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Claudio D Navo, Nuria Mazo, Alberto Avenoza, Jesús H Busto, Jesús M Peregrina, Gonzalo Jiménez-Osés
The reactivity of cyclic tertiary sulfamidates derived from α-methylisoserine strongly depends on the substitution at the C and N termini. These substrates are one of the very few examples able to undergo nucleophilic ring-opening at a quaternary carbon with complete inversion of the configuration, as demonstrated both experimentally and computationally. When the sulfonamide is unprotected, the characteristic ring-opening reaction is completely silenced, which explains that the majority of the ring-opening reactions reported in the literature invoke N-alkyl or N-acyl-protected sulfamidates...
November 17, 2017: Journal of Organic Chemistry
Sumner Burstein
The subject of N-acyl amino acid conjugates has been rapidly growing in recent years, especially with regard to their analgesic and anti-inflammatory actions. The field is comprised of a large family of lipid signaling molecules whose importance is only now being fully realized. The most widely studied member is N-arachidonoyl glycine (NAGly), which differs structurally from the endocannabinoid anandamide (N-arachidonoyl ethanolamide) by a single oxygen atom and the two are metabolically related. Topics that are covered in this mini review are: biosynthetic pathways for N-acyl amino acids, receptors for N-acyl amino acids, physiological actions of N-acyl amino acids, pharmacological effects of N-acyl amino acids and molecular mechanisms believed to be responsible for their effects...
November 14, 2017: Molecular Pharmacology
You-Yu Lin, She-Hung Chan, Yu-Pu Juang, Hsin-Min Hsiao, Jih-Hwa Guh, Pi-Hui Liang
A series of N-acyl, N-alkoxycarbonyl, and N-alkylcarbamoyl derivatives of 2'-deoxy-glucosyl bearing oleanolic saponins were synthesized and evaluated against HL-60, PC-3, and HT29 tumor cancer cells. The SAR studies revealed that the activity increased in order of conjugation of 2' -amino group with carbamate > amide > urea derivatives. Lengthening the alkyl chain increased the cytotoxicity, the peak activity was found to around heptyl to nonyl substitutions. 2'-N-heptoxycarbonyl derivative 56 was found to be the most cytotoxic (IC50 = 0...
November 6, 2017: European Journal of Medicinal Chemistry
Louise Dahl Hultqvist, Maria Alhede, Tim Holm Jakobsen, Michael Givskov, Thomas Bjarnsholt
In order to study N-acyl homoserine lactone (AHL)-based quorum sensing in vivo, we present a protocol using an Escherichia coli strain equipped with a luxR-based monitor system, which in the presence of exogenous AHL molecules expresses a green fluorescent protein (GFP). Lungs from mice challenged intratracheally with alginate beads containing both a Pseudomonas aeruginosa strain together with the E. coli monitor strain can be investigated at different time points postinfection. Epifluorescent or confocal scanning laser microscopy (CSLM) is used to detect the GFP-expressing E...
2018: Methods in Molecular Biology
Yilei Liu, Gabriella Pessi, Katharina Riedel, Leo Eberl
We used comparative proteome analysis to determine the target genes of the two quorum sensing (QS) circuits in the opportunistic pathogen Burkholderia cenocepacia: the N-acyl homoserine lactone (AHL)-based CepIR system and the BDSF (B urkholderia diffusible signal factor, cis-2-dodecenoic acid)-based RpfFR system. In this book chapter, we focus on the description of the practical procedure we currently use in the laboratory to perform a sensitive GeLC-MS/MS shotgun proteomics experiment; we also briefly describe the downstream bioinformatic data analysis...
2018: Methods in Molecular Biology
Michael Rothballer, Jenny Uhl, Josie Kunze, Philippe Schmitt-Kopplin, Anton Hartmann
Quick and reliable quantitative methods requiring low amounts of sample volume are needed for the detection of N-acyl-homoserine lactones (HSL) and their degradation products N-acyl-homoserines (HS) in order to elucidate the occurrence and dynamics of these prevalent quorum-sensing molecules of Gram-negative bacteria in natural samples and laboratory model experiments. A combination of ELISA and UHPLC-MS is presented here which has proven to meet these requirements. Both methods can not only precisely detect and quantify HSLs but also their degradation products HS and thereby enable studying signaling dynamics in quorum sensing, which have been identified to play an essential role in bacterial communication...
2018: Methods in Molecular Biology
François Lépine, Sylvain Milot, Marie-Christine Groleau, Eric Déziel
High-performance liquid chromatography (HPLC) coupled in-line with mass spectrometry (MS) permits rapid and specific identification and quantification of N-acyl-L-homoserine lactones (AHLs) and 4-hydroxy-2-alkylquinolines (HAQs). We are presenting here methods for the analysis of these molecules directly from biological samples using LC/MS.
