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Michael R Luzung, Darryl D Dixon, Adrian Ortiz, Carlos A Guerrero, Sloan Ayers, Jeanne Ho, Michael A Schmidt, Neil A Strotman, Martin D Eastgate
An addition of organozinc nucleophiles to N-acyl activated quinolines and isoquinolines is described. Simple transmetalla-tion with the corresponding Grignard reagents using ZnCl2 forms organozinc compounds which are functional group tolerant and stable to reactive acyl chloride reagents for extended periods. A wide variety of substrates which include reactive elec-tron-withdrawing groups are well tolerated to form 2-substituted dihydroquinolines and dihydroisoquinolines. This method-ology has been applied towards an improved synthetic route of uncialamycin and its analogs...
August 15, 2017: Journal of Organic Chemistry
Weiqi Xue, Tianwei Hao, Hamish R Mackey, Xiling Li, Richard C Chan, Guanghao Chen
Sulfate-rich wastewaters pose a major threat to mainstream wastewater treatment due to the unpreventable production of sulfide and associated shift in functional bacteria. Aerobic granular sludge could mitigate these challenges in view of its high tolerance and resilience against changes in various environmental conditions. This study aims to confirm the feasibility of aerobic granular sludge in the treatment of sulfate containing wastewater, investigate the impact of sulfate on nutrient removal and granulation, and reveal metabolic relationships in the above processes...
August 4, 2017: Water Research
Toru Uyama, Kazuhito Tsuboi, Natsuo Ueda
The HRAS-like suppressor (HRASLS) is a protein family consisting of five members in humans. Despite their discovery as tumor suppressors, we demonstrated that all these proteins are phospholipid-metabolizing enzymes, such as phospholipase A1 /A2 and acyltransferase. We thus proposed to rename HRASLS1-5 as phospholipase A/acyltransferase (PLAAT)-1-5. Notably, PLAATs exhibit N-acyltransferase activity to biosynthesize N-acylated ethanolamine phospholipids, including N-acyl-plasmalogen, which serve as precursors of bioactive N-acylethanolamines...
August 10, 2017: FEBS Letters
Bruna Á Pereira, Alcione V de Bastos, Wystan K O Teixeira, Sidnei Moura E Silva, Alex F C Flores, Darlene C Flores
An elegant, efficient, and highly regioselective approach for the synthesis of novel methyl 5-amino-3-(methylthio)-1-differently substituted-1H-pyrazole-4-carboxylates is reported. The procedure involves the cyclocondensation of [Formula: see text]-oxeketene [Formula: see text]-dimethyl acetal building blocks with different alkyl, aryl, and heterocyclic acid hydrazides. The novel molecules were obtained in good yields and their identities confirmed by NMR and HRMS spectrometry.
August 8, 2017: Molecular Diversity
Gonzalo García-Rojo, Fernando Gámiz, Estíbaliz Ampuero, Daniel Rojas-Espina, Rodrigo Sandoval, Carlos Rozas, Bernardo Morales, Ursula Wyneken, Floria Pancetti
Acylpeptide hydrolase (APEH) is a serine hydrolase that displays two catalytic activities, acting both as an exopeptidase toward short N-acylated peptides and as an endopeptidase toward oxidized peptides or proteins. It has been demonstrated that this enzyme can degrade monomers, dimers, and trimers of the Aβ1-40 peptide in the conditioned media of neuroblastoma cells. In a previous report, we showed that the specific inhibition of this enzyme by the organophosphate molecule dichlorvos (DDVP) triggers an enhancement of long-term potentiation in rat hippocampal slices...
2017: Frontiers in Pharmacology
Carlos Heras, Alejandro Gómez-Palomino, Pedro Romea, Fèlix Urpí, Josep Maria Bofill, Ibério de P R Moreira
Quantum chemical calculations have unveiled the unexpected biradical character of titanium(IV) enolates from N-acyl oxazolidinones and thiazolidinethiones. The electronic structure of these species therefore involves a valence tautomerism consisting of an equilibrium between a closed shell (formally Ti(IV) enolates) and an open shell, biradical, singlet (formally Ti(III) enolates) electronic states, whose origin is to be basically found in changes of the Ti-O distance. Spectroscopic studies of the intermediate species lend support to such a model, which also turns out to be crucial for a better understanding of the overall reactivity of titanium(IV) enolates...
August 7, 2017: Journal of Organic Chemistry
Josiane Fukami, Julia Laura Fernandes Abrantes, Pablo Del Cerro, Marco Antonio Nogueira, Francisco Javier Ollero, Manuel Megías, Mariangela Hungria
Azospirillum brasilense is an important plant-growth promoting bacterium (PGPB) that requires several critical steps for root colonization, including biofilm and exopolysaccharide (EPS) synthesis and cell motility. In several bacteria these mechanisms are mediated by quorum sensing (QS) systems that regulate the expression of specific genes mediated by the autoinducers N-acyl-homoserine lactones (AHLs). We investigated QS mechanisms in strains Ab-V5 and Ab-V6 of A. brasilense, which are broadly used in commercial inoculants in Brazil...
