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https://www.readbyqxmd.com/read/28933277/identification-of-an-interaction-between-a-histidine-kinase-response-regulator-hybrid-protein-and-2-keto-3-deoxy-d-manno-octulosonate-8-phosphate-synthase-in-gluconobacter-oxydans
#1
Cuijuan Yuan, Yangchen Lin, Yushu Ma, Dongzhi Wei
The histidine kinase response regulator hybrid protein was identified as a member of two-component signaling systems in Gluconobacter oxydans by gene annotation, but the function of this protein remains unknown. In this research, its specific interaction with a 2-keto-3-deoxy-D-manno-octulosonate-8-phosphate synthase was screened by yeast two-hybrid assay. The interaction between the two proteins was further identified by GST pull-down assay and bimolecular fluorescence complementation assay in vitro and in vivo, respectively...
September 19, 2017: Protein and Peptide Letters
https://www.readbyqxmd.com/read/28932443/crystal-structures-of-three-1-4-4-bromo-but-oxy-phen-yl-chalcone-derivatives-e-1-4-4-bromo-but-oxy-phen-yl-3-phenyl-prop-2-en-1-one-e-1-4-4-bromo-but-oxy-phen-yl-3-4-meth-oxy-phen-yl-prop-2-en-1-one-and-e-1-4-4-bromo-but-oxy-phen-yl-3-3-4-di-meth-oxy-phen-yl
#2
Gunasekaran Maragatham, Sivasamy Selvarani, Perumal Rajakumar, Srinivasakannan Lakshmi
The crystal structures of three chalcones with a bromo-substituted but-oxy side chain, viz. (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-phenyl-prop-2-en-1-one, C19H19BrO2, (I), (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(4-meth-oxy-phen-yl)prop-2-en-1-one, C20H21BrO3, (II), and (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one, C21H23BrO4, (III), are reported. In all mol-ecules, the conformation of the keto group with respect to the olefinic bond is s-cis. Mol-ecules of (I) and (II) are nearly planar, while mol-ecule (III) is not planar...
July 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28932441/structure-of-equilenin-at-100%C3%A2-k-an-estrone-related-steroid
#3
Christopher S Frampton, David D MacNicol
The structure of the estrone-related steroid, Equilenin, C18H18O2 (systematic name 3-hy-droxy-13-methyl-11,12,13,14,15,16-hexa-hydro-cyclo-penta-[a]phen-anthren-17-one), has been determined at 100 K. The crystals are ortho-rhom-bic, P212121, and the absolute structure of the mol-ecule in the crystal has been determined by resonant scattering [Flack parameter = -0.05 (4)]. The C atoms of the A and B rings are almost coplanar, with an r.m.s. deviation from planarity of 0.0104 Å. The C ring has a sofa conformation, while the D ring has an envelope conformation with the methine C atom as the flap...
July 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28929765/direct-spirocyclization-from-keto-sulfonamides-an-approach-to-azaspiro-compounds
#4
Frédéric Beltran, Indira Fabre, Ilaria Ciofini, Laurence Miesch
Spontaneous spirocyclization of keto-sulfonamides via ynamides through a one-pot process is presented. Push-pull ynamides were obtained through Michael addition/elimination without Cu. The obtained azaspiro compounds are building blocks for indole alkaloids. Theoretical studies provide insights into the mechanism of the formal Conia-ene reaction.
September 20, 2017: Organic Letters
https://www.readbyqxmd.com/read/28929377/opposing-roles-of-the-aldo-keto-reductases-akr1b1-and-akr1b10-in-colorectal-cancer
#5
Betul Taskoparan, Esin Gulce Seza, Secil Demirkol, Sinem Tuncer, Milan Stefek, Ali Osmay Gure, Sreeparna Banerjee
PURPOSE: Aldo-keto reductases (including AKR1B1 and AKR1B10) constitute a family of oxidoreductases that have been implicated in the pathophysiology of diabetes and cancer, including colorectal cancer (CRC). Available data indicate that, despite their similarities in structure and enzymatic functions, their roles in CRC may be divergent. Here, we aimed to determine the expression and functional implications of AKR1B1 and AKR1B10 in CRC. METHODS: AKR1B1 and AKR1B10 gene expression levels were analyzed using publicly available microarray data and ex vivo CRC-derived cDNA samples...