2018: Methods in Molecular Biology
Starla G Thornhill, Robert J C McLean
In most bacteria, a global level of regulation, termed quorum sensing (QS), exists involving intercellular communication via the production and response to cell density-dependent signal molecules. QS has been associated with a number of important features in bacteria including virulence regulation and biofilm formation. Consequently, there is considerable interest in understanding, detecting, and inhibiting QS. N-acylated homoserine lactones (AHLs) are used as extracellular QS signals by a variety of Gram-negative bacteria...
2018: Methods in Molecular Biology
Brittany A Law, Xianghai Liao, Kelsey S Moore, Abigail Southard, Patrick Roddy, Ruiping Ji, Zdzislaw Sculz, Ala Bielawska, P Christian Schulze, L Ashley Cowart
Accumulating data support a role for bioactive lipids as mediators of lipotixicity in cardiomyocytes. One class of these, the ceramides, constitutes a family of molecules that differ in structure and are synthesized by distinct enzymes, ceramide synthase (CerS)1-CerS6. Data support that specific ceramides and the enzymes that catalyze their formation play distinct roles in cell function. In a mouse model of diabetic cardiomyopathy, sphingolipid profiling revealed increases in not only the CerS5-derived ceramides but also in very long chain (VLC) ceramides derived from CerS2...
November 10, 2017: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Rebecca H Certner, Steven V Vollmer
Among the greatest threats to coral reefs are coral epizootics, which are increasing in frequency and severity across many reef ecosystems. In particular, white band disease (WBD) has devastated Caribbean acroporid populations since its initial outbreak in 1979. However, despite its widespread and damaging effects, the etiology of WBD remains largely unresolved. Here we examine the role of quorum sensing within bacterial communities associated with WBD-infected Acropora cervicornis. Microbial communities isolated from WBD-infected corals were exposed to quorum sensing inhibitor (QSI) - a N-acyl homoserine lactone autoinducer antagonist - and then dosed onto healthy test corals...
November 10, 2017: Environmental Microbiology
Benjamin James Frogley, Lakshika Perera, L James Wright
The first examples of amino-substituted fused-ring metallabenzenes, the cationic iridabenzofuran [Ir(C7H4O{NH2-2}{OMe-7})(CO)(PPh3)2][O3SCF3] (5) and neutral analogue Ir(C7H4{NH2-2}{OMe-7})Cl(PPh3)2 (6), can be prepared by reduction of the corresponding nitro-substituted iridabenzofurans with zinc and concentrated hydrochloric acid. N-functionalised derivatives of 5 and 6 are formed through alkylation, sulfonylation or acylation. Thus, consecutive treatments with methyl triflate and base gives the corresponding trimethylammonium-substituted iridabenzofurans while sulfonamide derivatives are formed with p-toluenesulfonyl chloride...
November 7, 2017: Chemistry: a European Journal
José A Gutiérrez-Barranquero, F Jerry Reen, María L Parages, Ronan McCarthy, Alan D W Dobson, Fergal O'Gara
In recent years, the marine environment has been the subject of increasing attention from biotechnological and pharmaceutical industries. A combination of unique physicochemical properties and spatial niche-specific substrates, in wide-ranging and extreme habitats, underscores the potential of the marine environment to deliver on functionally novel bioactivities. One such area of ongoing research is the discovery of compounds that interfere with the cell-cell signalling process called quorum sensing (QS). Described as the next generation of antimicrobials, these compounds can target virulence and persistence of clinically relevant pathogens, independent of any growth-limiting effects...
November 3, 2017: Microbial Biotechnology
K V Shevchenko, V V Bezuglov, M G Akimov, I Yu Nagaev, V P Shevchenko, N F Myasoedov
Acetyl, oleoyl, arachidonoyl, and docosahexaenoyl derivatives of the Pro-Gly-Pro-Leu peptide with a chemical purity of 99.8% were synthesized. The degradation kinetics of the Pro-Gly-Pro-Leu derivatives under the action of leucine aminopeptidase, nasal mucus, and microsomal fraction of the brain and blood of rats was studied. It was shown that the N-acyl derivatives of Pro-Gly-Pro-Leu proved to be more resistant to the action of leucine aminopeptidase and other enzyme systems. The study of the cytotoxic and anti-inflammatory activity of preparations on the mouse macrophage cell line RAW264...