August 5, 2017: Archives of Microbiology
Kotaro Hama, Yuko Fujiwara, Hidetsugu Tabata, Hideyo Takahashi, Kazuaki Yokoyama
Sphingomyelin (ceramide-phosphocholine, CerPCho) is a common sphingolipid in mammalian cells and is composed of phosphorylcholine and ceramide as polar and hydrophobic components, respectively. In this study, a qualitative liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS/MS) analysis is proposed in which CerPCho structures were assigned based on product ion spectra corresponding to sphingosylphosphorylcholine and N-acyl moieties. From MS/MS/MS analysis of CerPCho, we observed product ion spectra of the N-acyl fatty acids as [RCO2](-) ions as well as sphingosylphosphorylcholine...
August 2, 2017: Lipids
Akanksha Rajput, Manoj Kumar
LuxI and LuxR are key factors that drive quorum sensing (QS) in bacteria through secretion and perception of the signaling molecules e.g. N-Acyl homoserine lactones (AHLs). The role of these proteins is well established in Gram-negative bacteria for intercellular communication but remain under-explored in Gram-positive bacteria where QS peptides are majorly responsible for cell-to-cell communication. Therefore, in the present study, we explored conservation, potential function, topological arrangements and evolutionarily aspects of these proteins in Gram-positive bacteria...
August 1, 2017: Scientific Reports
Milind Mohan Naik, Purva Bhangui, Chinmay Bhat
Listeria monocytogenes are Gram-positive well-known emerging food-borne pathogens causing listeriosis in humans. In the present study, we have isolated biofilm-forming Listeria sp. from utensils used by a local milk collection dairy society at Usgao Goa, which collects milk for Goa dairy. Through biochemical tests and 16S rRNA sequence analysis, the bacterium was confirmed to be L. monocytogenes and designated as strain BN3, having GenBank accession number MF095110. We report for the first time Gram-positive L...
July 31, 2017: Archives of Microbiology
Danijel Glavač, Chao Zheng, Irena Dokli, Shu-Li You, Matija Gredičak
Asymmetric addition of indoles to cyclic α-diaryl-substituted N-acyl imines, which are generated in situ from 3-aryl 3-hydroxyisoindolinones, is described. The transformation proceeds smoothly with a broad range of indoles and isoindolinone alcohols using a SPINOL-derived chiral Brønsted acid catalyst to afford α-tetrasubstituted (3-indolyl)(diaryl)methanamines in excellent yields and enantioselectivities (up to 98% yield, up to >99:1 e.r.). The origin of stereochemical induction is supported by DFT calculations and experimental data...
August 2, 2017: Journal of Organic Chemistry
Ping Li, Xiaoqiu Dou, Mareike Müller, Chuanliang Feng, Matthew Wook Chang, Martin Frettlöh, Holger Schönherr
A generally applicable strategy to obtain mechanically robust hydrogels for the incorporation and containment of functional reporter bacteria for the microarray and microparticle-based detection and signaling of N-acyl homoserine lactone autoinducers (3OC12 HSL) at relevant concentrations is reported. For reinforcing hydrogels of 1,4-bi(phenylalanine-diglycol)-benzene (PDB), a hybrid hydrogel is formed by the combination of PDB self-assembly with Ca(2+) mediated alginate crosslinking. The different assembly mechanisms are shown not to interfere with each other and despite the more than four-fold increased moduli of the hydrogels, diffusion of autoinducers into the gels remains efficient and Escherichia coli pLuxR-green fluorescent protein (GFP) reporter bacteria are proliferating...
July 25, 2017: Macromolecular Bioscience
Swarnita Dixit, Ramesh Chand Dubey, Dinesh Kumar Maheshwari, Prahlad Kishore Seth, Vivek K Bajpai
Strain RT1 was isolated from root nodules of Lens culinaris (a lentil) and characterized as Rhizobium etli (a Gram-negative soil-borne bacterium) by 16S rDNA sequencing and phylogenetic analysis. The signaling molecules produced by R. etli (RT1) were detected and identified by high-performance liquid chromatography coupled with mass spectrometry. The most abundant and biologically active N-acyl homoserine lactone molecules (3-oxo-C8-HSL and 3-OH-C14-HSL) were detected in the ethyl acetate extract of RT1. The biological role of 3-oxo-C8-HSL was evaluated in RT1...