September 19, 2017: Cellular Oncology (Dordrecht)
https://www.readbyqxmd.com/read/28926911/enhanced-biosynthesis-of-3-4-dihydroxybutyric-acid-by-engineered-escherichia-coli-in-a-dual-substrate-system
#6
Haijun Gao, Yu Gao, Runan Dong
3,4-Dihydroxybutyric acid (3,4-DHBA), a versatile platform four carbon (C4) chemical, can be used as a precursor in the production of many commercially important chemicals. Here, a dual-substrate biosynthesis system was developed for 3,4-DHBA production via a synthetic pathway established in an engineered Escherichia coli, and using xylose as a synthetic substrate and glucose as a cell growth substrate. The deletion of genes xylA, yjhH and yagE and others encoding for alcohol dehydrogenases in E. coli is essential for the production of 3,4-DHBA...
September 5, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28925893/big-data-analyses-for-continuous-evaluation-of-pharmacotherapy-a-proof-of-principle-with-doxapram-in-preterm-infants
#7
Robert Flint, Willem van Weteringen, Swantje Völler, Jarinda A Poppe, Birgit Cp Koch, Ronald de Groot, Dick Tibboel, Catherijne Aj Knibbe, Irwin Km Reiss, Sinno Hp Simons
BACKGROUND: Drug effect evaluation is often based on subjective interpretation of a selection of patient data. Continuous analyses of high frequency patient monitor data are a valuable source to measure drug effects. However, these have not yet been fully explored in clinical care. We aim to evaluate the usefulness and applicability of high frequency physiological data for analyses of pharmacotherapy. METHODS: As a proof of principle, the effects of doxapram, a respiratory stimulant, on the oxygenation in preterm infants were studied...
September 18, 2017: Current Pharmaceutical Design
https://www.readbyqxmd.com/read/28925022/organocatalytic-enantioselective-protonation-for-photoreduction-of-activated-ketones-and-ketimines-induced-by-visible-light
#8
Lu Lin, Xiangbin Bai, Xinyi Ye, Xiaowei Zhao, Choon-Hong Tan, Zhiyong Jiang
The first catalytic asymmetric photoreduction of 1,2-diketones and α-keto ketimines under visible light irradiation is reported. A transition-metal-free synergistic catalysis platform harnessing dicyanopyrazine-derived chromophore (DPZ) as the photoredox catalyst and a non-covalent chiral organocatalyst is effective for these transformations. With the flexible use of a chiral Brønsted acid or base in H+ transfer interchange to control the elusive enantioselective protonation, a variety of chiral α-hydroxy ketones and α-amino ketones were obtained with high yields and enantioselectivities...
September 19, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28922901/localization-of-an-aldo-keto-reductase-akr2e4-in-the-silkworm-bombyx-mori-lepidoptera-bombycidae
#9
K Yamamoto, Y Ozakiya, T Uno
The aldo-keto reductase AKR2E4 reduces 3-dehydroecdysone to ecdysone in the silkworm Bombyx mori L. In this study, a quantitative polymerase chain reaction analysis revealed that the level of AKR2E4 mRNA was higher in the testes than in other tissues, and a western immunoblot analysis revealed that the AKR2E4 content in the testes was stage-specific from the fifth larval instar to the pupal stage. Immunohistochemical analysis showed that the AKR2E4 protein was present in cyst cells associated with sperm cells and spermatocytes...
September 1, 2017: Journal of Insect Science
https://www.readbyqxmd.com/read/28920604/a-ratiometric-fluorescent-ph-probe-based-on-keto-enol-tautomerization-for-imaging-of-living-cells-in-extreme-acidity
#10
Zong-Xuan Tong, Wei Liu, Hui Huang, Hong-Zong Chen, Xian-Jun Liu, Yong-Qing Kuang, Jian-Hui Jiang
6-(Diethylamino)-2,3-dihydro-1H-xanthene-4-carbaldehyde (DDXC), a reported synthetic intermediate for near-infrared fluorescent dyes, was developed into a fluorescent pH probe for extreme acidity. The unique sensing mechanism of DDXC for pH is based on the reversible protonation of the carbonyl oxygen followed by keto-enol tautomerization. The probe displays a linear ratiometric fluorescence response (I512/I580) to H(+) over the extremely acidic range of pH 2.0-4.0 with a pKa of 3.11, and features high fluorescence quantum yield (Φ = 0...
