating an increased fatty acid beta-oxidation relative to the tricarboxylic acid cycle flux...
October 2016: Physiological Reports
Mark A Lashley, Alexander S Ivanov, Vyacheslav S Bryantsev, Sheng Dai, Robert D Hancock
Studies of the complexation of new promising ligands with uranyl (UO2(2+)) and other seawater cations can aid the development of more efficient, selective, and robust sorbents for the recovery of uranium from seawater. In this work, we propose that the ligand design principles based on structural preorganization can be successfully applied to obtain a dramatic enhancement in UO2(2+) ion binding affinity and selectivity. This concept is exemplified through the investigation of the complexes of UO2(2+), VO2(+), and VO(2+) with the highly preorganized ligand 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) using a combination of fluorescence and absorbance techniques, along with density functional theory (DFT) calculations...
October 17, 2016: Inorganic Chemistry
Syamantak Roy, Arpan Hazra, Arkamita Bandyopadhyay, Devraj Raut, P Lakshmi Madhuri, D S Shankar Rao, Upadrasta Ramamurty, Swapan Kumar Pati, S Krishna Prasad, Tapas Kumar Maji
We report the design, synthesis, detailed characterization, and analysis of a new multifunctional π-conjugated bola-amphiphilic chromophore: oligo-(p-phenyleneethynylene)dicarboxylic acid with dialkoxyoctadecyl side chains (OPE-C18-1). OPE-C18-1 shows two polymorphs at 123 K (OPE-C18-1') and 373 K (OPE-C18-1″), whose crystal structures were characterized via single crystal X-ray diffraction. OPE-C18-1 also exhibits thermotropic liquid crystalline property revealing a columnar phase. The inherent π-conjugation of OPE-C18-1 imparts luminescence to the system...
October 3, 2016: Journal of Physical Chemistry Letters
Ran Zhao, Lei Mei, Lin Wang, Zhi-Fang Chai, Wei-Qun Shi
By employing a multidentate ligand, 2,2'-bipyridine-5,5'-dicarboxylic acid (H2bpdc), with both O-donors and N-donors, five uranyl-Cu(II)/Zn(II) heterometallic coordination polymers, (UO2)Cu(μ4-bpdc)(μ3-bpdc) (1-Cu), (UO2)Zn(μ4-bpdc)(μ3-bpdc) (1'-Zn), (UO2)CuCl(μ3-bpdc)(μ2-Hbpdc)(H2O) (2-Cu), (UO2)2Cu2Cl2(μ3-bpdc)2(μ2-Hbpdc)2(H2O)3·2H2O (2-Cu'), and (UO2)2Zn(μ3-SO4)(μ4-bpdc)(μ3-bpdc)(H2O)3 (3-Zn), were prepared under hydrothermal conditions. Thermal stability and luminescent properties of 1-Cu, 1'-Zn, 2-Cu, and 3-Zn were also investigated...
October 17, 2016: Inorganic Chemistry
Kei Muto, Taito Hatakeyama, Kenichiro Itami, Junichiro Yamaguchi
The first palladium-catalyzed decarbonylative coupling of phenyl 2-azinecarboxylates and arylboronic acids is presented. The key for the development of this decarbonylative coupling is the use of Pd/dcype as a catalyst. A wide range of 2-azinecarboxylates can undergo the present coupling reaction to afford 2-arylazines. By combination with previously reported nickel-catalyzed decarbonylative coupling, we achieved a chemoselective sequential decarbonylative coupling of pyridine dicarboxylate to synthesize 2,4-diarylpyridine...
October 7, 2016: Organic Letters
Ya-Guang Sun, Yi-Ning Sun, Li-Xin You, Yi-Nan Liu, Fu Ding, Bao-Yi Ren, Gang Xiong, Valerian Dragutan, Ileana Dragutan
New cytotoxic, mononuclear Pt and Pd coordination complexes featuring the planar, multi-donor ligand (2,3-f)pyrazino(1,10)phenanthroline-2,3-dicarboxylic acid (H2PPDA) have been synthesized under hydrothermal conditions (in water, at high temperature and pressure) and fully characterized. The complexes were proven to be isostructural by applying the single-crystal X-ray diffraction technique. UV-Vis and fluorescence spectroscopy investigations on their interaction with fish sperm DNA revealed a considerable binding capacity while gel electrophoresis provided evidence in favor of cleavage of pBR322 plasmid DNA...
September 14, 2016: Journal of Inorganic Biochemistry
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