July 8, 2017: Brazilian Journal of Microbiology: [publication of the Brazilian Society for Microbiology]
B Jothimani, S Sureshkumar, B Venkatachalapathy
Chitin is a naturally occurring fully N-acylated biopolymer which cannot be converted into nanomaterial easily due to its inherent rigidity and chemical inertness. These properties limit the utility of chitin in nanomaterial-based applications. Therefore, our aim in the present work was, to prepare chitin like fully N-acylated derivatives with a hydrophobic moiety and study the impact on nanoparticles synthesis. We report such a fully substituted derivative, N-(Thiophene-2-acetyl)chitosan, its characterization and physicochemical studies of the nanoparticles synthesized...
October 1, 2017: Carbohydrate Polymers
Kohei Takamoto, Shohei Ohno, Norimichi Hyogo, Hiromichi Fujioka, Mitsuhiro Arisawa
Cycloisomerization is an atom economic procedure that converts dienes and enynes into cyclic molecules. To date, cycloisomerization between enamides and silylalkynes has not been explored. We found that N-acyl-N-vinyl-2-silylalkynylaniline derivatives undergo a cycloisomerization in the presence of a well-defined ruthenium hydride to give a 2,3-disubstitued indole. The vinyl and silylmethyl substituents on the 2- and 3-positions of the indole can be easily converted to other functional groups.
July 21, 2017: Journal of Organic Chemistry
Yan Zhou, Benjamin I Schwartz, Joanna Giza, Steven S Gross, Francis S Lee, Mary Jeanne Kreek
BACKGROUND: Anandamide (AEA)-dependent signaling is regulated by the catabolic enzyme fatty acid amide hydrolase (FAAH). Several lines of evidence have demonstrated that FAAH and AEA are involved in the behavioral effects of alcohol. Therefore, we investigated whether a selective FAAH inhibitor, URB597 (cyclohexylcarbamic acid 3'-[aminocarbonyl]-[1,1'-biphenyl]-3-yl ester), altered alcohol intake in mice in a voluntary alcohol drinking model. METHODS: Mice, subjected to 3 weeks of chronic intermittent access (IA) in a two-bottle choice paradigm with 24-h access every other day, developed rapid escalation of alcohol intake and high preference...
July 20, 2017: Psychopharmacology
M G Akimov, A M Ashba, N M Gretskaya, V V Bezuglov
Dopamine amides of arachidonic, docosahexaenoic, and oleic acids were found to induce apoptosis in PC12 cells, which was blocked exclusively by antagonists and preincubation agonists of the receptor GPR55, belonging to the group of non-CB1/CB2 receptors.
May 2017: Doklady. Biochemistry and Biophysics
Sheng Ming, Bo-Liang Zhao, Da-Ming Du
A bifunctional squaramide-catalysed asymmetric Michael/cyclization cascade reaction of 3-hydroxyoxindoles with α,β-unsaturated N-acylated succinimides is disclosed. With quinine-derived squaramide as the catalyst, a broad range of the desired spirooxindole lactone derivatives bearing two contiguous stereocenters were obtained in good yields (up to 89%) with high diastereoselectivities (up to >95 : 5 dr) and excellent enantioselectivities (up to 99% ee).
July 12, 2017: Organic & Biomolecular Chemistry
Yanhua Zeng, Yanli Wang, Zhiliang Yu, Yili Huang
It is known that some bacteria, especially members of the family Rhizobiaceae, have multiple N-acyl homoserine lactones (AHL) synthase genes and produce multiple AHL signals. However, how bacteria selectively utilize these multiple genes and signals to cope with changing environments is poorly understood. Ensifer adhaerens is an important microorganism in terms of biotechnology, ecology and evolutionary. In this study, we investigated the AHL-based QS system of E. adhaerens X097 and its response to different lifestyles or nutrients...
2017: Frontiers in Microbiology
Cameron L Noland, Michele D Kattke, Jingyu Diao, Susan L Gloor, Homer Pantua, Mike Reichelt, Anand K Katakam, Donghong Yan, Jing Kang, Inna Zilberleyb, Min Xu, Sharookh B Kapadia, Jeremy M Murray
Gram-negative bacteria express a diverse array of lipoproteins that are essential for various aspects of cell growth and virulence, including nutrient uptake, signal transduction, adhesion, conjugation, sporulation, and outer membrane protein folding. Lipoprotein maturation requires the sequential activity of three enzymes that are embedded in the cytoplasmic membrane. First, phosphatidylglycerol:prolipoprotein diacylglyceryl transferase (Lgt) recognizes a conserved lipobox motif within the prolipoprotein signal sequence and catalyzes the addition of diacylglycerol to an invariant cysteine...
July 25, 2017: Proceedings of the National Academy of Sciences of the United States of America
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