September 18, 2017: Analyst
https://www.readbyqxmd.com/read/28915943/derivatization-enhanced-separation-and-sensitivity-of-long-chain-free-fatty-acids-application-to-asthma-using-targeted-and-non-targeted-liquid-chromatography-mass-spectrometry-approach
#11
Xiqing Bian, Baoqing Sun, Peiyan Zheng, Na Li, Jian-Lin Wu
Long chain-free fatty acids (LCFFAs) play pivotal roles in various physiological functions, like inflammation, insulin resistance, hypertension, immune cell behavior and other biological activities. However, the detection is obstructed by the low contents, structural diversity, high structural similarity, and matrix interference. Herein, a fast cholamine-derivatization, within 1 min at room temperature, coupled with liquid chromatography-mass spectrometry (LC-MS) approach was developed to determine LCFFAs in complex samples...
October 9, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28915484/spontaneous-vesicle-formation-and-vesicle-to-micelle-transition-of-sodium-2-ketooctanate-in-water
#12
Huifang Xu, Na Du, Yawen Song, Shue Song, Wanguo Hou
Single-tailed short-chain alkyl keto-acids/salts, a class of fatty acid/salt derivatives, such as sodium 2-ketooctanate (KOCOONa), are a kind of weakly acid/salt type amphiphiles and plausible prebiotic molecules, and the current understanding of their aggregation behavior in aqueous solutions is still limited. Herein, the aggregation behavior of KOCOONa in aqueous solution was studied by changing its concentration (C), using equilibrium surface tension, conductivity, and fluorescence measurements. The aggregates formed were characterized using freeze-fracture and cryogenic transmission electron microscopy, dynamic light scattering, atomic force microscopy, and confocal laser scanning microscopy...
September 7, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28914947/singlet-oxygen-mediated-one-pot-chemoselective-peptide-peptide-ligation
#13
Eirini Antonatou, Yentl Verleysen, Annemieke Madder
We here describe a furan oxidation based site-specific chemical ligation approach using unprotected peptide segments. This approach involves two steps: after photooxidation of a furan-containing peptide, ligation is achieved by reaction of the unmasked keto-enal with C- or N-terminal α-nucleophilic moieties of the second peptide such as hydrazine or hydrazide to form a pyridazinium or pyrrolidinone linkage respectively.
September 15, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28910104/reaction-of-silyllithium-%C3%AE-keto-n-tert-butanesulfinyl-imidates-and-aldehydes-for-asymmetric-synthesis-of-%C3%AE-substituted-%C3%AE-silyloxy-%C3%AE-hydroxy-acid-derivatives
#14
Wei Huang, Hui Liu, Yan-Jun Xu, Chong-Dao Lu
A single-flask reaction of silyllithium, α-keto N-tert-butanesulfinyl imidates and aldehydes has been developed for diastereoselective synthesis of α,β-dihydroxy acid derivatives. In this reaction, nucleophilic addition of silyllithium to chiral α-keto imidates followed by silyl migration forms chiral aza-enolates, which react diastereoselectively with aldehydes. Subsequent [1,4]-O to O silyl migration affords α-substituted β-(silyoxy)-α-hydroxy imidates.
September 14, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28902215/one-pot-synthesis-of-2-3-difunctionalized-indoles-via-rh-iii-catalyzed-carbenoid-insertion-c-h-activation-cyclization
#15
Honggui Lv, Jingjing Shi, Bo Wu, Yujuan Guo, Junjun Huang, Wei Yi
Reported herein is the first Rh(iii)-catalyzed carbenoid insertion C-H activation/cyclization of N-arylureas and α-diazo β-keto esters. The redox-neutral reaction has the following features: good to excellent yields, broad substrate/functional group tolerance, exclusive regioselectivity, and no need for additional oxidants or additives, which render this methodology as a more efficient and versatile alternative to the existing methods for the synthesis of 2,3-difunctionalized indoles.
