keyword
MENU ▼
Read by QxMD icon Read
search

Keto

keyword
https://www.readbyqxmd.com/read/28330344/short-time-dynamics-and-decay-mechanism-of-2-1h-pyridinone-upon-excitation-to-the-light-absorbing-s4-2-1
#1
Teng-Shuo Zhang, Jia-Dan Xue, Xuming Zheng, Bin-Bin Xie, Wei-Hai Fang
The excited-state structural dynamics and the decay mechanism of 2(1H)-pyridinone (NHP) after excitation to the S4(2(1)ππ(*)) light-absorbing state were studied using resonance Raman spectroscopy and complete-active space self-consistent field (CASSCF) calculations. The B-band absorption cross-section and the corresponding absolute resonance Raman cross-sections were simulated using a simple model based on time-dependent wave-packet theory. The geometric structures of the singlet electronic excited states and their curve-crossing points were optimized at the CASSCF level of theory...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28329912/structural-and-mechanistic-insights-into-homocysteine-degradation-by-a-mutant-of-methionine-%C3%AE-lyase-based-on-substrate-assisted-catalysis
#2
Dan Sato, Tomoo Shiba, Shunsuke Yunoto, Kazuo Furutani, Mitsuki Fukumoto, Daizou Kudou, Takashi Tamura, Kenji Inagaki, Shigeharu Harada
Methionine γ-lyse (MGL) catalyzes the α, γ-elimination of l-methionine and its derivatives as well as the α, β-elimination of l-cysteine and its derivatives to produce α-keto acids, volatile thiols, and ammonia. The reaction mechanism of MGL has been characterized by enzymological studies using several site-directed mutants. The Pseudomonas putida MGL C116H mutant showed drastically reduced degradation activity toward methionine while retaining activity toward homocysteine. To understand the underlying mechanism and to discern the subtle differences between these substrates, we analyzed the crystal structures of the reaction intermediates...
March 22, 2017: Protein Science: a Publication of the Protein Society
https://www.readbyqxmd.com/read/28328298/the-synthetic-progestin-gestodene-affects-functional-biomarkers-in-neonatal-rat-osteoblasts-through-an-estrogen-receptor-related-mechanism-of-action
#3
Juana Enríquez, Gustavo García, Bertha Herrero, Fernando Larrea
BACKGROUND: Clinical studies have shown that gestodene (GDN), a potent third-generation synthetic progestin, affects bone resorption. However, its mode of action in bone cells is not fully understood. The aim of this study was to establish whether GDN affects bone directly or through its bioconversion to other metabolites with different biological activities. METHODS: In this study, we investigated the effects of GDN and its A-ring reduced metabolites on proliferation, differentiation, and mineralization of calvarial osteoblasts isolated from neonatal rat and their capacity to displace [(3)H]-E2 at ER binding sites...
March 22, 2017: Endocrine Research
https://www.readbyqxmd.com/read/28324888/aldo-keto-reductases-are-biomarkers-of-nrf2-activity-and-are-co-ordinately-overexpressed-in-non-small-cell-lung-cancer
#4
A Kenneth MacLeod, Lourdes Acosta-Jimenez, Philip J Coates, Michael McMahon, Frank A Carey, Tadashi Honda, John D Hayes, Colin J Henderson, C Roland Wolf
No abstract text is available yet for this article.
March 21, 2017: British Journal of Cancer
https://www.readbyqxmd.com/read/28322781/characterization-of-akr1b16-a-novel-mouse-aldo-keto-reductase
#5
Joan Giménez-Dejoz, Susanne Weber, Oleg A Barski, Gabriele Möller, Jerzy Adamski, Xavier Parés, Sergio Porté, Jaume Farrés
Aldo-keto reductases (AKRs) are distributed in three families and multiple subfamilies in mammals. The mouse Akr1b3 gene is clearly orthologous to human AKR1B1, both coding for aldose reductase, and their gene products show similar tissue distribution, regulation by osmotic stress and kinetic properties. In contrast, no unambiguous orthologs of human AKR1B10 and AKR1B15.1 have been identified in rodents. Although two more AKRs, AKR1B7 and AKR1B8, have been identified and characterized in mouse, none of them seems to exhibit properties similar to the human AKRs...