September 2017: Doklady. Biochemistry and Biophysics
Neil Pj Price, Michael A Jackson, Karl E Vermillion, Judith A Blackburn, Jiakun Li, Biao Yu
Tunicamycin is a Streptomyces-derived inhibitor of eukaryotic protein N-glycosylation and bacterial cell wall biosynthesis, and is a potent and general toxin by these biological mechanisms. The antibacterial activity is dependent in part upon a π-π stacking interaction between the tunicamycin uridyl group and a specific Phe residue within MraY, a tunicamycin-binding protein in bacteria. We have previously shown that reducing the tunicamycin uridyl group to 5,6-dihydrouridyl (DHU) significantly lowers its eukaryotic toxicity, potentially by disrupting the π-stacking with the active site Phe...
November 1, 2017: Journal of Antibiotics
Haruo Sugita, Shun Kitao, Satoshi Narisawa, Ryosuke Minamishima, Shiro Itoi
In the original publication, the number of the NCTC strain used was published incorrectly. The authors apologize for the error. The error has no effect on the validity of the results and is corrected for accuracy.
October 26, 2017: Folia Microbiologica
Chelsea K Thornburg, Tyler Walter, Kevin D Walker
In this study, we demonstrate an enzyme cascade reaction using a benzoate CoA ligase (BadA), a modified nonribosomal peptide synthase (PheAT), a phenylpropanoyltransferase (BAPT), and a benzoyltransferase (NDTNBT) to produce an anticancer paclitaxel analogue and its precursor from the commercially available biosynthetic intermediate baccatin III. BAPT and NDTNBT are acyltransferases on the biosynthetic pathway to the antineoplastic drug paclitaxel in Taxus plants. For this study, we addressed the recalcitrant expression of BAPT by expressing it as a soluble maltose binding protein fusion (MBP-BAPT)...
October 25, 2017: Biochemistry
Patricia Rivera, Antoni Pastor, Sergio Arrabal, Juan Decara, Antonio Vargas, Laura Sánchez-Marín, Francisco J Pavón, Antonia Serrano, Dolores Bautista, Anna Boronat, Rafael de la Torre, Elena Baixeras, M Isabel Lucena, Fernando R de Fonseca, Juan Suárez
Protective mechanisms against drug-induced liver injury are actively being searched to identify new therapeutic targets. Among them, the anti-inflammatory N-acyl ethanolamide (NAE)-peroxisome proliferators activated receptor alpha (PPARα) system has gained much interest after the identification of its protective role in steatohepatitis and liver fibrosis. An overdose of paracetamol (APAP), a commonly used analgesic/antipyretic drug, causes hepatotoxicity, and it is being used as a liver model. In the present study, we have analyzed the impact of APAP on the liver NAE-PPARα system...
2017: Frontiers in Pharmacology
Nirali N Shah, Niharika Soni, Rekha S Singhal
Proteins and polysaccharides are among the biopolymers produced by living organisms for their structural integrity, protection, physiological functions or as reserve energy. These biopolymers are extracted from their natural matrices by humans to fulfil basic as well as convenience needs. The inquisitive human nature, ever-growing demands and resources at disposal have led to copious research in the field of biopolymer modifications. The availability of reactive sites on these biopolymers make them suitable substrates for esterification, etherification, oxidation, epoxidation, N-acylation, alkylation, etc...
October 16, 2017: International Journal of Biological Macromolecules
Petra Kralova, Michal Malon, Miroslav Soural
Herein, we report a fully stereoselective synthesis of tetrahydro-6H-benzo[e][1,4]oxazino[4,3-a][1,4]diazepine-6,12(11H)-diones from polymer-supported Fmoc-Ser(tBu)-OH. After the simple solid-phase synthesis of N-alkylated-N-acylated intermediates using various 2-nitrobenzoic acids and bromoketones, the key intermediates were obtained via trifluoroacetic acid (TFA)-mediated cleavage from the resin in the presence of triethylsilane (TES), which led to stereoselective reduction and yielded a specific configuration of the newly formed C3 chiral center...
October 19, 2017: ACS Combinatorial Science
Ipputa Tada, Yasuhiro Tanizawa, Akihito Endo, Masanori Tohno, Masanori Arita
Being an autochthonous species in humans, Lactobacillus gasseri is widely used as a probiotic for fermented products. We thoroughly compared the gene contents of 75 L. gasseri genomes and identified two intraspecific groups by the average nucleotide identity (ANI) threshold of 94%. Group I, with 48 strains, possessed 53 group-specific genes including the gassericin T cluster (9 genes) and N-acyl homoserine lactone lactonase. Group II, with 27 strains, including the type strain ATCC 33323, possessed group-specific genes with plasmid- or phage-related annotations...
2017: Bioscience of Microbiota, Food and Health
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