September 13, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28901445/identification-of-genes-associated-with-castration%C3%A2-resistant-prostate-cancer-by-gene-expression-profile-analysis
#16
Chui Guo Huang, Feng Xi Li, Song Pan, Chang Bao Xu, Jun Qiang Dai, Xing Hua Zhao
Prostate cancer (CaP) is a serious and common genital tumor. Generally, men with metastatic CaP can easily develop castration‑resistant prostate cancer (CRPC). However, the pathogenesis and tumorigenic pathways of CRPC remain to be elucidated. The present study performed a comprehensive analysis on the gene expression profile of CRPC in order to determine the pathogenesis and tumorigenic of CRPC. The GSE33316 microarray, which consisted of 5 non‑castrated samples and 5 castrated samples, was downloaded from the gene expression omnibus database...
September 13, 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28899484/rational-design-of-kluyveromyces-marxianus-zjb14056-aldo-keto-reductase-kmakr-to-enhance-diastereoselectivity-and-activity
#17
Ya-Jun Wang, Bin-Bin Ying, Wei Shen, Ren-Chao Zheng, Yu-Guo Zheng
t-Butyl 6-cyano-(3R,5R)-dihydroxyhexanoate ((3R,5R)-1b) is a valuable chiral synthon of atorvastatin calcium. A novel NADPH-specific aldo-keto reductase (AKR) was identified from a thermotolerant yeast Kluyveromyces marxianus ZJB14056 by genome database mining, displaying t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate ((5R)-1a) reducing activity and moderate diastereoselectivity (dep∼80.5%). Molecular homology modeling and docking studies demonstrated that the side chain of Trp297 blocks binding of (5R)-1a to KmAKR...
December 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28895472/aldo-keto-reductase-akr-1c3-inhibitors-a-patent-review
#18
Trevor M Penning
AKR1C3 is a drug target in hormonal and hormonal independent malignancies and acts as a major peripheral 17β -hydroxysteroid dehydrogenase to yield the potent androgens testosterone and dihydrotestosterone, and as a prostaglandin (PG) F synthase to produce proliferative ligands for the PG FP receptor. AKR1C3 inhibitors may have distinct advantages over existing therapeutics for the treatment of castration resistant prostate cancer, breast cancer and acute myeloid leukemia. Area Covered: This article reviews the patent literature on AKR1C3 inhibitors using SciFinder which identified inhibitors in the following chemical classes: N-phenylsulfonyl-indoles, N-(benzimidazoylylcarbonyl)- N-(indoylylcarbonyl)- and N-(pyridinepyrrolyl)- piperidines, N-benzimidazoles and N-benzindoles, repurposed nonsteroidal antiinflammatory drugs (indole acetic acids, N-phenylanthranilates and aryl propionic acids), isoquinolines, and nitrogen and sulfur substituted estrenes...
September 12, 2017: Expert Opinion on Therapeutic Patents
https://www.readbyqxmd.com/read/28895083/influence-of-transition-metal-cationization-versus-sodium-cationization-and-protonation-on-the-gas-phase-tautomeric-conformations-and-stability-of-uracil-application-to-ura-cu-and-ura-ag
#19
T E Akinyemi, R R Wu, Y-W Nei, N A Cunningham, H A Roy, J D Steill, G Berden, J Oomens, M T Rodgers
The gas-phase conformations of transition metal cation-uracil complexes, [Ura+Cu](+) and [Ura+Ag](+), were examined via infrared multiple photon dissociation (IRMPD) action spectroscopy and theoretical calculations. IRMPD action spectra were measured over the IR fingerprint and hydrogen-stretching regions. Structures and linear IR spectra of the stable tautomeric conformations of these complexes were initially determined at the B3LYP/6-31G(d) level. The four most stable structures computed were also examined at the B3LYP/def2-TZVPPD level to improve the accuracy of the predicted IR spectra...
September 11, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28891567/enantioselective-electrophilic-cyanation-of-%C3%AE-keto-amides-catalysed-by-a-cinchona-organocatalyst
#20
Pran Gopal Karmaker, Jiashen Qiu, Di Wu, Mengmeng Reng, Zhuo Yang, Hongquan Yin, Fu-Xue Chen
An operationally simple protocol for the enantioselective electrophilic α-cyanation of β-keto amides catalyzed by cinchona-derived catalysts has been demonstrated. The resulting products could be obtained with good to high enantioselectivities (up to 88% ee) and with excellent yields (up to 94%) by employing the mild active 4-acetylphenyl cyanate as the cationic cyano source in the catalytic asymmetric α-cyanation reaction.
September 11, 2017: Organic & Biomolecular Chemistry
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