March 17, 2017: Chemico-biological Interactions
https://www.readbyqxmd.com/read/28322568/transition-metal-free-atom-and-step-economic-synthesis-of-aminoketopyrrolizines-from-benzylamine-acylethynylpyrroles-and-acylacetylenes
#6
Lyubov' N Sobenina, Denis N Tomilin, Elena F Sagitova, Igor' A Ushakov, Boris A Trofimov
A concise, atom-economic strategy for the synthesis of pyrrolizines with amino and keto substituents has been developed. It includes the following key steps: (i) the base-catalyzed (K3PO4/DMSO) addition of a benzylamine to 2-acylethynylpyrroles and (ii) noncatalyzed addition of enaminones obtained to the triple bond of acylacetylenes followed by intramolecular cyclization of the intermediate pentadiendiones thus formed to the target 1-(benzylamino)-2-acyl-3-methylenoacylpyrrolizines.
March 21, 2017: Organic Letters
https://www.readbyqxmd.com/read/28322567/access-to-enantiopure-5-7-and-5-7-substituted-cis-decahydroquinolines-enantioselective-synthesis-of-cermizine-b
#7
Alexandre Pinto, Rosa Griera, Elies Molins, Israel Fernández, Joan Bosch, Mercedes Amat
Stereoconvergent cyclocondensation reactions of (R)- or (S)-phenylglycinol with appropriately substituted cyclohexanone-based δ-keto esters are the key steps of short synthetic routes to enantiopure 5-, 7-, and 5,7-substituted cis-decahydroquinolines. The factors governing the stereoselectivity of the cyclocondensation are discussed. The potential of the methodology is illustrated by a protecting-group-free synthesis of the phlegmarine-type Lycopodium alkaloid (-)-cermizine B.
March 21, 2017: Organic Letters
https://www.readbyqxmd.com/read/28320297/selection-of-progesterone-derivatives-specific-to-membrane-progesterone-receptors
#8
A V Polikarpova, A A Maslakova, I S Levina, L E Kulikova, Y V Kuznetsov, A A Guseva, T A Shchelkunova, I V Zavarzin, O V Smirnova
The search of selective agonists and antagonists of membrane progesterone receptors (mPRs) is a starting point for the study of progesterone signal transduction mechanisms mediated by mPRs, distinct from nuclear receptors. According to preliminary data, the ligand affinity for mPRs differs significantly from that for classical nuclear progesterone receptors (nPRs), which might indicate structural differences in the ligand-binding pocket of these proteins. In the present work, we analyzed the affinity of several progesterone derivatives for mPRs of human pancreatic adenocarcinoma BxPC3 cell line that is characterized by a high level of mPR mRNA expression and by the absence of expression of nPR mRNA...
February 2017: Biochemistry. Biokhimii︠a︡
https://www.readbyqxmd.com/read/28320101/effect-of-melilotus-officinalis-extract-on-the-apoptosis-of-brain-tissues-by-altering-cerebral-thrombosis-and-inflammatory-mediators-in-acute-cerebral-ischemia
#9
Gui-Cun Zhao, Yan-Ling Yuan, Feng-Rong Chai, Fa-Jing Ji
Present investigation evaluates the protective effect of Melilotus officinalis (MO) extract on the brain tissues in acute cerebral ischemia. Acute cerebral ischemia was induced by occlusion of carotid artery and rats with cerebral ischemia were treated with MO (100, 250 & 500mg/kg) for the duration of three days. Cerebral ischemia was confirmed by estimating infract volume and neurological deficit score. Moreover biochemical parameters in plasma such as 6-keto-PGF1α and TXB2 and concentration of cytokine, oxidative stress, apoptosis ratio and protein expressions of Bcl2 & Bax were estimated in the brain tissues...
March 17, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28319295/cytosine-radical-cation-a-gas-phase-study-combining-irmpd-spectroscopy-uv-pd-spectroscopy-ion-molecule-reactions-and-theoretical-calculations
#10
Michael Lesslie, John T Lawler, Andy Dang, Joseph A Korn, Daniel Bim, Vincent Steinmetz, Philippe Maitre, Frantisek Turecek, Victor Ryzhov
The radical cation of cytosine (Cyt*+) was generated via dissociative oxidation from a ternary Cu(II) complex in the gas phase. The radical cation was characterized by infrared multiple photon dissociation (IRMPD) spectroscopy in the fingerprint region, UV-VIS photodissociation (UV-PD), ion-molecule reactions, and theoretical calculations (density functional theory and ab initio). The IRMPD experimental spectrum has diagnostic bands for two enol/amino and two keto/amino tautomers of Cyt*+, that were calculated to be among the lowest-energy isomers in concert with a previous work (J...
March 20, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28316823/a-new-solvate-of-afatinib-a-specific-inhibitor-of-the-erbb-family-of-tyrosine-kinases
#11
Matthias Zeller, Gabriel Lima Barros de Araujo, Trev Parker, Amrinder Singh Rai, Stephen R Byrn
Afatinib (systematic name: N-{4-(3-chloro-4-fluoro-anilino)-7-[(tetra-hydro-furan-3-yl)-oxy]quinazolin-6-yl}-4-(di-methyl-amino)-but-2-enamide), is a specific in-hibitor of the ErbB family of tyrosine kinases. The free base form crystallizes from aceto-nitrile as a mixed water-aceto-nitrile solvent, C24H25ClFN5O3·0.25C2H3N·2H2O. It crystallizes with two independent mol-ecules (A and B) in the asymmetric unit of the chiral space group P4212, but exhibits close to perfect pseudo-inversion symmetry, emulating P4/ncc that relates the two mol-ecules to each other...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28302724/genetically-introduced-hydrogen-bond-interactions-reveal-an-asymmetric-charge-distribution-on-the-radical-cation-of-the-special-pair-chlorophyll-p680
#12
Ryo Nagao, Motoki Yamaguchi, Shin Nakamura, Hanayo Ueoka-Nakanishi, Takumi Noguchi
The special-pair chlorophyll (Chl) P680 in photosystem II has an extremely high redox potential (Em) to enable water oxidation in photosynthesis. Significant positive charge localization on one of the Chl constituents, PD1 or PD2, in P680(+) has been proposed to contribute to this high Em To identify the Chl molecule on which the charge is mainly localized, we genetically introduced a hydrogen bond to the 13(1)-keto C=O group of PD1 and PD2 by changing the nearby D1-V157 and D2-V156 residues to His, respectively...
March 16, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28301069/expression-of-akr1b10-as-an-independent-marker-for-poor-prognosis-in-human-oral-squamous-cell-carcinoma
#13
Hui-Hsin Ko, Shih-Lung Cheng, Jang-Jaer Lee, Hsin-Ming Chen, Mark Yen-Ping Kuo, Shih-Jung Cheng
BACKGROUND: Aldo-keto reductase family 1 member B10 (AKR1B10) is implicated in xenobiotic detoxification and has disparate functions in tumorigenesis that are dependent on the cell types. The purpose of this study was to investigate the clinicopathological significance of AKR1B10 as a prognostic marker for oral squamous cell carcinomas (OSCCs). METHODS: AKR1B10 protein expression was analyzed by immunohistochemistry in 77 patients with OSCC. RESULTS: The AKR1B10 labeling score for OSCCs (1...
March 16, 2017: Head & Neck
https://www.readbyqxmd.com/read/28300583/synthesis-of-new-c-25-and-c-26-steroidal-acids-as-potential-ligands-of-the-nuclear-receptors-daf-12-lxr-and-gr
#14
María V Dansey, María C Del Fueyo, Adriana S Veleiro, Pablo H Di Chenna
A new methodology to obtain C-25 and C-26 steroidal acids starting from pregnenolone is described. Construction of the side chain was achieved by applying the Mukaiyama aldol reaction with a non-hydrolytic work-up to isolate the trapped silyl enol ether with higher yields. Using this methodology we synthesized three new steroidal acids as potential ligands of DAF-12, Liver X and Glucocorticoid nuclear receptors and studied their activity in reporter gene assays. Our results show that replacement of the 21-CH3 by a 20-keto group in the side chains of the cholestane scaffold of DAF-12 or Liver X receptors ligands causes the loss of the activity...
March 11, 2017: Steroids
https://www.readbyqxmd.com/read/28299338/antithrombotic-effect-and-mechanism-of-radix-paeoniae-rubra
#15
Pingyao Xie, Lili Cui, Yuan Shan, Wen-Yi Kang
The compounds of Radix Paeoniae Rubra (RPR) were isolated and identified by bioassay-guided method, and antithrombotic effects and mechanism were investigated by the acute blood stasis rat model. The RPR extract was evaluated by APTT, TT, PT, and FIB assays in vitro. Results indicated that RPR extract exhibited the anticoagulant activity. In order to find active compounds, six compounds were isolated and identified, and four compounds, paeoniflorin (Pae), pentagalloylglucose (Pen), albiflorin (Ali), and protocatechuic acid (Pro), exhibited the anticoagulant activity in vitro...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28294261/asymmetric-organocatalytic-synthesis-of-tertiary-azomethyl-alcohols-key-intermediates-towards-azoxy-compounds-and-%C3%AE-hydroxy-%C3%AE-amino-esters
#16
José A Carmona, Gonzalo de Gonzalo, Inmaculada Serrano, Ana M Crespo-Peña, Michal Šimek, David Monge, Rosario Fernández, José M Lassaletta
A series of peracylated glycosamine-derived thioureas have been synthesized and their behavior as bifunctional organocatalysts has been tested in the enantioselective nucleophilic addition of formaldehyde tert-butyl hydrazone to aliphatic α-keto esters for the synthesis of tertiary azomethyl alcohols. Using the 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-β-d-glucosamine derived 3,5-bis-(trifluoromethyl)phenyl thiourea the reaction could be accomplished with high yields (75-98%) and moderate enantioselectivities (50-64% ee)...
March 15, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28292630/a-plate-method-for-rapid-screening-of-ketogulonicigenium-vulgare-mutants-for-enhanced-2-keto-l-gulonic-acid-production
#17
Weichao Yang, Litao Han, Mandlaa Mandlaa, Haihong Zhang, Zhongze Zhang, Hui Xu
A new plate method was developed for rapid screening of Ketogulonicigenium vulgare mutants overproducing 2-keto-l-gulonic acid (2-KLG). The screening methodology took the advantage of the acidity caused by 2-KLG, which changes the color of bromothymol blue (pH indicator) from blue to yellow. Using the proposed method, a mutant, K. vulgare 65, was selected from 20,000 colonies produced by a strain subjected to spaceflight mutagenesis. When co-cultured with Bacillus megaterium 2980 in 20-L fermenters, K. vulgare 65 showed a high conversion rate (94...
February 21, 2017: Brazilian Journal of Microbiology: [publication of the Brazilian Society for Microbiology]
https://www.readbyqxmd.com/read/28286956/nitrosocarbonyl-henry-and-denitration-cascade-synthesis-of-%C3%AE-ketoamides-and-%C3%AE-keto-oximes
#18
Mallu Kesava Reddy, Sumitava Mallik, Isai Ramakrishna, Mahiuddin Baidya
An unprecedented Henry reaction of in situ generated nitrosocarbonyl intermediates and concomitant denitration cascade has been developed. The reaction is catalyzed by organic base at room temperature offering α-ketoamides, a demanding scaffold for drug discovery, in high yields. An alteration of substitution pattern also produced α-keto oximes, a high-value synthon. The protocol features operational simplicity and broad substrate scope.
March 13, 2017: Organic Letters
https://www.readbyqxmd.com/read/28286104/akr1b10-inhibitory-selaginella-tamariscina-extract-and-amentoflavone-decrease-the-growth-of-a549-human-lung-cancer-cells-in-vitro-and-in-vivo
#19
Yu-Jin Jung, Eun Ha Lee, Chang Gun Lee, Ki-Jong Rhee, Woo-Suk Jung, Yongsoo Choi, Cheol-Ho Pan, Kyungsu Kang
ETHNOPHARMACOLOGICAL RELEVANCE: Selaginella tamariscina (P.Beauv.) Spring is a traditional medicinal plant used to treat various human diseases, including cancer, in Asia. The detailed molecular mechanism underlying the anti-cancer effects of this plant and the anti-cancer action of the combinatorial treatment of S. tamariscina and doxorubicin have not yet been investigated. AIM OF THE STUDY: We evaluated the inhibitory activity of S. tamariscina extract (STE) and its major compound, amentoflavone, on human aldo-keto reductase family 1B10 (AKR1B10), which is a detoxification enzyme involved in drug resistance, to evaluate their anti-cancer effects and their potential as adjuvant agents for doxorubicin cancer chemotherapy...
March 9, 2017: Journal of Ethnopharmacology
https://www.readbyqxmd.com/read/28286014/proteomics-based-network-analysis-characterizes-biological-processes-and-pathways-activated-by-preconditioned-mesenchymal-stem-cells-in-cardiac-repair-mechanisms
#20
Dario Di Silvestre, Francesca Brambilla, Giovanni Scardoni, Pietro Brunetti, Sara Motta, Marco Matteucci, Carlo Laudanna, Fabio A Recchia, Vincenzo Lionetti, Pierluigi Mauri
BACKGROUND: We have demonstrated that intramyocardial delivery of human mesenchymal stem cells preconditioned with a hyaluronan mixed ester of butyric and retinoic acid (MSCp(+)) is more effective in preventing the decay of regional myocardial contractility in a swine model of myocardial infarction (MI). However, the understanding of the role of MSCp(+) in proteomic remodeling of cardiac infarcted tissue is not complete. We therefore sought to perform a comprehensive analysis of the proteome of infarct remote (RZ) and border zone (BZ) of pigs treated with MSCp(+) or unconditioned stem cells...
March 7, 2017: Biochimica et Biophysica Acta
keyword
keyword
52292
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"